Wall thinning inspection technique for large-diameter piping using guided wave

International Nuclear Information System (INIS)

Miki, Masahiro; Nagashima, Yoshiaki; Endou, Masao; Kodaira, Kojiro; Maniwa, Kazuhiko

2009-01-01

Guided wave inspection technique is effective for detecting defects like corrosion in piping, because it can perform long range inspection. It is possible to expect this inspection as a method that leads to the decrease of the inspection process and its cost, because the incidental work can be reduced. Especially, the contraction effect of the inspection work is extensive in large-diameter piping inspection. In this paper, we introduce the guided wave inspection system to large-diameter piping. The feature is a guided wave sensor that can freely transform according to the curvature of inspection object, and portable inspection equipment. We discuss the result of detection examination for artificial wall-thinning in large-diameter piping using this system. (author)

78 FR 22515 - Seamless Refined Copper Pipe and Tube From Mexico: Rescission, in Part, of Antidumping Duty...

Science.gov (United States)

2013-04-16

... DEPARTMENT OF COMMERCE International Trade Administration [A-201-838] Seamless Refined Copper Pipe... Administration, International Trade Administration, Department of Commerce. DATES: Effective Date: April 16, 2013..., Import Administration, International Trade Administration, U.S. Department of Commerce, 14th Street and...

75 FR 26273 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China

Science.gov (United States)

2010-05-11

...)] Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From China AGENCY: United States... materially injured or threatened with material injury, or the establishment of an industry in the United States is materially retarded, by reason of subsidized and less-than-fair-value imports from China of...

Infrared Thermography Characterization of Defects in Seamless Pipes Using an Infrared Reflector

International Nuclear Information System (INIS)

Park, Hee Sang; Choi, Man Yong; Park, Jeong Hak; Lee, Jae Jung; Kim, Won Tae; Lee, Bo Young

2012-01-01

Infrared thermography uses infrared energy radiated from any objects above absolute zero temperature, and the range of its application has been constantly broadened. As one of the active test techniques detecting radiant energy generated when energy is applied to an object, ultrasound infrared thermography is a method of detecting defects through hot spots occurring at a defect area when 15-100 kHz of ultrasound is excited to an object. This technique is effective in detecting a wide range affected by ultrasound and vibration in real time. Especially, it is really effective when a defect area is minute. Therefore, this study conducted thermography through lock-in signal processing when an actual defect exists inside the austenite STS304 seamless pipe, which simulates thermal fatigue cracks in a nuclear power plant pipe. With ultrasound excited, this study could detect defects on the rear of a pipe by using an aluminium reflector. Besides, by regulating the angle of the aluminium reflector, this study could detect both front and rear defects as a single infrared thermography image.

Performance Measurements of a 7 mm-Diameter Hydrogen Heat Pipe

International Nuclear Information System (INIS)

Abdel-Bary, M.; Abdel-Samad, S.; Kiliana, K.; Ritman, J.; Abdel-Bary, M.; Abdel-Samad, S.

2008-01-01

A gravity assisted heat pipe with 7-mm diameter has been developed and tested to cool a liquid hydrogen target for extracted beam experiments at COSY. The liquid flowing down from the condenser surface is separated from the vapor flowing up by a thin wall 3 mm diameter plastic tube located concentrically inside the heat pipe. The heat pipe was tested at different inclination angles with respect to the horizontal plane. The heat pipe showed good operating characteristics because of the low radiation heat load from the surroundings, low heat capacity due to the small mass, higher sensitivity to heat loads (to overcome the heat load before the complete vaporization of the liquid in the target cell) due to the higher vapor speed inside the heat pipe which transfers the heat load to the condenser

Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill.

Science.gov (United States)

Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin

2017-10-01

The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

78 FR 69820 - Seamless Refined Copper Pipe and Tube From the People's Republic of China: Preliminary Results...

Science.gov (United States)

2013-11-21

...\\ \\1\\ See Seamless Refined Copper Pipe and Tube From Mexico and the People's Republic of China... and Tube From the People's Republic of China: Preliminary Results and Partial Rescission of... China (``PRC''), covering the period November 1, 2011 through October 31, 2012. The Department has...

Effects of valve characteristics and pipe diameter on water hammer phenomena

International Nuclear Information System (INIS)

Hur, J.; Kim, T. H.; Mun, B. H.; Choi, H. Y.; Lee, K. W.; Noh, T. S.

2001-01-01

The water hammer phenomena mean that the dynamic loads are induced on the pipe, the pipe support and the equipments in the system due to the sudden change of the flow velocity inside the pipe. The sudden changes are mainly caused by the valve sudden on/off and pump sudden start/trip. To develop a selection criterion of the parts to be analyzed for the water hammer, the effects of the valve characteristics and pipe diameter on the water hammer are analyzed. The analyses using Method of Characteristics (MOC) show that the effects of the valve pressure difference and the valve opening time are very significant, but the effects of the pipe diameter are not dominant

Corrosion and deposit evaluation in large diameter pipes using radiography

International Nuclear Information System (INIS)

Boateng, A.

2012-01-01

The reliability and safety of industrial equipment in the factories and processing industries are substantially influenced by degradation processes such as corrosion, erosion, deposits and blocking of pipes. These might lead to low production, unpredictable and costly shutdowns due to repair and replacement and sometimes combined environmental pollution and risk of personnel injuries. Only periodic inspection for the integrity of pipes and equipment can reduce the risk in connection with other maintenance activities. The research explored two methods of radiographic inspection techniques, the double wall technique and the tangential radiographic technique using Ir-192 for evaluating deposits and corrosion attacks across the inner and outer walls of steel pipes with diameter greater than 150 mm with or without insulation. The application of both techniques was conducted depending on pipe diameter, wall thickness, radiation source (Ir-92) and film combination. The iridium source was positioned perpendicular with respect to the pipe axis projecting the double wall of the pipe on the plated radiographic film. With the tangential radiographic technique, the source was placed tangential to the pipe wall and because of its large diameter, the source was collimated to prevent backscatter and also to focus the beam at the target area of interest. All measurements were performed on special designed test pieces to simulate corrosion attack and deposits on industrial pipes. Pitting corrosion measurements based on Tangential Radiographic Technique were more sophisticated, and therefore magnification factor and correction were used to establish the estimated pit depth on the film. The insulating material used to conserve the thermodynamic properties of the transported media had relatively negligible attenuation coefficient compared to the concrete deposit. The two explored techniques were successful in evaluating corrosion attack and deposit on the walls of the pipe and the risk

Seamless vascularized large-diameter tubular collagen scaffolds reinforced with polymer knittings for esophageal regenerative medicine

NARCIS (Netherlands)

Hoogenkamp, H.R.; Koens, M.J.W.; Geutjes, P.J.; Ainoedhofer, H.; Wanten, G.J.A.; Tiemessen, D.M.; Hilborn, J.; Gupta, B.; Feitz, W.F.J.; Daamen, W.F.; Saxena, A.K.; Oosterwijk, E.; Kuppevelt, T.H. van

2014-01-01

A clinical demand exists for alternatives to repair the esophagus in case of congenital defects, cancer, or trauma. A seamless biocompatible off-the-shelf large-diameter tubular scaffold, which is accessible for vascularization, could set the stage for regenerative medicine of the esophagus. The use

A flexible film type EMAT for inspection of small diameter pipe

Energy Technology Data Exchange (ETDEWEB)

Pei, Cuixiang; Xiao, Pan; Zhao, Siqi; Chen, Zhenmao [Xi' an Jiaotong University, Xi' an (China); Takagi, Toshiyuki [Institute of Fluid Science, Tohoku University, Sendai (Japan)

2017-08-15

Pipe structures are widely applied in industries, and different kinds of defects may occur in the structures during their long-time service. For non-destructive testing of defects in pipes of small diameter, it has to be conducted from the inner side of the pipe when there is no space for detection from the outside or the geometry of the outside tube surface is too complicated. In this work, a flexible film type Electromagnetic acoustic transducer (EMAT) probe with a dual coil configuration is developed. The new probe is flexible and can be inserted into the pipe for inspection. First, the feasibility of the new probe was studied through numerical simulation. Then the feasibility of the proposed flexible EMAT for detection of wall thinning in small diameter pipe was verified experimentally. It was found that the new EMAT method is suitable for the detection of wall thinning defects for small pipes.

78 FR 35251 - Seamless Refined Copper Pipe and Tube From the People's Republic of China: Final Results and...

Science.gov (United States)

2013-06-12

... of the order, the products covered are all seamless circular refined copper pipes and tubes.\\6\\ The..., 2011). The Department announced a refinement to its assessment practice in non-market economy cases.\\12... for the PRC- wide entity. \\12\\ See Non-Market Economy Antidumping Proceedings: Assessment of...

Film behaviour of vertical gas-liquid flow in a large diameter pipe

OpenAIRE

Zangana, Mohammed Haseeb Sedeeq

2011-01-01

Gas-liquid flow commonly occurs in oil and gas production and processing system. Large diameter vertical pipes can reduce pressure drops and so minimize operating costs. However, there is a need for research on two-phase flow in large diameter pipes to provide confidence to designers of equipments such as deep water risers. In this study a number of experimental campaigns were carried out to measure pressure drop, liquid film thickness and wall shear in 127mm vertical pipe. Total pressur...

Dynamics of large-diameter water pipes in hydroelectric power plants

Science.gov (United States)

Pavić, G.; Chevillotte, F.; Heraud, J.

2017-04-01

An outline is made of physical behaviour of water - filled large pipes. The fluid-wall coupling, the key factor governing the pipe dynamics, is discussed in some detail. Different circumferential pipe modes and the associated cut-on frequencies are addressed from a theoretical as well as practical point of view. Major attention is paid to the breathing mode in view of its importance regarding main dynamic phenomena, such as water hammer. Selected measurement results done at EDF are presented to demonstrate how an external, non-intrusive sensor can detect pressure pulsations of the breathing mode in a pressure pipe. Differences in the pressure measurement using intrusive and non-intrusive sensors reveal the full complexity of large-diameter pipe dynamics.

Interfacial area transport of bubbly flow in a small diameter pipe

International Nuclear Information System (INIS)

Hibiki, Takashi; Takamasa, Tomoji; Ishii, Mamoru

2001-01-01

In relation to the development of the interfacial area transport equation, this study focused on modeling of the interfacial area transport mechanism of vertical adiabatic air-water bubbly flows in a relatively small diameter pipe where the bubble size-to-pipe diameter ratio was relatively high and the radial motion of bubbles was restricted by the presence of the pipe wall. The sink term of the interfacial area concentration was modeled by considering wake entrainment as a possible bubble coalescence mechanism, whereas the source term was neglected by assuming negligibly small bubble breakup for low liquid velocity conditions based on visual observation. One-dimensional interfacial area transport equation with the derived sink term was evaluated by using five datasets of vertical adiabatic air-water bubbly flows measured in a 9.0 mm-diameter pipe (superficial gas velocity: 0.013-0.052 m/s, superficial liquid velocity: 0.58-1.0 m/s). The modeled interfacial area transport equation could reproduce the proper trend of the axial interfacial area transport and predict the measured interfacial area concentrations within an average relative deviation of ±11.1%. It was recognized that the present model would be promising for predicting the interfacial area transport of the examined bubbly flows. (author)

76 FR 62762 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Japan...

Science.gov (United States)

2011-10-11

... Fahrenheit, at various American Society of Mechanical Engineers (``ASME'') code stress levels. Alloy pipes made to ASTM A-335 standard must be used if temperatures and stress levels exceed those allowed for..., or pressure pipe applications. B. Finished and unfinished oil country tubular goods (``OCTG''), if...

Interfacial area concentration in gas–liquid bubbly to churn flow regimes in large diameter pipes

International Nuclear Information System (INIS)

Shen, Xiuzhong; Hibiki, Takashi

2015-01-01

Highlights: • A systematic method to predict interfacial area concentration (IAC) is presented. • A correlation for group 1 bubble void fraction is proposed. • Correlations of IAC and bubble diameter are developed for group 1 bubbles. • Correlations of IAC and bubble diameter are developed for group 2 bubbles. • The newly-developed two-group IAC model compares well with collected databases. - Abstract: This study performed a survey on existing correlations for interfacial area concentration (IAC) prediction and collected an IAC experimental database of two-phase flows taken under various flow conditions in large diameter pipes. Although some of these existing correlations were developed by partly using the IAC databases taken in the low-void-fraction two-phase flows in large diameter pipes, no correlation can satisfactorily predict the IAC in the two-phase flows changing from bubbly, cap bubbly to churn flow in the collected database of large diameter pipes. So this study presented a systematic way to predict the IAC for the bubbly-to-churn flows in large diameter pipes by categorizing bubbles into two groups (group 1: spherical or distorted bubble, group 2: cap bubble). A correlation was developed to predict the group 1 void fraction by using the void fraction for all bubble. The group 1 bubble IAC and bubble diameter were modeled by using the key parameters such as group 1 void fraction and bubble Reynolds number based on the analysis of Hibiki and Ishii (2001, 2002) using one-dimensional bubble number density and interfacial area transport equations. The correlations of IAC and bubble diameter for group 2 cap bubbles were developed by taking into account the characteristics of the representative bubbles among the group 2 bubbles and the comparison between a newly-derived drift velocity correlation for large diameter pipes and the existing drift velocity correlation of Kataoka and Ishii (1987) for large diameter pipes. The predictions from the newly

Influence of the pipe diameter on the structure of the gas-liquid interface in a vertical two-phase pipe flow

International Nuclear Information System (INIS)

Prasser, H. M.; Beyer, M.; Boettger, A.; Carl, H.; Lucas, D.; Schaffrath, A.; Schutz, P.; Weiss, F. P.; Zschau, J.

2003-01-01

Two-phase flow tests in a 194.1 mm diameter vertical pipe (DN200) with an air-water mixture are reported. Close to the upper end of a 9 m tall test section a wire-mesh sensor is installed that delivers instantaneous void fraction distributions over the entire cross section with time resolution of 2500 frames per second. The sensor disposes of 64 x 64 measuring points, which corresponds to a spatial resolution of 3 mm. Beside an fast flow visualisations, void-fraction profiles and bubble size distributions were obtained. Earlier, similar experiments were carried out in a pipe of 51.2 mm inner diameter (DN50). A comparison of the data from the two different facilities allows to study the scaling effects on void fraction profiles, bubbles size distributions and the flow patterns. In the small pipe, the increase of the air flow rate leads to a transition from bubbly via slug to churn turbulent flow. The transition to slug flow is accompanied by the appearance of a second peak in the bubble size distribution that corresponds to the class of large Taylor bubbles. A similar qualitative behaviour was found in the large pipe, though the large bubble fraction has a significantly bigger mean diameter at identical superficial velocities, the peak is less tall but wider. Bubbles move more freely than in the small pipe, since the confining action of the pipe walls to the flow is less pronounced, while the large Taylor bubbles occupy almost the entire cross section in case of the small pipe. Furthermore, the bubbles show much more deformations in the large pipe. Shapes of such large bubbles were characterised in three dimensions for the first time. They can rather be complicated and far from the shape of ideal Taylor bubbles. Also the small bubble fraction tends to bigger sizes in the large pipe

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2005-01-01

Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. The bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple cast-iron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs while the pipe remains in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct repair operations on live mains. The development effort is divided into eleven tasks. Task 1 (Program Management) and Task 2 (Establishment of Detailed Design Specifications) were completed in prior quarters while Task 3 (Design and Fabricate Ratcheting Stainless-Steel Repair Sleeves) has progressed to installing prototype sleeves in cast-iron test pipe segments. Efforts in the current quarter continued to focus on Tasks 4-8. Highly valuable lessons were learned from field tests of the 4-inch gas pipe repair robot in cast-iron pipe at Public Service Electric & Gas. (These field tests were conducted and reported last quarter.) These tests identified several design issues which need to be implemented in both the small- and large-diameter

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2004-11-01

- and large-diameter cast iron repair robots to assure their commercial success. Task 4 (Design, Fabricate and Test Patch Setting Robotic Train) progressed to the design of the control electronics and pneumatic system to inflate the bladder robotic patch setting module in the last quarter 5. In this quarter, work has been concentrated on increasing the nitrogen bladder reservoir volume to allow at least two complete patch inflation/patch setting cycles in the event the sleeve does not set all ratchets in the same row on the first attempt. This problem was observed on a few of the repair sleeves that were recently installed during field tests with the small-diameter robotic system. For Task 5 (Design & Fabricate Pipe-Wall Cleaning Robot Train with Pan/Zoom/Tilt Camera) it was observed that it will be necessary to add a stiff brush to push debris away from the immediate vicinity of the bell and spigot joints in mains having low gas velocities. Otherwise, material removed by the cleaning flails (which were found to be very effective in cleaning bell and spigot joints) simply falls to the low side of the pipe and accumulates in a pile. This accumulation can prevent the sleeve from achieving a leak free repair. Similarly, it is also necessary to design a small magnet to capture existing service tap coupons and allow their removal from the inside of the pipe. These coupons were found to cause difficulty in launching and retrieving the small pipe repair robot; one coupon lodged beneath the end of the guide shoe. These new features require redesign of the pipe wall cleaning train and modification to the patch setting train. Task 6 (Design & Build Surface Control and Monitoring System) was previously completed with the control and computer display functions being operated through LabView. However, this must now be re-visited to add control routines for the coupon catcher to be added. This will most likely include a lift-off/place-on magnet translation function. Task 7 (Design

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari, Gerard T. Pittard

2004-01-01

optimize the design of the robot elements and surface control electronics and software. Task 6 (Design & Build Surface Control and Monitoring System) has been completed with the control and computer display functions being operated through LabView. Task 7 (Design & Fabricate Large Diameter Live Access System) progressed to the design, fabrication and testing of a entry fitting in a 4-inch prototype and is now being used to complete drawings for use in 12-inch diameter pipe. Task 8--System Integration and Laboratory Validation continued developing the robot module inter-connects and development of a master LabView-based system display and control software.

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M Kothari; Gerard T. Pittard

2004-07-01

) continued with additional in-pipe testing required to optimize the design of the robot elements and surface control electronics and software. Task 6 (Design & Build Surface Control and Monitoring System) has been completed with the control and computer display functions being operated through LabView. Task 7 (Design & Fabricate Large Diameter Live Access System) progressed to completing the detailed design of the entry fitting for 12-inch diameter cast iron pipe. The fitting is now being manufactured. The 12-inch ball valve for allowing no-blow access was also procured. Task 8 (System Integration and Laboratory Validation) continued with the development of the robot module inter-connects and of a master LabView-based system display and control software.

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2004-04-01

optimize the design of the robot elements and surface control electronics and software. Task 6 (Design & Build Surface Control and Monitoring System) has been completed with the control and computer display functions being operated through LabView. Task 7 (Design & Fabricate Large Diameter Live Access System) progressed to completing the detailed design of the entry fitting for 12-inch diameter cast iron pipe. The fitting is now being placed into manufacture. Task 8--System Integration and Laboratory Validation continued developing the robot module inter-connects and development of a master LabView-based system display and control software.

78 FR 64475 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 41/2

Science.gov (United States)

2013-10-29

... stress levels. Alloy pipes made to ASTM A-335 standard must be used if temperatures and stress levels..., or pressure pipe applications. B. Finished and unfinished oil country tubular goods (OCTG), if covered by the scope of another antidumping duty order from the same country. If not covered by such an...

Evaluation of stresses in large diameter, thin walled piping at support locations

International Nuclear Information System (INIS)

Bryan, B.J.; Flanders, H.E. Jr.; Rawls, G.B. Jr.

1992-01-01

The highest stresses in many thin walled piping systems are the local stresses at the pipe supports. These secondary stresses are caused by saddles or other structural discontinuities that restrain pipe ovalization. A static analysis of a thin walled pipe supported on structural steel saddle under dead weight loading is presented. The finite element analysis is performed using a shell model with distributed gravity and hydrostatic pressure loading. Parametric studies on global and local stress are performed to determine the effect of the pipe diameter to thickness ratio. Two aspects of the saddle design are also investigated: the effect of saddle width, and the effect of saddle wrap angle. Additionally, the computed stresses are compared to closed form solutions

An experimental investigation on the pressure characteristics of high speed self-resonating pulsed waterjets influenced by feeding pipe diameter

Energy Technology Data Exchange (ETDEWEB)

Li, Dong; Kang, Dong; Ding, Xiao Long; Wang, Xiao Huan; Fang, Zhen Long [School of Power and Mechanical Engineering, Wuhan University, Hubei Province (China)

2016-11-15

The destructive power of a continuous waterjet issuing from a nozzle can be greatly enhanced by generating self-resonance in the nozzle assembly to produce a Self-resonating pulsed waterjet (SRPW). To further improve the performance of SRPW, effects of feeding pipe diameter on the pressure characteristics were experimentally investigated by measuring and analyzing the axial pressure oscillation peaks and amplitudes. Four organ-pipe nozzles of different chamber lengths and three feeding pipes of different diameters were employed. Results show that feeding pipe diameter cannot change the feature of SRPW of having an optimum standoff distance, but it slightly changes the oscillating frequency of the jet. It is also found that feeding pipe diameter significantly affects the magnitudes of pressure oscillation peak and amplitude, largely depending on the pump pressure and standoff distance. The enhancement or attenuation of the pressure oscillation peak and amplitude can be differently affected by the same feeding pipe diameter.

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2005-04-01

Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. The bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple cast-iron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs while the pipe remains in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct repair operations on live mains. The development effort is divided into eleven tasks. Task 1 (Program Management) and Task 2 (Establishment of Detailed Design Specifications) were completed previously. Task 3 (Design and Fabricate Ratcheting Stainless-Steel Repair Sleeves) has progressed to installing prototype sleeves in test cast-iron pipe segments. Efforts in the current quarter continued to be focused on Tasks 4-8. Highly valuable lessons were learned from field tests of the 4-inch gas pipe repair robot in cast-iron pipe at Public Service Electric & Gas. (These field tests were conducted and reported previously.) Several design issues were identified which need to be implemented in both the small- and large-diameter repair

Two-group interfacial area concentration correlations of two-phase flows in large diameter pipes

International Nuclear Information System (INIS)

Shen, Xiuzhong; Hibiki, Takashi

2015-01-01

The reliable empirical correlations and models are one of the important ways to predict the interfacial area concentration (IAC) in two-phase flows. However, up to now, no correlation or model is available for the prediction of the IAC in the two-phase flows in large diameter pipes. This study collected an IAC experimental database of two-phase flows taken under various flow conditions in large diameter pipes and presented a systematic way to predict the IAC for two-phase flows from bubbly, cap-bubbly to churn flow in large diameter pipes by categorizing bubbles into two groups (group-1: spherical and distorted bubble, group-2: cap bubble). Correlations were developed to predict the group-1 void fraction from the void fraction of all bubble. The IAC contribution from group-1 bubbles was modeled by using the dominant parameters of group-1 bubble void fraction and Reynolds number based on the parameter-dependent analysis of Hibiki and Ishii (2001, 2002) using one-dimensional bubble number density and interfacial area transport equations. A new drift velocity correlation for two-phase flow with large cap bubbles in large diameter pipes was derived in this study. By comparing the newly-derived drift velocity correlation with the existing drift velocity correlation of Kataoka and Ishii (1987) for large diameter pipes and using the characteristics of the representative bubbles among the group 2 bubbles, we developed the model of IAC and bubble size for group 2 cap bubbles. The developed models for estimating the IAC are compared with the entire collected database. A reasonable agreement was obtained with average relative errors of ±28.1%, ±54.4% and ±29.6% for group 1, group 2 and all bubbles respectively. (author)

Effects of residual stress on fatigue strength of small diameter welded pipe joint

International Nuclear Information System (INIS)

Yamashita, Tetsuo; Hattori, Takahiro; Nomoto, Toshiharu; Iida, Kunihiro; Sato, Masanobu

1996-01-01

A power plant consists of many welded components, therefore, it is essential in establishing the reliability of the power plant to maintain the reliability of all welded components. The fatigue failure caused by mechanical vibrations of small diameter welded joints, which is represented by socket welded joints, is one of the major causes of trouble for the welded parts of the power plant. Here, bending fatigue tests were conducted to investigate the fatigue strength of small diameter socket welded pipe joints. In the most cases of large diameter socket joints, a fatigue crack started from the root of the fillet weld though the stress amplitude at the root was smaller than that at the toe of fillet weld. Additionally, the fatigue strength was affected by the weld bead sequence. The residual stress was considered to be one of the important parameters governing fatigue strength, therefore, its effects were investigated. In several types of pipe joints, the local stress and residual stress distributions were calculated by finite element analysis. The residual stresses were compressive at the toe and tensile at the root of the socket welded joints. Based on these results, the effects of residual stresses on the fatigue strength are discussed for small diameter welded pipe joints in the present work

Seismic fragility test of a 6-inch diameter pipe system

International Nuclear Information System (INIS)

Chen, W.P.; Onesto, A.T.; DeVita, V.

1987-02-01

This report contains the test results and assessments of seismic fragility tests performed on a 6-inch diameter piping system. The test was funded by the US Nuclear Regulatory Commission (NRC) and conducted by ETEC. The objective of the test was to investigate the ability of a representative nuclear piping system to withstand high level dynamic seismic and other loadings. Levels of loadings achieved during seismic testing were 20 to 30 times larger than normal elastic design evaluations to ASME Level D limits would permit. Based on failure data obtained during seismic and other dynamic testing, it was concluded that nuclear piping systems are inherently able to withstand much larger dynamic seismic loadings than permitted by current design practice criteria or predicted by the probabilistic risk assessment (PRA) methods and several proposed nonlinear methods of failure analysis

Improvement of estimation method of two-phase flow in a large diameter pipe. 2. Development of mechanistic interfacial drag force model

International Nuclear Information System (INIS)

Okawa, Tomio; Yoneda, Kimitoshi

1998-01-01

It is experimentally clarified that behavior of gas-liquid two-phase flow in large diameter pipe is different from one occurred in small diameter pipe. However, no special model for large diameter pipe is used in existing nuclear reactor safety analysis codes. In the present study, detailed investigation about the two-phase flow model used in the safety analysis was carried out to specify the physical phenomena which should be modeled more precisely. Based on the investigation, steam-water two-phase flow experiments using large diameter pipe was conducted to obtain new models. As a result, new evaluation methods for bubble size, heterogeneous distribution of void fraction, and wake formed behind bubble were developed. These new models were applied to the prediction of steam-water two-phase flow experiments using large diameter pipes to clarify their validity. It was consequently demonstrated that the accuracy of the numerical solution is remarkably improved not only for the experiment used for model development but also for the experiment where the pipe diameter, pressure, velocities, void fraction are different. (author)

Determination of optimal tool parameters for hot mandrel bending of pipe elbows

Science.gov (United States)

Tabakajew, Dmitri; Homberg, Werner

2018-05-01

Seamless pipe elbows are important components in mechanical, plant and apparatus engineering. Typically, they are produced by the so-called `Hamburg process'. In this hot forming process, the initial pipes are subsequently pushed over an ox-horn-shaped bending mandrel. The geometric shape of the mandrel influences the diameter, bending radius and wall thickness distribution of the pipe elbow. This paper presents the numerical simulation model of the hot mandrel bending process created to ensure that the optimum mandrel geometry can be determined at an early stage. A fundamental analysis was conducted to determine the influence of significant parameters on the pipe elbow quality. The chosen methods and approach as well as the corresponding results are described in this paper.

The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system.

Science.gov (United States)

Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

2016-11-05

In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography-Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better. Copyright © 2016 Elsevier B.V. All rights reserved.

77 FR 50465 - Certain Small Diameter Carbon and Alloy Seamless Standard, Line and Pressure Pipe From Romania...

Science.gov (United States)

2012-08-21

...- 795, and the American Petroleum Institute (API) 5L specifications and meeting the physical parameters... 1000 degrees Fahrenheit, at various American Society of Mechanical Engineers (ASME) code stress levels..., line, and pressure pipes and redraw hollows produced, or equivalent, to the American Society for...

75 FR 38781 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe From Japan...

Science.gov (United States)

2010-07-06

... Fahrenheit, at various American Society of Mechanical Engineers (``ASME'') code stress levels. Alloy pipes made to ASTM A-335 standard must be used if temperatures and stress levels exceed those allowed for.... B. Finished and unfinished oil country tubular goods (``OCTG''), if covered by the scope of another...

The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

Energy Technology Data Exchange (ETDEWEB)

Liu, Jingqing [College of Engineering and Architecture, Zhejiang University, Hangzhou 310058 (China); Chen, Huanyu [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Binhai Industrial Technology Research Institute of Zhejiang University, Tianjin 300000 (China); Yao, Lingdan; Wei, Zongyuan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Lou, Liping, E-mail: loulp@zju.edu.cn [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda [Environmental Protection Agency, Office of Research and Development, NRMRL, Cincinnati, OH 45220 (United States); Hu, Baolan [College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhou, Xiaoyan [Shaoxing Water Environmental Science Institute Co. Ltd, Zhejiang 312000 (China)

2016-11-05

Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

The spatial distribution of pollutants in pipe-scale of large-diameter pipelines in a drinking water distribution system

International Nuclear Information System (INIS)

Liu, Jingqing; Chen, Huanyu; Yao, Lingdan; Wei, Zongyuan; Lou, Liping; Shan, Yonggui; Endalkachew, Sahle-Demessie; Mallikarjuna, Nadagouda; Hu, Baolan; Zhou, Xiaoyan

2016-01-01

Highlights: • First investigating the spatial distribution of pollutants in pipe-scale. • Spatial distribution of heavy metals indicated their sources were different. • Three main factors effete the distribution of pollutants. • Organic deposits mainly included microbial and microalgae metabolites. - Abstract: In large-diameter drinking water pipelines, spatial differences in hydraulic and physiochemical conditions may also result in spatial variations in pipe corrosion, biofilm growth and pollutant accumulation. In this article, the spatial distributions of various metals and organic contaminants in two 19-year-old grey cast iron pipes which had an internal diameter of 600 mm (DN600), were investigated and analyzed by Atomic Absorption Spectrometry, Gas Chromatography–Mass Spectrometry, Energy Dispersive Spectrometer, X-ray Diffraction, etc. The spatial distribution of heavy metals varied significantly across the pipe section, and iron, manganese, lead, copper, and chromium were highest in concentration in the upper portion pipe-scales. However, the highest aluminum and zinc content was detected in the lower portion pipe-scales. Apart from some common types of hydrocarbons formed by microbial metabolites, there were also some microalgae metabolites and exogenous contaminants accumulated in pipe-scale, which also exhibited high diversity between different spatial locations. The spatial distributions of the physical and chemical properties of pipe-scale and contaminants were quite different in large-diameter pipes. The finding put forward higher requirements on the research method about drinking water distribution system chemical safety. And the scientific community need understand trend and dynamics of drinking water pipe systems better.

77 FR 56809 - Certain Small Diameter Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From...

Science.gov (United States)

2012-09-14

... stress levels. Alloy pipes made to ASTM standard A-335 must be used if temperatures and stress levels... not used in standard, line or pressure applications. In addition, finished and unfinished oil country... antidumping duty order from the same country. If not covered by such an OCTG order, finished and unfinished...

Manufacture of seamless stainless steel tubings and related equipment

International Nuclear Information System (INIS)

Wali, D.K.; Chaudhary, S.

1997-01-01

Production of seamless tubes for special application is one of the important production activities of Nuclear Fuel Complex (NFC), Hyderabad. NFC had set up facility of Hot Extrusion Press and Cold Pilger Mills with related finishing and inspection equipment for manufacturing quality seamless tubes of zirconium alloy for application in nuclear power reactors in early 70''s. Being aware that the demand for seamless tube in a developing economy gradually increases till it reaches around 30 to 40% of the total requirement of tubes and pipes and also of the fact that manufacturing technology developed for production of zircaloy seamless tubes for nuclear application, can easily be harnessed and spinned off for production of seamless tubes in materials generally difficult to hot roll (in other than extrusion process), NFC augmented its seamless tube manufacturing facility by adding, a vertical piercing press, series of induction furnaces and large size pilger mills to meet existing market demand of power sector, engineering, fertilisers and petro chemical industries and any other specialised applications

Analytical study of residual stress improvement method, delta-T process for small-diameter pipe

International Nuclear Information System (INIS)

Tsuruki, Masaki; Aoike, Satoru; Okido, Shinobu; Fukuda, Yuka; Oritani, Naohiko

2012-01-01

In order to prevent initiation of stress corrosion cracking (SCC) at the inner surface of the butt-weld region of a small-diameter pipe, a residual stress improvement process called delta-T process has been developed. During delta-T process, the outer surface of pipe is heated by an external device and the inner surface is rapidly cooled by flashing water. The large thermal stress due to temperature difference between outer and inner surface could improve tensile stress to compressive one at inner surface. In this paper, the thermal elasto-plastic finite element analysis (FEA) was conducted to clarify the mechanism of delta-T process for piping system with 50A schedule 80 in nominal pipe size. The FEA results showed good agreements with experimentally measurements of temperature and residual stress in delta-T process. In addition, the management criterion to verify the application of delta-T process to piping system by measurement of temperature at outer surface of pipe was discussed by various parametric numerical analyses. (author)

76 FR 39852 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 41/2

Science.gov (United States)

2011-07-07

..., or equivalent, to the American Society for Testing and Materials (``ASTM'') A-53, ASTM A-106, ASTM A-333, ASTM A- 334, ASTM A-589, ASTM A-795, and the American Petroleum Institute (``API'') 5L... American Society of Mechanical Engineers (``ASME'') code stress levels. Alloy pipes made to ASTM A-335...

77 FR 13079 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 41/2

Science.gov (United States)

2012-03-05

... produced, or equivalent, to the American Society for Testing and Materials (``ASTM'') A-53, ASTM A-106, ASTM A-333, ASTM A- 334, ASTM A-589, ASTM A-795, and the American Petroleum Institute (``API'') 5L... American Society of Mechanical Engineers (``ASME'') code stress levels. Alloy pipes made to ASTM A-335...

Surface improvement for inside surface of small diameter pipes by laser cladding technique

International Nuclear Information System (INIS)

Irisawa, Toshio; Morishige, Norio; Umemoto, Tadahiro; Ono, Kazumichi; Hamaoka, Tadashi; Tanaka, Atsushi

1991-01-01

A laser cladding technique has been used for surface improvement in controlling the composition of a metal surface. Recent high power YAG laser development gives an opportunity to use this laser cladding technique for various applications. A YAG laser beam can be transmitted through an optical fiber for a long distance and through narrow spaces. YAG laser cladding was studied for developing alloy steel to prevent stress corrosion cracking in austenitic stainless steel piping. In order to make a cladding layer, mixed metal powder was on the inside surface of the piping using an organic binder. Subsequently the powder beds were melted with a YAG laser beam transmitted through an optical fiber. This paper introduces the Laser cladding technique for surface improvement for the inside surface of a small diameter pipe. (author)

Leak Detection in Water-Filled Small-Diameter Polyethylene Pipes by Means of Acoustic Emission Measurements

Directory of Open Access Journals (Sweden)

Alberto Martini

2016-12-01

Full Text Available The implementation of effective strategies to manage leaks represents an essential goal for all utilities involved with drinking water supply in order to reduce water losses affecting urban distribution networks. This study concerns the early detection of leaks occurring in small-diameter customers’ connections to water supply networks. An experimental campaign was carried out in a test bed to investigate the sensitivity of Acoustic Emission (AE monitoring to water leaks. Damages were artificially induced on a polyethylene pipe (length 28 m, outer diameter 32 mm at different distances from an AE transducer. Measurements were performed in both unburied and buried pipe conditions. The analysis permitted the identification of a clear correlation between three monitored parameters (namely total Hits, Cumulative Counts and Cumulative Amplitude and the characteristics of the examined leaks.

Mechanical properties of roll extruded nuclear reactor piping

International Nuclear Information System (INIS)

Steichen, J.M.; Knecht, R.L.

1975-01-01

The elevated temperature mechanical properties of large diameter (28 inches) seamless pipe produced by roll extrusion for use as primary piping for sodium coolant in the Fast Flux Test Facility (FFTF) have been characterized. The three heats of Type 316H stainless steel piping material used exhibited consistent mechanical properties and chemical compositions. Tensile and creep-rupture properties exceeded values on which the allowable stresses for ASME Code Case 1592 on Nuclear Components in Elevated Temperature Service were based. Tensile strength and ductility were essentially unchanged by aging in static sodium at 1050 0 F for times to 10,000 hours. High strain rate tensile tests showed that tensile properties were insensitive to strain rate at temperatures to 900 0 F and that for temperatures of 1050 0 F and above both strength and ductility significantly increased with increasing strain rate. Fatigue-crack propagation properties were comparable to results obtained on plate material and no differences in crack propagation were found between axial and circumferential orientations. (U.S.)

IN-SITU TEST EXPERIMENTAL RESEARCH ON LEAKAGE OF LARGE DIAMETER PRE-STRESSED CONCRETE CYLINDER PIPE (PCCP

Directory of Open Access Journals (Sweden)

Jianjun Luo

2016-10-01

Full Text Available In recent years, a big number of large diameter pre-stressed concrete cylinder pipe (PCCP lines have been applied to the Mid-route of the South-to-North Water Transfer Project. However, the leakage problem of PCCP causes annually heavy economic losses to our country. In such a context of situation, how to detect leaks rapidly and precisely after pipes appear cracks in water supply system has great significance. Based on the study and analysis of the characteristic structure of large diameter PCCP, a new leak detection system using fiber Bragg grating sensors, which can capture signals of water pressure change, is proposed. The feasibility, reliability and practicability of the system could be acceptable according to data achieved from in–situ tests. Moreover, the leak detection system can monitor in real-time of dynamic change of water pressure. The equations of the leakage quantity and water pressure have been presented in this paper, which can provide technical guidelines for large diameter PCCP lines maintenance.

Residual stress improved by water jet peening using cavitation for small-diameter pipe inner surfaces

International Nuclear Information System (INIS)

Yasuo, Nakamura; Toshizo, Ohya; Koji, Okimura

2001-01-01

As one of degradation conditions on components used in water, the overlapping effect of environment, material and stress might cause stress corrosion cracking (SCC). Especially, for the tensile residual stress produced by welding, it is particularly effective to reduce the tensile residual stress on the material surface to prevent SCC. In this paper, the residual stress improvement method using cavitation impact generated by a water jet, called Water Jet Peening (WJP), has been developed as the maintenance technology for the inner surfaces of small-diameter Ni-Cr-Fe alloy (Alloy 600) pipes. As the results, by WJP for the inner surface of Alloy 600 pipe (inner diameter; approximately 10-15 mm), we confirmed that the compressive stress generated within the range from the surface to the inner part about 0.5 mm deep and took a maximum value about 350 MPa on the surface. (author)

Numerical Simulation Analysis of Five-Step Variable-Diameter Pipe with Solid-Liquid Two-Phase Abrasive Flow Polishing

Science.gov (United States)

Li, Junye; Zhang, Hengfu; Wu, Guiling; Hu, Jinglei; Liu, Yang; Sun, Zhihui

2018-01-01

In many areas of precision machining abrasive flow polishing technology has an important role. In order to study the influence of abrasive flow on the polishing effect of variable diameter parts, the fifth step variable diameter tube was taken as the research object to analyze the dynamic pressure and turbulent kinetic energy distribution of inlet velocity on the fifth-order variable diameter tube influences. Through comparative analysis, the abrasive flow polished variable diameter pipe parts have very effective and significant polishing effect and the higher the inlet speed, the more significant the polishing effect.

Fabrication of seamless calandria tubes

International Nuclear Information System (INIS)

Saibaba, N.; Phanibabu, C.; Bhaskara Rao, C.V.; Kalidas, R.; Ganguly, C.

2002-01-01

Full text: Calandria tube is a large diameter, thin walled zircaloy-4 tube and is an important structural component of PHWR type of reactors. These tubes are lifetime components and remain during the full life of the reactor. Calandria tubes are classified as extremely thin walled tubes with a diameter to wall thickness ratio of around 96. Such thin walled tubes are conventionally produced by seam welded route comprising of extrusion of slabs followed by a series of hot and rolling passes, shaping into O-shape and eventual welding. An alternative and superior method of fabricating the calandria tubes, the seamless route, has been developed, which involves hot extrusion of mother blanks followed by three successive cold pilger reductions. Eccentricity correction of the extruded blanks is carried out on a special purpose grinding equipment to bring the wall thickness variation within permissible limits. Predominant wall thickness reductions are given during cold pilgering to ensure high Q-factor values. The texture in the finished tubes could be closely, controlled with an average f r value of 0.65. Pilgering parameters and tube guiding system have been specially designed to facilities rolling of thin walled tubes. Seamless calandria tubes have distinct advantages over welded tubes. In addition to the absence of weld, they are dimensionally more stable, lighter in weight and possess uniform grains with superior grain size. The cycle time from billet to finished product is substantially reduced and the product is amenable to high level of quality assurance. The most significant feature of the seamless route is its material recovery over welded route. Residual stresses measured in the tubes indicate that these are negligible and uniform along the length of the tube. In view of their superior quality, the first charge of seamless calandria tubes will be rolled into the first 500 MWe Pressurised Heavy Water Reactor at Tarapur

SEAMLESS TECHNOLOGY ON CIRCULAR KNITTING MACHINES

Directory of Open Access Journals (Sweden)

CRETU Viorica

2014-05-01

Full Text Available With industrial progress, the advancements in garment manufacturing have evolved from cut & sew to complete garment knitting, which produces one entire garment without sewing or linking process. Seamless knitting technology is similar to sock manufacture, the specialized circular knitting machines producing 3 dimensional garments with no side seams, with the waistband integrated with body of the garment and with knitted washing instructions and logos. The paper starts by presenting the main advantages of seamless garments but also some limitations because the technology. Because for a seamless garment, which is realized as a knitted tub, is very important to ensure the required final chest size, it was presented the main components involved: the knitting machine, the garment design and the yarns used. The knitting machines, beside the values of diameters and gauges with a great impact on the chest size, are characterized by a very innovative and complex construction. The design of a seamless garment is fundamental different compared to garments produced on a traditional way because the designer must to work backwards from a finished garment to create the knitting programme that will ultimately give the correct finished size. On the end of the paper it was presented some of the applications of the seamless products that cover intimate apparel and other bodywear, outwear, activewear and functional sportswear, upholstery, industrial, automotive and medical textiles.

Crack initiation through vibration fatigue of small-diameter pipes

International Nuclear Information System (INIS)

Comby, R.; Thebault, Y.; Papaconstantinou, T.

2002-01-01

Socket welds are used extensively for small bore piping connections in nuclear power plant systems. Numerous fatigue-related failures occurred in the past ten years mainly on safeguard systems and continue to occur frequently, showing that corrective actions did not take into account all aspects of the problem. Destructive examination of cracked small bore piping connections allowed a better understanding of failure mechanisms and a prediction of crack initiation site depending on nozzle fittings such as run pipe and small bore pipe thickness. A three-dimensional finite element model confirmed the conclusions of the lab examinations. For thick run pipes, it was shown that the failure tend to initiate predominantly at the socket weld toe or at the root, depending on the respective thickness of coupling and small bore pipe. Some additional studies, based on RSE-M code, are in progress in order to determine the maximum stresses location. Lessons learned through these investigations led to optimise the in-service inspection scope and to define solutions to be carried out to prevent failure of ''susceptible'' small bore pipe connections. Since July 2000, a large program is in progress to select all ''susceptible'' small bore pipes in safety-related systems and to apply corrective measures such as piping modifications or system operational modifications. (authors)

Automated ultrasonic pipe weld inspection. Part 1

International Nuclear Information System (INIS)

Karl Deutsch, W.A.; Schulte, P.; Joswig, M.; Kattwinkel, R.

2006-01-01

This article contains a brief overview on automated ultrasonic welded inspection for various pipe types. Some inspection steps might by carried out with portable test equipment (e.g. pipe and test), but the weld inspection in all internationally relevant specification must be automated. The pipe geometry, the production process, and the pipe usage determine the number of required probes. Recent updates for some test specifications enforce a large number of ultrasonic probes, e.g. the Shell standard. Since seamless pipes are sometimes replaced by ERW pipes and LSAW pipes (in both cases to save production cost), the inspection methods change gradually between the various pipe types. Each testing system is unique and shows its specialties which have to be discussed by supplier, testing system user and final customer of the pipe. (author)

Void fraction development in gas-liquid flow after a U-bend in a vertically upwards serpentine-configuration large-diameter pipe

Science.gov (United States)

Almabrok, Almabrok A.; Aliyu, Aliyu M.; Baba, Yahaya D.; Lao, Liyun; Yeung, Hoi

2018-01-01

We investigate the effect of a return U-bend on flow behaviour in the vertical upward section of a large-diameter pipe. A wire mesh sensor was employed to study the void fraction distributions at axial distances of 5, 28 and 47 pipe diameters after the upstream bottom bend. The study found that, the bottom bend has considerable impacts on up-flow behaviour. In all conditions, centrifugal action causes appreciable misdistribution in the adjacent straight section. Plots from WMS measurements show that flow asymmetry significantly reduces along the axis at L/D = 47. Regime maps generated from three axial locations showed that, in addition to bubbly, intermittent and annular flows, oscillatory flow occurred particularly when gas and liquid flow rates were relatively low. At this position, mean void fractions were in agreement with those from other large-pipe studies, and comparisons were made with existing void fraction correlations. Among the correlations surveyed, drift flux-type correlations were found to give the best predictive results.

Increase of reliability of contact networks of electric transport, due to increase of strength of the joint unit of pipes of different diameters

Science.gov (United States)

Sabitov, L. S.; Kashapov, N. F.; Gilmanshin, I. R.; Gatiyatov, I. Z.; Kuznetsov, I. L.

2017-09-01

The feature of the stress state of the supports of the contact networks is the presence of a joint of pipes of different diameters, the ultimate state of which is determined, as a rule, the strength of the weld. The proposed unit allows to increase the reliability and strength of the connection and also exclude the presence of a weld bead on the outer surface of the pipe of smaller diameter in the place of its attachment to the upper end of the support ring.

Pile load test on large diameter steel pipe piles in Timan-Pechora, Russia

Energy Technology Data Exchange (ETDEWEB)

McKeown, S. [Golder Associates Inc., Houston, TX (United States); Tart, B. [Golder Associates Inc., Anchorage, AK (United States); Swartz, R. [Paragon Engineering Services Inc., Houston, TX (United States)

1994-12-31

Pile load testing conducted in May and June of 1993 at the Polar Lights Ardalin project in Arkangelsk province, Russia, was documented. Pile load testing was conducted to determine the ultimate and allowable pile loads for varying pile lengths and ground temperature conditions and to provide creep test data for deformation under constant load. The piles consisted of 20 inch diameter steel pipe piles driven open ended through prebored holes into the permafrost soils. Ultimate pile capacities, adfreeze bond, and creep properties observed were discussed. 10 figs., 4 tabs.

Experimental and numerical approach on fracture behaviour of four inches diameter carbon-manganese cracked welded pipes in four point bending

International Nuclear Information System (INIS)

Semete, P.; Faidy, C.; Lautier, J.L.

2001-01-01

EDF has conducted a research programme to demonstrate the fracture resistance of carbon-manganese welded pipes. The main task of this programme consisted of testing three four inches diameter (114.3 mm O.D.) thin welded pipes (8.56 mm thick) which are representative of those of the sites. The three pipes were loaded under four point bending at a quasi-static rate at -20 C till their maximum bending moment was reached. This paper presents the experimental results, finite element calculations and their comparison with the simplified fracture assessment method of the RSE-M Code. (author)

75 FR 71146 - Seamless Refined Copper Pipe and Tube From China and Mexico

Science.gov (United States)

2010-11-22

... Copper Pipe and Tube From China and Mexico Determinations On the basis of the record \\1\\ developed in the... copper pipe and tube (``SRC pipe and tube'') from China and Mexico provided for in subheadings 7411.10.10... notification of preliminary determinations by Commerce that imports of SRC pipe and tube from China and Mexico...

Device for film deposition and implantation of ions inside pipes of low diameter

International Nuclear Information System (INIS)

Pogrebnjak, A.D.; Perekrjostov, V.I.; Tyurin, Yu.N.; Wood, B.P.

2002-01-01

Two principally new devices, which can be applied to deposit coatings inside the pipes of low diameter, have been developed. The thickness of coatings and films can be varied. To deposit coatings of a low thickness (about 2 nm) on inside pipe walls using a vacuum-arc source and a sputtering device, which is composed of the pipe applied for anode cooling, the constant magnet, the magnetic circuit, the anode, the cathode, the pipe subjected for coating deposition, the cathode holder, etc. Using this device, we have deposited TiC, Ta, Cr, TiN coatings of various thickness ranging from scores of nano-meters to several micro-meters and with very good adhesion to the substrate. To increase adhesion, we applied 10 to 20 kV voltage during ion implantation to the substrate. To study element and structure composition, we applied RBS, TEM, SEM, XRD analyses, micro-hardness, wear resistance tests and also those for corrosion resistance in acid media. Another version of the source was based on the pulsed plasma-detonation technology and applied an evaporating electrode (for implantation) and a powder, which was injected into a plasma jet. The jet velocity reached several kilometers per second. Current of several kilo-amps passed through the plasma jet and increased its energy. The produced in this way coating thickness reached 30 to 400 micro-meter. Application of the vacuum-arc source for subsequent coating deposition allowed us to improve the servicing characteristics of surface layers. We have deposited NiAl, CoAl, A1 2 O 3 , WC-Co, Hastelloy and stainless steel SS316L

Improvement of Estimation method for two-phase flow in a large-diameter pipe. Pt. 4. Effect of the inlet boundary condition of the upward flow section on flow characteristics

International Nuclear Information System (INIS)

Yoneda, Kimitoshi; Okawa, Tomio; Zhou, Shirong

1999-01-01

In nuclear power plants, many large-diameter pipes are subject to gas-liquid two-phase flow. For rational design and performance estimation, the flow in the pipes should be predicted accurately. With the correlation used at present, however, the flow analysis can not reach desirable precision. This is partly due to the lack of understanding of the two-phase flow characteristics in large-diameter pipes. Therefore, steam-water two-phase flow in a vertical pipe (155 mm i.d.) was investigated empirically. Lateral distribution data of phase volume fraction, gas velocity and bubble diameter were obtained. The effects of the inlet boundary condition were also observed. The drift velocity in the developing region was considerably affected by the inlet boundary condition. By deriving the correlation of mean bubble diameter as a function of void fraction and pressure, the empirical data was predicted with high accuracy compared with the existing correlation used in best-estimate codes of nuclear reactor safety analysis. (author)

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2005-07-01

Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. Bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple castiron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs with the pipe in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, minimize excavation, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct safe repair operations on live mains.

78 FR 41366 - Certain Large Diameter Carbon and Alloy Seamless Standard, Line, and Pressure Pipe (Over 4 1/2

Science.gov (United States)

2013-07-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-850] Certain Large Diameter... Operations, Office 1, Import Administration, International Trade Administration, U.S. Department of Commerce... Results of Antidumping Duty Administrative Review; 2011-2012 AGENCY: Import Administration, International...

Pipe whip: a summary of the damage observed in BNL pipe-on-pipe impact tests

International Nuclear Information System (INIS)

Baum, M.R.

1987-01-01

This paper describes examples of the damage resulting from the impact of a whipping pipe on a nearby pressurised pipe. The work is a by-product of a study of the motion of a whipping pipe. The tests were conducted with small-diameter pipes mounted in rigid supports and hence the results are not directly applicable to large-scale plant applications where flexible support mountings are employed. The results illustrate the influence of whipping pipe energy, impact position and support type on the damage sustained by the target pipe. (author)

Experimental and numerical study of steel pipe with part-wall defect reinforced with fibre glass sleeve

International Nuclear Information System (INIS)

Mazurkiewicz, Lukasz; Tomaszewski, Michal; Malachowski, Jerzy; Sybilski, Kamil; Chebakov, Mikhail; Witek, Maciej; Yukhymets, Peter; Dmitrienko, Roman

2017-01-01

The paper presents numerical and experimental burst pressure evaluation of the gas seamless hot-rolled steel pipe. The main goal was to estimate mechanical toughness of pipe wrapped with composite sleeve and verify selected sleeve thickness. The authors used a nonlinear explicit FE code with constitutive models which allows for steel and composite structure failure modelling. Thanks to the achieved numerical and analytical results it was possible to perform the comparison with data received from a capacity test and good correlation between the results were obtained. Additionally, the conducted analyses revealed that local reduction of pipe wall thickness from 6 mm to 2.4 mm due to corrosion defect can reduce high pressure resistance by about 40%. Finally, pipe repaired by a fibre glass sleeve with epoxy resin with 6 mm thickness turned out more resistant than an original steel pipe considering burst pressure. - Highlights: • Numerical and experimental burst pressure evaluation of steel pipe was performed. • Seamless hot-rolled steel pipe with and without corrosion defect were considered. • Local reduction of pipe wall thickness from 6 to 2.4 mm reduces resistance by 40%. • Pipe repaired by a 6 mm fibre glass sleeve was more resistant than an original pipe.

Slug Flow Analysis in Vertical Large Diameter Pipes

Science.gov (United States)

Roullier, David

The existence of slug flow in vertical co-current two-phase flow is studied experimentally and theoretically. The existence of slug flow in vertical direction implies the presence of Taylor bubbles separated by hydraulically sealed liquid slugs. Previous experimental studies such as Ombere-Ayari and Azzopardi (2007) showed the evidence of the non-existence of Taylor bubbles for extensive experimental conditions. Models developed to predict experimental behavior [Kocamustafaogullari et al. (1984), Jayanti and Hewitt. (1990) and Kjoolas et al. (2017)] suggest that Taylor bubbles may disappear at large diameters and high velocities. A 73-ft tall and 101.6-mm internal diameter test facility was used to conduct the experiments allowing holdup and pressure drop measurements at large L/D. Superficial liquid and gas velocities varied from 0.05-m/s to 0.2 m/s and 0.07 m/s to 7.5 m/s, respectively. Test section pressure varied from 38 psia to 84 psia. Gas compressibility effect was greatly reduced at 84 psia. The experimental program allowed to observe the flow patterns for flowing conditions near critical conditions predicted by previous models (air-water, 1016 mm ID, low mixture velocities). Flow patterns were observed in detail using wire-mesh sensor measurements. Slug-flow was observed for a narrow range of experimental conditions at low velocities. Churn-slug and churn-annular flows were observed for most of the experimental data-points. Cap-bubble flow was observed instead of bubbly flow at low vSg. Wire-mesh measurements showed that the liquid has a tendency to remain near to the walls. The standard deviation of radial holdup profile correlates to the flow pattern observed. For churn-slug flow, the profile is convex with a single maximum near the pipe center while it exhibits a concave shape with two symmetric maxima close to the wall for churn-annular flow. The translational velocity was measured by two consecutive wire-mesh sensor crosscorrelation. The results show

Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

CERN Document Server

American Society for Testing and Materials. Philadelphia

2011-01-01

Standard specification for Nickel-Chromium-Iron alloys (UNS N06600, N06601, N06603, N06690, N06693, N06025, N06045, and N06696), Nikel-Chromium-Cobalt-Molybdenum alloy (UNS N06617), and Nickel-Iron-Chromium-Tungsten alloy (UNS N06674) seamless pipe and tube

SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

Energy Technology Data Exchange (ETDEWEB)

Kiran M. Kothari; Gerard T. Pittard

2003-06-01

Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. The bell-and-spigot joints tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple cast-iron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs while the pipe remains in service by traveling through the pipe, cleaning each joint surface, and attaching a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, avoid traffic disruption, and eliminate any requirement to interrupt service (which results in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct repair operations on live mains. The development effort is divided into eleven tasks. Task 1-Program Management was previously completed. Two reports, one describing the program management plan and the other consisting of the technology assessment, were submitted to the DOE COR in the first quarter. Task 2-Establishment of Detailed Design Specifications and Task 3-Design and Fabricate Ratcheting Stainless-Steel Repair Sleeves are now well underway. First-quarter activities included conducting detailed analyses to determine the capabilities of coiled-tubing locomotion for entering and repairing gas mains and the first design iteration of the joint-sealing sleeve. The maximum horizontal reach of coiled tubing inside a pipeline before buckling prevents further access was calculated for a wide

Pipe rupture test results; 4 inch pipe whip tests under BWR operational condition-clearance parameter experiments

International Nuclear Information System (INIS)

Ueda, Syuzo; Isozaki, Toshikuni; Miyazaki, Noriyuki; Kurihara, Ryoichi; Kato, Rokuro; Saito, Kazuo; Miyazono, Shohachiro

1981-05-01

The purpose of pipe rupture studies in JAERI is to perform the model tests on pipe whip, restraint behavior, jet impingement and jet thrust force, and to establish the computational method for analyzing these phenomena. This report describes the experimental results of pipe whip on the pipe specimens of 4 inch in diameter under BWR condition on which the pressure is 6.77 MPa and the temperature is 285 0 C. The pipe specimens were 114.3 mm (4 inch) in diameter and 8.6 mm in thickness and 4500 mm in length. Four pipe whip restraints used in the tests were the U-bar type of 8 mm in diameter and fabricated from type 304 stainless steel. The experimental parameter was the clearance (30, 50 and 100 mm). The dynamic strain behavior of the pipe specimen and the restraints was investigated by strain gages and their residual deformation was obtained by measuring marking points provided on their surface. The Pressure-time history in the pipe specimens was also obtained by pressure gages. The maximum pipe strain is caused near the restraints and increases with increase of the clearance. The experimental results of pipe whip tests indicate the effectiveness of pipe whip restraints. The ratio of absorbed strain energy of the pipe specimen to that of the restraints is nearly constant for different clearances at the overhang length of 400 mm. (author)

Insulated pipe clamp design

International Nuclear Information System (INIS)

Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

1980-01-01

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

Surface tension effects on vertical upward annular flows in a small diameter pipe

Energy Technology Data Exchange (ETDEWEB)

Sadatomi, Michio, E-mail: sadatomi@mech.kumamoto-u.ac.jp [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Kawahara, Akimaro [Dept. of Advanced Mechanical Systems, Kumamoto Univ., 39-1, Kurokami 2-chome, Chuou-ku, Kumamoto 860-8555 (Japan); Suzuki, Aruta [Plant Design & Engineering Dept., Environment, Energy & Plant Headquarters, Hitachi Zosen Corporation, 7-89, Nankokita 1-chome, Suminoe-ku, Osaka, 559-8559 (Japan)

2016-12-15

Highlights: • Surface tension effects were clarified on annular flow in a small diameter pipe. • The mean liquid film thickness became thinner with decreasing of surface tension. • The liquid droplet fraction and the interfacial shear stress became higher with it. • New prediction methods for the above parameters were developed and validated. - Abstract: Experiments were conducted to study the surface tension effects on vertical upward annular flows in a 5 mm I.D. pipe using water and low surface tension water with a little surfactant as the test liquid and air as the test gas. Firstly, the experimental results on the mean liquid film thickness, the liquid droplet fraction and the interfacial shear stress in annular flows together with some flow pictures are presented to clarify the surface tension effects. From these, the followings are clarified: In the low surface tension case, the liquid film surface becomes rough, the liquid film thickness thin, the liquid droplet fraction high, and the interfacial shear stress high. Secondary, correlations in literatures for the respective parameters are tested against the present data. The test results show that no correlation for the respective parameters could predict well the present data. Thus, correlations are revised by accounting for the surface tension effects. The results of the experiments, the correlations tests and their revisions mentioned above are presented in the present paper.

U-PHOS Project: Development of a Large Diameter Pulsating Heat Pipe Experiment on board REXUS 22

International Nuclear Information System (INIS)

Nannipieri, P; Anichini, M; Barsocchi, L; Becatti, G; Buoni, L; Celi, F; Catarsi, A; Di Giorgio, P; Fattibene, P; Ferrato, E; Guardati, P; Mancini, E; Meoni, G; Nesti, F; Piacquadio, S; Pratelli, E; Quadrelli, L; Viglione, A S; Zanaboni, F; Mameli, M

2017-01-01

U-PHOS Project aims at analysing and characterising the behaviour of a large diameter Pulsating Heat Pipe (PHP) on board REXUS 22 sounding rocket. A PHP is a passive thermal control device where the heat is efficiently transported by means of the self-sustained oscillatory fluid motion driven by the phase change phenomena. Since, in milli-gravity conditions, buoyancy forces become less intense, the PHP diameter may be increased still maintaining the slug/plug typical flow pattern. Consequently, the PHP heat power capability may be increased too. U-PHOS aims at proving that a large diameter PHP effectively works in milli-g conditions by characterizing its thermal response during a sounding rocket flight. The actual PHP tube is made of aluminum (3 mm inner diameter, filled with FC-72), heated at the evaporator by a compact electrical resistance, cooled at the condenser by a Phase Change Material (PCM) embedded in a metallic foam. The tube wall temperatures are recorded by means of Fibre Bragg Grating (FBG) sensors; the local fluid pressure is acquired by means of a pressure transducer. The present work intends to report the actual status of the project, focusing in particular on the experiment improvements with respect to the previous campaign. (paper)

Laser cladding technology to small diameter pipes

International Nuclear Information System (INIS)

Fujimagari, H.; Hagiwara, M.; Kojima, T.

2000-01-01

A laser cladding method which produces a highly corrosion-resistant material coating layers (cladding) on the austenitic stainless steel (type 304 SS) pipe inner surface was developed to prevent SCC (stress corrosion cracking) occurrence. This technology is applicable to a narrow and long distance area from operators, because of the good accessibility of the YAG (yttrium-aluminum-garnet) laser beam that can be transmitted through an optical fiber. In this method a mixed paste metallic powder and heating-resistive organic solvent are firstly placed on the inner surface of a small pipe, and then a YAG laser beam transmitted through an optical fiber irradiates to the pasted area. A mixed paste will be melted and form a cladding layer subsequently. A cladding layer shows as excellent corrosion resistance property. This laser cladding (LC) method had already applied to several domestic nuclear power plants and had obtained a good reputation. This report introduces the outline of laser cladding technology, the developed equipment for practical application in the field, and the circumstance in actual plant application. (orig.)

Pipe inspection using the pipe crawler. Innovative technology summary report

International Nuclear Information System (INIS)

1999-05-01

The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned

Pipe inspection using the pipe crawler. Innovative technology summary report

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

Bending stresses: imposed on underground small diameter lines in city streets

Energy Technology Data Exchange (ETDEWEB)

Kottmann, A

1975-05-01

Die Technischen Werke der Stadt Stuttgart AG (TWS, Stuttgart) investigated the accuracy of available bending stress calculations to represent the actual stress exerted on underground pipelines, the effective bending intervals, and the pipe diameter required to effectively resist the expected stress. The investigation covers steel, cast iron, ductile cast iron, asbestos cement, and PVC 100. The theoretical stresses were determined by the Boussinesgne method from the effects of SLW60 vehicles on pipes buried 3.28 ft (1 m) underground. The cumulative load on the pipe was obtained as the total of the vehicle load, soil load, pipe load, and water load. Results indicate that the tensile stress from internal pipe pressure can be omitted, and that welded steel and sealed PVC pipes should account for longitudinal tensile stresses. Steel pipes are generally so oversized that they need not account for these stresses. The calculations also considered the interaction between the pipe and pipe joint as the pipe emerges from the trench for the 3 possible conditions: an overhang beam, a beam encased at one end and jointed at the other, and a beam, encased at both ends. The curves of the resisting moments varied according to the type of material and pipe diameter, with the greatest rate increase reported for asbestos cement, followed by PVC 100, cast iron, ductile cast iron, and steel. Operating data of a cast-iron underground TWS system in Stuttgart indicated that pipes with less than or equal to 4 in. ( less than or equal to 100 mm) nominal diameter were quite fragile while those with diameters >6 in. (>105 mm) sustained considerably less damage. The degree of damage was found to decrease with increasing diameters. The effect of temperature also proved important. Since it is not economically possible to reinstall the distribution lines with 8-in. (200-mm) pipes, elastic support systems such as crossing troughs are recommended to support the pipes in stress areas.

Development of on-line wall thickness gauge for small size seamless tube. Shokei seamless netsukan nikuatsukei no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Okumura, T; Konya, N; Oka, H; Kasuya, T [Kawasaki Steel Corp., Tokyo (Japan)

1991-03-01

In order to heighten the accuracy of small size seamless tube wall thickness, hot wall thickness gauge was developed to be installed, immediately behind the finishing/rolling mill, for the on-line measurement, of which the method was by the parallel-beam transmissivity of gamma-ray. The measurement unit, aiming at flexible manufacturing system (FMS), is completely automated in correcting the accuracy, changing the sizes, etc. The damping characteristics of gamma-ray beam can be expressed by a characteristic function, taking the outside diameter and wall thickness of subject tube as parameters. The functional calculation, as based on measurement of transmitted quantity of gamma-ray through the three-dimensional steel material, changes, depending upon the outside diameter, wall thickness and material specification of subject tube. System was so applied as to calculate it therefore on a case-by-case basis. Though in the vicinity of tube end, the transmitted quantity of gamma-ray is largely influenced by the horizontal dislocation, that influence is slack in the middle part of tube. Therefore, the cross sectional division was made dense and sparse in the end part and middle part, respectively of tube, which division could diminish the error from several percent to less than 0.1%. The static noise was compressed by the optimized digital filter. That gauge is presently applied for the operational administration of small size seamless tube rolling. 2 refs., 11 figs., 2 tabs.

Thermal resistance of rotating closed-loop pulsating heat pipes: Effects of working fluids and internal diameters

Directory of Open Access Journals (Sweden)

Kammuang-Lue Niti

2017-01-01

Full Text Available The objective of this study was to experimentally investigate the effects of working fluids and internal diameters on the thermal resistance of rotating closed-loop pul¬sating heat pipes (RCLPHP. The RCLPHP were made of a copper tube with internal diameters of 1.50 mm and 1.78 mm, bent into the shape of a flower petal, and arranged into a circle with 11 turns. The evaporator section was located at the outer end of the tube bundle. R123, ethanol, and water were filled as the working fluids. The RCLPHP was rotated at centrifugal accelerations 0.5, 1, 3, 5, 10, and 20 times of the gravitational acceleration considered at the connection between the evaporator and the condenser sections. The heat input was varied from 30 W to 50 W, and then to 100 W, 150 W, and 200 W. It can be concluded that when the latent heat of evaporation increases, the pressure difference between the evaporator and the condenser sections decreases, and the thermal resistance increases. Moreover, when the internal diameter increases, the driving force increases and the frictional force proportionally decreases, or the Karman number increases, and the thermal resistance decreases.

Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

Science.gov (United States)

Saibaba, N.

2008-12-01

Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties.

Fabrication of seamless calandria tubes by cold pilgering route using 3-pass and 2-pass schedules

International Nuclear Information System (INIS)

Saibaba, N.

2008-01-01

Calandria tube is a large diameter, extremely thin walled zirconium alloy tube which has diameter to wall thickness ratio as high as 90-95. Such tubes are conventionally produced by the 'welded route', which involves extrusion of slabs followed by a series of hot and cold rolling passes, intermediate anneals, press forming of sheets into circular shape and closing the gap by TIG welding. Though pilgering is a well established process for the fabrication of seamless tubes, production of extremely thin walled tubes offers several challenges during pilgering. Nuclear fuel complex (NFC), Hyderabad, has successfully developed a process for the production of Zircaloy-4 calandria tubes by adopting the 'seamless route' which involves hot extrusion of mother blanks followed by three-pass pilgering or two-pass pilgering schedules. This paper deals with standardization of the seamless route processes for fabrication of calandria tubes, comparison between the tubes produced by 2-pass and 3-pass pilgering schedules, role of ultrasonic test charts for control of process parameters, development of new testing methods for burst testing and other properties

Ice plugging of pipes using liquid nitrogen

International Nuclear Information System (INIS)

Twigg, R.J.

1987-03-01

This report presents a study on the ice plugging of pipe using liquid nitrogen, and is based on a literature review and on discussions with individuals who use the technique. Emphasis is placed on ferritic alloys, primarily carbon steels, in pipe sized up to 60 cm in diameter and on austenitic stainless steels in pipe sizes up to 30 cm in diameter. This technique is frequently used for leak testing in nuclear facilities

Basic maneuvers for an inspection robot for small diameter gas distribution mains

NARCIS (Netherlands)

Dertien, Edwin Christian; Stramigioli, Stefano

2011-01-01

This video shows the design of a mechanical structure of a miniature pipe inspection robot (MPR) capable of moving trough very small pipes (up to 41 mm inner diameter) as well as a wide range of diameters (63 to 125 mm outer diameter). The requirement to negotiate bends, T-joints and steep

Insulated pipe clamp design

International Nuclear Information System (INIS)

Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

1980-01-01

Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

Heat pipe and method of production of a heat pipe

International Nuclear Information System (INIS)

Kemp, R.S.

1975-01-01

The heat pipe consists of a copper pipe in which a capillary network or wick of heat-conducting material is arranged in direct contact with the pipe along its whole length. Furthermore, the interior space of the tube contains an evaporable liquid for pipe transfer. If water is used, the capillary network consists of, e.g., a phosphorus band network. To avoid contamination of the interior of the heat pipe during sealing, its ends are closed by mechanical deformation so that an arched or plane surface is obtained which is in direct contact with the network. After evacuation of the interior space, the remaining opening is closed with a tapered pin. The ratio wall thickness/tube diameter is between 0.01 and 0.6. (TK/AK) [de

Hitungan Diameter Pipa pada Sistem Penyediaan Air Minum sederhana

Directory of Open Access Journals (Sweden)

Wahyu Widiyanto

2010-02-01

Full Text Available Drinking water sector is one of the public services which is connected tightly to poverty decrease. A small community water supply is more suitable if it uses a simple system which does not need sophisticated planning and construction. Nevertheless, hydraulics calculation should be always conducted accurately because it will influence water supply performance. In this case, pipe hydraulics needs more overview because system reliability depends on pipe capacity. This study discusses two methods of pipe diameter calculation at a simple drinking water supply system. For planning assistance, Directorate General Cipta Karya-Public Work Ministry issued Technical Guideline Book for Simple Drinking Water Construction in 2007. One of its chapters discusses about a method to find pipe diameter based on several tables available, but it is not given an explanation about basic theory of the tables so there is a doubt for planners. For the reason, comparison between the use of the tables (Juknis Method and Darcy-Weisbach Formula to calculate pipe diameter will be discussed. Data from 5 villages in Kebumen Regency will be utilized to support analysis. The result of procedure for making comparison shows that there is no significant difference (less than 4% between the result of calculation by Darcy-Weisbach Formula and Juknis Method with accurate interpolation. Both of the methods can be applied with its advantages and disadvantages. It is suggested that Darcy-Weisbach Formula is always implemented to re-check toward pipe diameter which is available in the market and will be used in the system.

Manufacture of mold of polymeric composite water pipe reinforced charcoal

Science.gov (United States)

Zulfikar; Misdawati; Idris, M.; Nasution, F. K.; Harahap, U. N.; Simanjuntak, R. K.; Jufrizal; Pranoto, S.

2018-03-01

In general, household wastewater pipelines currently use thermoplastic pipes of Polyvinyl Chloride (PVC). This material is known to be not high heat resistant, contains hazardous chemicals (toxins), relatively inhospitable, and relatively more expensive. Therefore, researchers make innovations utilizing natural materials in the form of wood charcoal as the basic material of making the water pipe. Making this pipe requires a simple mold design that can be worked in the scale of household and intermediate industries. This research aims to produce water pipe mold with simple design, easy to do, and making time relatively short. Some considerations for molding materials are weight of mold, ease of raw material, strong, sturdy, and able to cast. Pipe molds are grouped into 4 (four) main parts, including: outer diameter pipe molding, pipe inside diameter, pipe holder, and pipe alignment control. Some materials have been tested as raw materials for outer diameter of pipes, such as wood, iron / steel, cement, and thermoset. The best results are obtained on thermoset material, where the process of disassembling is easier and the resulting mold weight is relatively lighter. For the inside diameter of the pipe is used stainless steel, because in addition to be resistant to chemical processes that occur, in this part of the mold must hold the press load due to shrinkage of raw materials of the pipe during the process of hardening (polymerization). Therefore, it needs high pressure resistant material and does not blend with the raw material of the pipe. The base of the mold is made of stainless steel material because it must be resistant to corrosion due to chemical processes. As for the adjustment of the pipe is made of ST 37 carbon steel, because its function is only as a regulator of the alignment of the pipe structure.

CREATION OF PIPE-MILL PRODUCTION AT THE REPUBLIC UNITARY ENTERPRISE “BELORUSSIAN METALLURGICAL WORKS”

Directory of Open Access Journals (Sweden)

A. V. Gontarj

2007-01-01

Full Text Available Montage and arrangement of equipment for the seamless hot-rolled pipes production is being carried out at present at RUP ‘"BMZ”. The planned date of putting into operation of production is till July, 3, 2007.

Buckling Response of a Large-Scale, Seamless, Orthogrid-Stiffened Metallic Cylinder

Science.gov (United States)

Rudd, Michelle Tillotson; Hilburger, Mark W.; Lovejoy, Andrew E.; Lindell, Michael C.; Gardner, Nathaniel W.; Schultz, Marc R.

2018-01-01

Results from the buckling test of a compression-loaded 8-ft-diameter seamless (i.e., without manufacturing joints), orthogrid-stiffened metallic cylinder are presented. This test was used to assess the buckling response and imperfection sensitivity characteristics of a seamless cylinder. In addition, the test article and test served as a technology demonstration to show the application of the flow forming manufacturing process to build more efficient buckling-critical structures by eliminating the welded joints that are traditionally used in the manufacturing of large metallic barrels. Pretest predictions of the cylinder buckling response were obtained using a finite-element model that included measured geometric imperfections. The buckling load predicted using this model was 697,000 lb, and the test article buckled at 743,000 lb (6% higher). After the test, the model was revised to account for measured variations in skin and stiffener geometry, nonuniform loading, and material properties. The revised model predicted a buckling load of 754,000 lb, which is within 1.5% of the tested buckling load. In addition, it was determined that the load carrying capability of the seamless cylinder is approximately 28% greater than a corresponding cylinder with welded joints.

Pipe rupture test results; 6 in. pipe whip test under BWR LOCA conditions

International Nuclear Information System (INIS)

Kurihara, Ryoichi; Yano, Toshikazu; Ueda, Shuzo; Isozaki, Toshikuni; Miyazaki, Noriyuki; Kato, Rokuro; Miyazono, Shohachiro

1983-02-01

A series of pipe rupture tests has been performed in JAERI to demonstrate the safety of the primary coolant circuits in the event of pipe rupture, in nuclear power plants. The present report summarizes the results of 6 in. pipe whip tests (RUN 5605, 5606), under BWR LOCA conditions (285 0 C, 6.8 MPa), which were performed in August, 1981. The test pipe is made of Type 304 stainless steel and its outer diameter is 6 in. and its thickness is 11.1 mm. The restraints are made of Type 304 stainless steel and its diameter is 16.0 mm. Two restraints were set on the restraint support with clearance of 100 mm. Overhang length was varied as the parameter in these tests and was 300 mm or 700 mm. The following results are obtained. (1) The deformations of a pipe and restraints are limited effectively by shorter overhang length of 300. However, they become larger when the overhang length is 700 mm, and the pipe deforms especially at the setting point of restraints. (2) Velocity at the free end of pipe becomes about 30 m/sec just after the break. However, velocity at the setting point of restraint becomes about only 4 m/sec just after the break. (3) It seems from the comparison between the 4 in. tests and 6 in. tests that the maximum restraint force of 6 in. tests is about two times as large as that of 4 in. tests. (author)

The development and manufacture of size for size feeder pipe for feeder replacement

International Nuclear Information System (INIS)

Legate, G.; Schreiter, D.; Townley, N.

2008-01-01

The recently recognised problem of feeder pipe thinning created a unique sourcing problem. Operators require relatively small quantities of nuclear class 1 seamless feeder pipe for such replacement which prior to the introduction of this product in 2006 was not available. It was desired that the pipe be produced at the exact size of the pipe currently in use at the specific reactor site (feeder pipe size varies from site to site). Secondly the pipe had to be made in conformance to the original code year of issue and to conform to the intent of the original material specifications. Finally a supply strategy had to be implemented allowing for timely manufacture of replacement piping. This presentation will report upon how replacement size for size feeder tube was developed and is currently manufactured at Nu-Tech Precision Metals. The paper will also detail the current supply strategy to ensure timely manufacture of the product.

Corrosion of Spiral Rib Aluminized Pipe

Science.gov (United States)

2012-08-01

Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

Fatigue strength of socket welded pipe joint

International Nuclear Information System (INIS)

Iida, K.; Matsuda, F.; Sato, M.; Higuchi, M.; Nakagawa, A.

1994-01-01

Fully reversed four point bending fatigue tests were carried out of small diameter socket welded joints made of carbon steels. Experimental parameters are pipe diameter, thickness of pipe and socket wall, throat depth and shape of fillet welds, slip-on and diametral gaps in the socket welding, lack of penetration at the root of fillet welds, and peening of fillet welds. In most cases a fatigue crack started from the root of the fillet, but in the case of higher stress amplitude, it tended to start from the toe of fillet. The standard socket welded joint of 50 mm diameter showed relatively low fatigue strength, 46 MPa in stress amplitude at the 10 7 cycles failure life. This value corresponds to about 1/5 of that of the smoothed base metal specimens in axial fatigue. The fatigue strength showed decrease with increasing pipe diameter, and increase with increasing the thickness of pipe and socket wall. The effects of throat depth and shape of fillet welds on fatigue strength were not significant. Contrary to the expectation, the fatigue strength of the socket welded joint without slip-on gap is higher than that of the joint with the normal gap. A lack of penetration at the root deleteriously reduced fatigue strength, showing 14 MPa in stress amplitude at the 10 7 cycles failure life for the 50 mm diameter socket joint. (orig.)

Ductile fracture behavior of 6-inch diameter type 304 stainless steel and STS 42 carbon steel piping containing a through-wall or part-through crack

International Nuclear Information System (INIS)

Shibata, Katsuyuki; Ohba, Toshihiro; Kawamura, Takaichi; Miyazono, Shohachiro; Kaneko, Tadashi; Yokoyama, Norio.

1986-05-01

The double ended guillotine break philosophy in the design base accident of the nuclear power plant is considered to be overly conservative from the view point of piping design. Through the past experiences and developments of the fabrication, inspection, and operation of nuclear power plants, it has been recognized that the Leak-Before-Break (LBB) concept can be justified in the LWR pressure boundary pipings. In order to verify the LBB concept, extensive experimental and theoretical works are being conducted in many countries. Furthermore, a revised piping design standard, in which LBB concept is introduced, is under preparation in Japan, U.S.A., and European countries. At JAERI, a research program to investigate the unstable ductile fracture behavior of LWR piping under bending load has been carried out as a part of the LBB verification researches since 1983. This report summarizes the result of the ductile fracture tests conducted at room temperature in 1983 and 84. The 6-inch diameter pipes of type 304 stainless steel and STS 42 carbon steel pipe with a through-wall or part-through crack were tested under bending load with low or high compliance condition at room temperature. Pipe fracture data were obtained from the test as regards to load- displacement curve, crack extension, net section stress, J-resistance curve, and so on. Besides, the influence of the compliance on the fracture behavior was examined. Discussions are performed on the ductile pipe fracture criterion, flaw evaluation criterion, and LBB evaluation method. (author)

An Experimental investigation of critical flow rates of subcooled water through short pipes with small diameters

International Nuclear Information System (INIS)

Park, Choon Kyung

1997-02-01

The primary objective of this study is to improve our understanding on critical flow phenomena in a small size leak and to develop a model which can be used to estimate the critical mass flow rates through reactor vessel or primary coolant pipe wall. For this purpose, critical two-phase flow phenomena of subcooled water through short pipes (100 ≤ L ≤ 400 mm) with small diameters (3.4 ≤ D ≤ 7.15 mm) have been experimentally investigated for wide ranges of subcooling (0∼199 .deg. C) and pressure (0.5∼2.0MPa). To examine the effects of various parameters (i.e., the location of flashing inception, the degree of subcooling, the stagnation temperature and pressure, and the pipe size) on the critical two-phase flow rates of subcooled water, a total of 135 runs were made for various combinations of test parameters using four different L/D test sections. Experimental results that show effects of various parameters on subcooled critical two-phase flow rates are presented. The measured static pressure profiles along the discharge pipe show that the critical flow rate can be strongly influenced by the flashing location. The locations of saturation pressure for different values of the stagnation subcooling have been consistently determined from the pressure profiles. Based upon the test results, two important parameters have been identified. These are cold state discharge coefficient and dimensionless subcooling, which are found to efficiently take into account the test section geometry and the stagnation conditions, respectively. A semi-empirical model has been developed to predict subcooled two-phase flow rates through small size openings. This model provides a simple and direct calculation of the critical mass flow rates with information on the initial condition and on the test section geometry. Comparisons between the mass fluxes calculated by present model and a total of 755 selected experimental data from 9 different investigators show that the agreement is

75 FR 29972 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe from the People's...

Science.gov (United States)

2010-05-28

... Determination of Sales at Less Than Fair Value AGENCY: Import Administration, International Trade Administration... sales at less than fair value in the antidumping duty investigation of certain seamless carbon and alloy... Determination of Sales at Less Than Fair Value, Affirmative Preliminary Determination of Critical Circumstances...

RESEARCH OF INFLUENCE OF THE HIGH-SPEED THERMAL PROCESSING REGIMES ON STRUCTURE AND MECHANICAL PROPERTIES OF PIPE STEEL 32G2

Directory of Open Access Journals (Sweden)

A. I. Gordienko

2012-01-01

Full Text Available Researches on influence of high-speed heating temperature, regimes of cooling and temperature of abatement on structure and mechanical properties of pipe steel 32G2 are carried out. Recommendations on the regimes of high-speed thermal processing of steel 32G2 which can be used at manufacturing of seamless pipes are given.

Further considerations for damping in heavily insulated pipe systems

International Nuclear Information System (INIS)

Anderson, M.J.; Lindquist, M.R.; Severud, L.K.

1985-01-01

Over the past several years a body of test data has been accumulated which demonstrates that damping in small diameter heavily insulated pipe systems is much larger than presently recommended by Regulatory Guide 1.61. This data is generally based on pipe systems using a stand-off insulation design with a heater annulus. Additional tests have how been completed on similar pipe systems using a strap-on insulation design without the heater annulus. Results indicate some reduction in damping over the stand-off designs. Test data has also been obtained on a larger sixteen-inch diameter heavily insulated pipe system. Results of these two additional test series are presented. Revised damping values for seismic design of heavily insulated pipe systems are then recommended

Further considerations for damping in heavily insulated pipe systems

International Nuclear Information System (INIS)

Anderson, M.J.; Lindquist, M.R.; Severud, L.K.

1985-01-01

Over the past several years a body of test data has been accumulated which demonstrates that damping in small diameter heavily insulated pipe systems is much larger than presently recommended by Regulatory Code 1.61. This data is generally based on pipe systems using a stand-off insulation design with a heater annulus. Additional tests have now been completed on similar pipe systems using a strap-on insulation design without the heater annulus. Results indicate some reduction in damping over the stand-off designs. Test data has also been obtained on a larger sixteen-inch diameter heavily insulated pipe system. Results of these two additional test series are presented. Revised damping values for seismic design for heavily insulated pipe systems are then recommended

API 5L X80 PSL2 pipes manufactured by ERW process: TenarisConfab and USIMINAS development; Tubos API 5L X80 PSL2 processados por ERW: desenvolvimento TenarisConfab-Usiminas

Energy Technology Data Exchange (ETDEWEB)

Silva, Ronaldo C.; Roza, Juliana E.; Kojima, Sergio S. [TenarisConfab, Pindamonhangaba, SP (Brazil); Miranda, Lucio S.; Turani, Leonardo O. [USIMINAS, Ipatinga, MG (Brazil)

2005-07-01

The utilization of high strength steels can decrease, both, installation and operation costs of a new pipeline, since the increase of mechanical resistance can reduce the pipe wall thickness and, consequently, the weight of the pipe. For this purpose, the manufacture of electric resistance welding (ERW) pipes is recent, and it comes as an opportunity for gas pipelines, mainly onshore projects. As a function of their larger productivity, ERW pipes are more economically attractive than those produced by seamless and SAW processes. TenarisConfab and USIMINAS, through studies and investments in manufacturing processes, have been working to increase their skills, in order to supply ERW pipes in API 5L X80 PSL2 steel. The steel elaborated by USIMINAS is low C, high Mn, Nb, V and Ti microalloyed, and with additions of Cr and Mo, aiming to produce hot rolled coils with acicular microstructure, achieved as a combination between its chemical composition and higher cooling rates after hot rolling. The results in {phi}18''(457 mm) x 0,469''(11,91 mm) pipes are presented in this article. High toughness values reached at very low temperatures suggest that ERW API 5L X80 PSL2 pipes developed by TenarisConfab and USIMINAS may be an excellent option of choice for onshore projects that request pipes in diameters up to 20''(508 mm) and thickness up to 0,500'' (12,7 mm). (author)

Piping inspection activities at the EPRI NDE Center

International Nuclear Information System (INIS)

Ammirato, F.V.

1988-01-01

Intergranular stress corrosion cracking (IGSCC) in the primary system of boiling water reactors (BWRs) has been a major reliability issue in recent years. BWR pipe cracking was first reported in 1974 with a low percentage of only small-diameter lines affected. However, with increased plant operating time, the number of reported cracking incidents has risen significantly and in 1982 and 1983 included the large-diameter recirculation lines. With the advent of cracking in large-diameter piping, innovative repair remedies were developed, such as weld overlay for repair (WOR). Although these remedies are effective in extending the service life of piping, they also present challenging NDE problems. The EPRI program for improving piping examination has aimed at systematically resolving the difficulties by optimizing techniques and procedures as well as by developing field-qualified automated examination equipment. The EPRI NDE Center's role has been the evaluation and transfer of the technology necessary to address the current piping examination problems of the nuclear utility industry. These activities normally include the following: technology assessment and improvement; validation through demonstrations and field trials; technology transfer reports, workshops, training, and qualification testing; and acquisition of relevant samples. The activities of the NDE Center are discussed

Small-bore-piping seismic-test findings

International Nuclear Information System (INIS)

Severud, L.K.; Barta, D.A.; Anderson, M.J.

1981-12-01

Description is given of a test series in which a 1-inch diameter stainless steel pipe system was subjected to dynamic testing. The test system consisted of approximately 40-feet of schedule 40 pipe, with several bends and risers, supported from a rigid test frame. FFTF prototypic pipe clamps, dead weight supports, mechanical snubbers, and insulation were utilized. Several variations of the pipe support configuration were tested. Measured test results are compared with analytical predictions for each configuration. Plans for future testing are discussed

Corrosion of Spiral Rib Aluminized Pipe : [Summary

Science.gov (United States)

2012-01-01

Large diameter, corrugated steel pipes are a common sight in the culverts that run alongside many Florida roads. Spiral-ribbed aluminized pipe (SRAP) has been widely specified by the Florida Department of Transportation (FDOT) for runoff drainage. Th...

A thin gold coated hydrogen heat pipe -cryogenic target for external experiments at cosy

International Nuclear Information System (INIS)

Abdel-Bary, M.; Abdel-Samad, S.; Elawadi, G.A.; Kilian, K.; Ritman, J.

2008-01-01

A gravity assisted Gold Coated Heat Pipe (GCHP) with 5-mm diameter has been developed and tested to cool a liquid hydrogen target for external beam experiments at COSY. The need for a narrow target diameter leads us to study the effect of reducing the heat pipe diameter to 5 mm instead of 7 mm, to study the effect of coating the external surface of the heat pipe by a polished gold layer (to decrease the radiation heat load), and to study the effect of using the heat pipe without using 20 layers super isolation around it (aluminized Mylar foil) to keep the target diameter as small as possible. The developed gold coated heat pipe was tested with 20 layers of super isolation and without. The operating characteristics for both conditions were compared to show the advantages and disadvantages

Application of LBB to a nozzle-pipe interface

Energy Technology Data Exchange (ETDEWEB)

Yu, Y.J.; Sohn, G.H.; Kim, Y.J. [and others

1997-04-01

Typical LBB (Leak-Before-Break) analysis is performed for the highest stress location for each different type of material in the high energy pipe line. In most cases, the highest stress occurs at the nozzle and pipe interface location at the terminal end. The standard finite element analysis approach to calculate J-Integral values at the crack tip utilizes symmetry conditions when modeling near the nozzle as well as away from the nozzle region to minimize the model size and simplify the calculation of J-integral values at the crack tip. A factor of two is typically applied to the J-integral value to account for symmetric conditions. This simplified analysis can lead to conservative results especially for small diameter pipes where the asymmetry of the nozzle-pipe interface is ignored. The stiffness of the residual piping system and non-symmetries of geometry along with different material for the nozzle, safe end and pipe are usually omitted in current LBB methodology. In this paper, the effects of non-symmetries due to geometry and material at the pipe-nozzle interface are presented. Various LBB analyses are performed for a small diameter piping system to evaluate the effect a nozzle has on the J-integral calculation, crack opening area and crack stability. In addition, material differences between the nozzle and pipe are evaluated. Comparison is made between a pipe model and a nozzle-pipe interface model, and a LBB PED (Piping Evaluation Diagram) curve is developed to summarize the results for use by piping designers.

Seismic ratchet-fatigue failure of piping systems

International Nuclear Information System (INIS)

Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Weiner, E.O.

1986-01-01

Failures of piping systems during earthquakes have been rare. Those that have failed were either made of brittle material such as cast iron, were rigid systems between major components where component relative seismic motions tore the pipe out of the component, or were high pressure systems where a ratchet-fatigue fracture followed a local bulging of the pipe diameter. Tests to failure of an unpressurized 3-in. and a pressurized 6-in. diameter carbon steel nuclear pipe systems subjected to high level shaking have been accomplished. Failure analyses of these tests are presented and correlated to the test results. It was found that failure of the unpressurized system could be correlated well with standard ASME type fatigue analysis predictions. Moreover, the pressurized system failure occurred in significantly less load cycles than predicted by standard fatigue analysis. However, a ratchet-fatigue and ductility exhaustion analysis of the pressurized system did correlate very well. These findings indicate modifications to design analysis methods and the present ASME Code piping design rules may be appropriate to cover the ratchet-fatigue failure mode

Experimental investigation for the optimization of heat pipe performance in latent heat thermal storage

Energy Technology Data Exchange (ETDEWEB)

Ladekar, Chandrakishor; Choudhary, S. K. [RTM Nagpur University, Wardha (India); Khandare, S. S. [B. D. College of Engineering, Wardha (India)

2017-06-15

We investigated the optimum performance of heat pipe in Latent heat thermal energy storage (LHTES), and compared it with copper pipe. Classical plan of experimentation was used to optimize the parameters of heat pipe. Heat pipe fill ratio, evaporator section length to condenser section length ratio i.e., Heat pipe length ratio (HPLR) and heat pipe diameter, was the parameter used for optimization, as result of parametric analysis. Experiment with flow rate of 10 lit./min. was conducted for different fill ratio, HPLR and different diameter. Fill ratio of 80 %, HPLR of 0.9 and heat pipe with diameter of 18 mm showed better trend in charging and discharging. Comparison between the storage tank with optimized heat pipe and copper pipe showed almost 186 % improvement in charging and discharging time compared with the copper pipe embedded thermal storage. Heat transfer between Heat transferring fluid (HTF) and Phase change material (PCM) increased with increase in area of heat transferring media, but storage density of storage tank decreased. Storage tank with heat pipe embedded in place of copper pipe is a better option in terms of charging and discharging time as well heat storage capacity due to less heat lost. This justifies the better efficiency and effectiveness of storage tank with embedded optimized heat pipe.

Process for forming seamless tubing of zirconium or titanium alloys from welded precursors

International Nuclear Information System (INIS)

Sabol, G.P.; Barry, R.F.

1987-01-01

A process is described for forming seamless tubing of a material selected from zirconium, zirconium alloys, titanium, and titanium alloys, from welded precursor tubing of the material, having a heterogeneous structure resulting from the welding thereof. The process consists of: heating successive axial segments of the welded tubing, completely through the wall thereof, including the weld, to uniformly transform the heterogeneous, as welded, material into the beta phase; quenching the beta phase tubing segments, the heating and quenching effected sufficiently rapid enough to produce a fine sized beta grain structure completely throughout the precursor tubing, including the weld, and to prevent growth of beta grains within the material larger than 200 micrometers in diameter; and subsequently uniformly deforming the quenched precursor tubing by cold reduction steps to produce a seamless tubing of final size and shape

The influence of gouge defects on failure pressure of steel pipes

International Nuclear Information System (INIS)

Alang, N A; Razak, N A; Zulfadli, M R

2013-01-01

Failure pressure of API X42 steel pipes with gouge defects was estimated through a nonlinear finite element (FE) analysis. The effect of gouge length on failure pressure of different pipe diameters was investigated. Stress modified critical strain (SMCS) model was applied as in predicting the failure of the pipe. The model uses strain based criteria to predict the failure. For validation of the model, the FE results were compared to experimental data in literature showing overall good agreement. The results show that the gouge length has significant influence on failure pressure. A smaller pipe diameter gives highest value of failure pressure

A thin gold coated hydrogen heat pipe-cryogenic target for external experiments at COSY

Science.gov (United States)

Abdel-Bary, M.; Abdel-Samad, S.; Elawadi, G. A.; Kilian, K.; Ritman, J.

2009-05-01

A gravity assisted Gold coated heat pipe (GCHP) with 5-mm diameter has been developed and tested to cool a liquid hydrogen target for external beam experiments at COSY. The need for a narrow target diameter leads us to study the effect of reducing the heat pipe diameter to 5 mm instead of 7 mm, to study the effect of coating the external surface of the heat pipe by a shiny gold layer (to decrease the radiation heat load), and to study the effect of using the heat pipe without using 20 layers of' super-insulation around it (aluminized Mylar foil) to keep the target diameter as small as possible. The developed gold coated heat pipe was tested with 20 layers of super-insulation (WI) and without super-insulation (WOI). The operating characteristics for both conditions were compared to show the advantages and disadvantages.

NOAA Seamless Raster Navigational Charts (RNC)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Seamless Raster Chart Server provides a seamless collarless mosaic of the NOAA Raster Navigational Charts (RNC). The RNC are a collection of approximately...

Development of piping support structure design software based on PDMS

International Nuclear Information System (INIS)

Tang Yongtao; Guan Hui; Su Rongfu; Huang Wei; Mao Huihui

2014-01-01

In order to enhance the efficiency of nuclear power process system piping support design, the veracity of interface with support, piping and anchor, and decrease the clash between supports and other disciplines, developed piping support structure design software NPHS based on PDMS independently. That achieved the seamless integration of PDMS and NPHS by method of embedded development, reduce the size of program code, improve the running efficiency; That predigested the 3D modeling and information storage for support parts, that increased the support database opening and maintenance using the special mechanism and configuration of database. The support modeling efficiency due to setting of the connection key point of support parts is improved. Practices in several real nuclear power projects proved that NPHS software is provided with such outstanding performances: quick running, strong stability, accurate data, easy to operate and maintain, and output results satisfied the engineering requirements. (authors)

Seamless handoff in Mobile IP

NARCIS (Netherlands)

Karagiannis, Georgios; Heijenk, Geert; El Malki, Karim; Soliman, Hesham

2001-01-01

In a system and method for handing off a mobile node in a seamless manner in a wireless access network, procedures are implemented for allowing the mobile node to synchronize the handoff with a base node (e.g., a home agent) and a correspondent node. In this way, a seamless handoff may be achieved,

Piping vibrations measured during FFTF startup

International Nuclear Information System (INIS)

Anderson, M.J.

1981-03-01

An extensive vibration survey was conducted on the Fast Flux Test Facility piping during the plant acceptance test program. The purpose was to verify that both mechanical and flow induced vibration amplitudes were of sufficiently low level so that pipe and pipe support integrity would not be compromised over the plant design lifetime. Excitation sources included main heat transport sodium pumps, reciprocating auxiliary system pumps, EM pumps, and flow oscillations. Pipe sizes varied from one-inch to twenty-eight-inches in diameter. This paper describes the test plan; the instrumentation and procedures utilized; and the test results

Laboratory exercises on oscillation modes of pipes

Science.gov (United States)

Haeberli, Willy

2009-03-01

This paper describes an improved lab setup to study the vibrations of air columns in pipes. Features of the setup include transparent pipes which reveal the position of a movable microphone inside the pipe; excitation of pipe modes with a miniature microphone placed to allow access to the microphone stem for open, closed, or conical pipes; and sound insulation to avoid interference between different setups in a student lab. The suggested experiments on the modes of open, closed, and conical pipes, the transient response of a pipe, and the effect of pipe diameter are suitable for introductory physics laboratories, including laboratories for nonscience majors and music students, and for more advanced undergraduate laboratories. For honors students or for advanced laboratory exercises, the quantitative relation between the resonance width and damping time constant is of interest.

Experimental and analytical studies on creep failure of reactor coolant piping

Energy Technology Data Exchange (ETDEWEB)

Maeda, Akio; Maruyama, Yu; Hashimoto, Kazuichiro; Harada, Yuhei; Shibazaki, Hiroaki; Kudo, Tamotsu; Hidaka, Akihide; Sugimoto, Jun [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Nakamura, N.

1999-07-01

Thermal and structural responses of reactor coolant piping under and elevated internal pressure and temperature are being investigated in WIND project at JAERI. In a recent failure test in which a nuclear grade type 316 stainless steel pipe with an outer diameter of 114.3 mm and a wall thickness of 13.5 mm was used and an internal pressure was kept at approximately 15 MPa. A failure of the piping was observed when the temperature was sustained at 970degC for one hour. In parallel with conducting the tests, post-test analyses were performed. The objective of the analyses is to assess analytical models for the creep deformation and failure of the piping at elevated internal pressure and temperature simulating thermal-hydraulic conditions during a severe accident. The major material properties needed for the analysis were measured at elevated temperatures. Coefficients of a creep constitutive equation including the tertiary stage were determined with the measured creep data and incorporated into ABAQUS code. The analysis reasonably reproduced the time history of the enlargement of the piping diameter, and the wall thickness and the diameter of the piping at the failure. It was also found that the piping failure timing obtained from the analysis agreed well with the test result. (author)

Experimental and analytical studies on creep failure of reactor coolant piping

International Nuclear Information System (INIS)

Maeda, Akio; Maruyama, Yu; Hashimoto, Kazuichiro; Harada, Yuhei; Shibazaki, Hiroaki; Kudo, Tamotsu; Hidaka, Akihide; Sugimoto, Jun; Nakamura, N.

1999-01-01

Thermal and structural responses of reactor coolant piping under and elevated internal pressure and temperature are being investigated in WIND project at JAERI. In a recent failure test in which a nuclear grade type 316 stainless steel pipe with an outer diameter of 114.3 mm and a wall thickness of 13.5 mm was used and an internal pressure was kept at approximately 15 MPa. A failure of the piping was observed when the temperature was sustained at 970degC for one hour. In parallel with conducting the tests, post-test analyses were performed. The objective of the analyses is to assess analytical models for the creep deformation and failure of the piping at elevated internal pressure and temperature simulating thermal-hydraulic conditions during a severe accident. The major material properties needed for the analysis were measured at elevated temperatures. Coefficients of a creep constitutive equation including the tertiary stage were determined with the measured creep data and incorporated into ABAQUS code. The analysis reasonably reproduced the time history of the enlargement of the piping diameter, and the wall thickness and the diameter of the piping at the failure. It was also found that the piping failure timing obtained from the analysis agreed well with the test result. (author)

Evaluation of flawed-pipe experiments: Final report

Energy Technology Data Exchange (ETDEWEB)

Zahoor, A.; Gamble, R.M.

1986-11-01

The purpose of this work was to perform elastic plastic fracture mechanics evaluations of experimental data that have become available from the NRC Degraded Pipe Program, Phase II (DPII) and other NRC and EPRI sponsored programs. These evaluations were used to assess flaw evaluation procedures for austenitic and ferritic steel piping. The results also have application to leak before break fracture mechanics analysis. An improved relationship was developed for computing the J-Integral for pipes containing throughwall flaws and loaded in pure bending. The results from several DPII experiments were compared to predictions based on new J estimation scheme solutions for circumferential, finite length part-throughwall flaws in pipes with bending loading. Comparisons of experimental maximum loads with those predicted using procedures in Paragraph IWB-3640, Section XI of the ASME Code indicate that the Code flaw evaluation procedures and allowables for austenitic steel pipe are appropriate and conservative. However, the comparisons also indicate that the base metal Code allowable loads may be about 15 to 20% high for small diameter piping (less than 8-inch diameter) at allowable a/t larger than about 0.5. The work further indicates that there is justification for reducing the conservatism in IWB-3640 allowable flaw sizes and loads for austenitic steel pipe with submerged or shielded metal arc welds.

Experimental benchmark for piping system dynamic-response analyses

International Nuclear Information System (INIS)

1981-01-01

This paper describes the scope and status of a piping system dynamics test program. A 0.20 m(8 in.) nominal diameter test piping specimen is designed to be representative of main heat transport system piping of LMFBR plants. Particular attention is given to representing piping restraints. Applied loadings consider component-induced vibration as well as seismic excitation. The principal objective of the program is to provide a benchmark for verification of piping design methods by correlation of predicted and measured responses. Pre-test analysis results and correlation methods are discussed

Experimental benchmark for piping system dynamic response analyses

International Nuclear Information System (INIS)

Schott, G.A.; Mallett, R.H.

1981-01-01

The scope and status of a piping system dynamics test program are described. A 0.20-m nominal diameter test piping specimen is designed to be representative of main heat transport system piping of LMFBR plants. Attention is given to representing piping restraints. Applied loadings consider component-induced vibration as well as seismic excitation. The principal objective of the program is to provide a benchmark for verification of piping design methods by correlation of predicted and measured responses. Pre-test analysis results and correlation methods are discussed. 3 refs

Magnetic Actuator with Multiple Vibration Components Arranged at Eccentric Positions for Use in Complex Piping

Directory of Open Access Journals (Sweden)

Hiroyuki Yaguchi

2016-06-01

Full Text Available This paper proposes a magnetic actuator using multiple vibration components to perform locomotion in a complex pipe with a 25 mm inner diameter. Due to the desire to increase the turning moment in a T-junction pipe, two vibration components were attached off-center to an acrylic plate with an eccentricity of 2 mm. The experimental results show that the magnetic actuator was able to move at 40.6 mm/s while pulling a load mass of 20 g in a pipe with an inner diameter of 25 mm. In addition, this magnetic actuator was able to move stably in U-junction and T-junction pipes. If a micro-camera is implemented in the future, the inspection of small complex pipes can be enabled. The possibility of inspection in pipes with a 25 mm inner diameter was shown by equipping the pipe with a micro-camera.

Development of three-dimensional phasic-velocity distribution measurement in a large-diameter pipe

International Nuclear Information System (INIS)

Kanai, Taizo; Furuya, Masahiro; Arai, Takahiro; Shirakawa, Kenetsu

2011-01-01

A wire-mesh sensor (WMS) can acquire a void fraction distribution at a high temporal and spatial resolution and also estimate the velocity of a vertical rising flow by investigating the signal time-delay of the upstream WMS relative to downstream. Previously, one-dimensional velocity was estimated by using the same point of each WMS at a temporal resolution of 1.0 - 5.0 s. The authors propose to extend this time series analysis to estimate the multi-dimensional velocity profile via cross-correlation analysis between a point of upstream WMS and multiple points downstream. Bubbles behave in various ways according to size, which is used to classify them into certain groups via wavelet analysis before cross-correlation analysis. This method was verified by air-water straight and swirl flows within a large-diameter vertical pipe. The results revealed that for the rising straight and swirl flows, large scale bubbles tend to move to the center, while the small bubble is pushed to the outside or sucked into the space where the large bubbles existed. Moreover, it is found that this method can estimate the rotational component of velocity of the swirl flow as well as measuring the multi-dimensional velocity vector at high temporal resolutions of 0.2s. (author)

ANSPipe: An IBM-PC interactive code for pipe-break assessment

International Nuclear Information System (INIS)

Fullwood, R.R.; Harrington, M.

1988-01-01

The advanced neutron source (ANS) being designed at Oak Ridge National Laboratory will be the world's highest flux neutron source and best facility for associated basic and applied research. The ANSPipe code was written as an aid for the piping configuration and material selection to enhance safety and availability. The primary calculation is based on the Thomas mode. which models pipe leak or break probabilities as proportional to the length of the segment and diameter and the inverse square of the wall thickness. This scaling, based on experience, is adjusted for radiation effects, using the Regulatory Guide 1.99 model, and for cyclic fatigue, stress corrosion, and inspection, using adaptations form the PRAISE-B code. The key to an ANSPipe analysis is the definition of the pipe segments. A pipe segment is defined as a length of pipe in which all the parameters affecting the pipe are constant or reasonably so. Thus, a segment would be a length of pipe of constant diameter, thickness, material type, internal pressure, flux distribution, stress, and submergence or nonsubmergence

A simplified LBB evaluation procedure for austenitic and ferritic steel piping

International Nuclear Information System (INIS)

Gamble, R.M.; Wichman, K.R.

1997-01-01

The NRC previously has approved application of LBB analysis as a means to demonstrate that the probability of pipe rupture was extremely low so that dynamic loads associated with postulated pipe break could be excluded from the design basis (1). The purpose of this work was to: (1) define simplified procedures that can be used by the NRC to compute allowable lengths for circumferential throughwall cracks and assess margin against pipe fracture, and (2) verify the accuracy of the simplified procedures by comparison with available experimental data for piping having circumferential throughwall flaws. The development of the procedures was performed using techniques similar to those employed to develop ASME Code flaw evaluation procedures. The procedures described in this report are applicable to pipe and pipe fittings with: (1) wrought austenitic steel (Ni-Cr-Fe alloy) having a specified minimum yield strength less than 45 ksi, and gas metal-arc, submerged arc and shielded metal-arc austentic welds, and (2) seamless or welded wrought carbon steel having a minimum yield strength not greater than 40 ksi, and associated weld materials. The procedures can be used for cast austenitic steel when adequate information is available to place the cast material toughness into one of the categories identified later in this report for austenitic wrought and weld materials

A simplified LBB evaluation procedure for austenitic and ferritic steel piping

Energy Technology Data Exchange (ETDEWEB)

Gamble, R.M.; Wichman, K.R.

1997-04-01

The NRC previously has approved application of LBB analysis as a means to demonstrate that the probability of pipe rupture was extremely low so that dynamic loads associated with postulated pipe break could be excluded from the design basis (1). The purpose of this work was to: (1) define simplified procedures that can be used by the NRC to compute allowable lengths for circumferential throughwall cracks and assess margin against pipe fracture, and (2) verify the accuracy of the simplified procedures by comparison with available experimental data for piping having circumferential throughwall flaws. The development of the procedures was performed using techniques similar to those employed to develop ASME Code flaw evaluation procedures. The procedures described in this report are applicable to pipe and pipe fittings with: (1) wrought austenitic steel (Ni-Cr-Fe alloy) having a specified minimum yield strength less than 45 ksi, and gas metal-arc, submerged arc and shielded metal-arc austentic welds, and (2) seamless or welded wrought carbon steel having a minimum yield strength not greater than 40 ksi, and associated weld materials. The procedures can be used for cast austenitic steel when adequate information is available to place the cast material toughness into one of the categories identified later in this report for austenitic wrought and weld materials.

OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

Energy Technology Data Exchange (ETDEWEB)

Varley, Robert [Lockheed Martin Corporation, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates, Houston, TX (United States); Johnson, Peter [BMT Scientific Marine Services, Inc., Houston, TX (United States); Shi, Shan [Houston Offshore Engineering, Houston, TX (United States); Marinho, Thiago [Federal Univ. of Rio de Janeiro (Brazil). LabOceano

2014-05-09

A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

Protection of Buried Pipe under Repeated Loading by Geocell Reinforcement

Science.gov (United States)

Khalaj, Omid; Joz Darabi, N.; Moghaddas Tafreshi, S. N.; Mašek, Bohuslav

2017-12-01

With increase in cities’ population and development of urbane life, passing buried pipelines near ground’s surface is inevitable in urban areas, roads, subways and highways. This paper presents the results of three-dimensional full scale model tests on high-density polyethylene (HDPE) pipe with diameter of 250 mm in geocell reinforced soil, subjected to repeated loading to simulate the vehicle loads. The effect of geocell’s pocket size (55*55 mm and 110*110 mm) and embedment depth of buried pipe (1.5 and 2 times pipe diameter) in improving the behaviour of buried pipes was investigated. The geocell’s height of 100 mm was used in all tests. The repeated load of 800 kPa was applied on circular loading plate with diameter of 250 mm. The results show that the pipe displacement, soil surface settlement and transferred pressure on the pipe’s crown has been influenced significantly upon the use of geocells. For example, the vertical diametric strain (VDS) and soil surface settlement (SSS), in a way that using a geocell with pocket size of 110*110 mm reduces by 27% and 43%, respectively, compared with the unreinforced one. Meanwhile, by increasing buried depth of pipe from 1.5D to 2D, the use of geocell of 110*110 mm delivers about 50% reduction in SSS and VDS, compared with the unreinforced soil.

Study on flow-induced vibration of large-diameter pipings in a sodium-cooled fast reactor. Influence of elbow curvature on velocity fluctuation field

International Nuclear Information System (INIS)

Ono, Ayako; Kimura, Nobuyuki; Kamide, Hideki; Tobita, Akira

2010-02-01

The main cooling system of Japan Sodium-cooled Fast Reactor (JSFR) consists of two loops to reduce the plant construction cost. In the design of JSFR, sodium coolant velocity is beyond 9m/s in the primary hot leg pipe with large-diameter (1.3m). The maximum Reynolds number in the piping reaches 4.2x10 7 . The hot leg pipe having a 90 degree elbow with curvature ratio of r/D=1.0, so-called 'short elbow', which enables a compact reactor vessel. In sodium cooled fast reactors, the system pressure is so low that thickness of pipings in the cooling system is thinner than that in LWRs. Under such a system condition in the cooling system, the flow-induced vibration (FIV) is concerned at the short elbow. The evaluation of the structural integrity of pipings in JSFR should be conducted based on a mechanistic approach of FIV at the elbow. It is significant to obtain the knowledge of the fluctuation intensity and spectra of velocity and pressure fluctuations in order to grasp the mechanism of the FIV. In this study, water experiments were conducted. Two types of 1/8 scaled elbows with different curvature ratio, r/D=1.0, 1.5, were used to investigate the influence of curvature on velocity fluctuation at the elbow. The velocity fields in the elbows were measured using a high speed PIV method. Unsteady behavior of secondary flow at the elbow outlet and separation flow at the inner wall of elbow were observed in the two types of elbows. It was found that the growth of secondary flow correlated with the flow fluctuation near the inside wall of the elbow. (author)

The measurement of gas–liquid two-phase flows in a small diameter pipe using a dual-sensor multi-electrode conductance probe

International Nuclear Information System (INIS)

Zhai, Lu-Sheng; Bian, Peng; Han, Yun-Feng; Gao, Zhong-Ke; Jin, Ning-De

2016-01-01

We design a dual-sensor multi-electrode conductance probe to measure the flow parameters of gas–liquid two-phase flows in a vertical pipe with an inner diameter of 20 mm. The designed conductance probe consists of a phase volume fraction sensor (PVFS) and a cross-correlation velocity sensor (CCVS). Through inserting an insulated flow deflector in the central part of the pipe, the gas–liquid two-phase flows are forced to pass through an annual space. The multiple electrodes of the PVFS and the CCVS are flush-mounted on the inside of the pipe wall and the outside of the flow deflector, respectively. The geometry dimension of the PVFS is optimized based on the distribution characteristics of the sensor sensitivity field. In the flow loop test of vertical upward gas–liquid two-phase flows, the output signals from the dual-sensor multi-electrode conductance probe are collected by a data acquisition device from the National Instruments (NI) Corporation. The information transferring characteristics of local flow structures in the annular space are investigated using the transfer entropy theory. Additionally, the kinematic wave velocity is measured based on the drift velocity model to investigate the propagation behavior of the stable kinematic wave in the annular space. Finally, according to the motion characteristics of the gas–liquid two-phase flows, the drift velocity model based on the flow patterns is constructed to measure the individual phase flow rate with higher accuracy. (paper)

Experimental and modeling hydraulic studies of foam drilling fluid flowing through vertical smooth pipes

Directory of Open Access Journals (Sweden)

Amit Saxena

2017-06-01

Full Text Available Foam has emerged as an efficient drilling fluid for the drilling of low pressure, fractured and matured reservoirs because of its the ability to reduce formation damage, fluid loss, differential sticking etc. However the compressible nature along with its complicated rheology has made its implementation a multifaceted task. Knowledge of the hydrodynamic behavior of drilling fluid within the borehole is the key behind successful implementation of drilling job. However, little effort has been made to develop the hydrodynamic models for the foam flowing with cuttings through pipes of variable diameter. In the present study, hydrodynamics of the foam fluid was investigated through the vertical smooth pipes of different pipe diameters, with variable foam properties in a flow loop system. Effect of cutting loading on pressure drop was also studied. Thus, the present investigation estimates the differential pressure loss across the pipe. The flow loop permits foam flow through 25.4 mm, 38.1 mm and 50.8 mm diameter pipes. The smaller diameter pipes are used to replicate the annular spaces between the drill string and wellbore. The developed model determines the pressure loss along the pipe and the results are compared with a number of existing models. The developed model is able to predict the experimental results more accurately.

Space qualification of high capacity grooved heat pipes

Energy Technology Data Exchange (ETDEWEB)

Dubois, M; Mullender, B; Druart, J [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W; Beddows, A [ESTEC-The (Netherlands)

1997-12-31

Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

Space qualification of high capacity grooved heat pipes

Energy Technology Data Exchange (ETDEWEB)

Dubois, M.; Mullender, B.; Druart, J. [SABCA, Societe Anomyme Belgel de Construction Aeronautique (Belgium); Supper, W.; Beddows, A. [ESTEC-The (Netherlands)

1996-12-31

Based on the thermal requirements of the future telecommunication satellites, the development of a High Capacity Grooved Heat Pipe (HPG), was contracted by ESA to SABCA leading to an aluminium extruded heat pipe (outer diameter of 25 mm) based on a multi re-entrant grooves design. After an intensive acceptance test campaign whose results showed a good confidence in the design and the fulfillment of the required specifications of heat transport and on tilt capability (experimental maximum heat transport capability of 1500 Watt metres for a vapour temperature of 20 deg C), similar heat pipes have been developed with various outer diameters (11 mm, 15 mm and 20 mm) and with various shapes (circular outer shapes, integrated saddles). Several of these heat pipes were tested during two parabolic flight campaigns, by varying the heat loads during the micro-gravity periods. This HGP heat pipe family is now being submitted to a space qualification program according to ESA standards (ESA PSS-49), both in straight and bent configuration. Within this qualification, the heat pipes are submitted to an extended test campaign including environmental (random/sinus vibration, constant acceleration) and thermal tests (thermal performance, thermal cycle, thermal soak, ageing). (authors) 9 refs.

Development of remote pipe cutting tool for divertor cassettes in JT-60SA

International Nuclear Information System (INIS)

Hayashi, Takao; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira

2014-01-01

Remote pipe cutting tool accessing from inside pipe has been newly developed for JT-60SA. The tool head equips a disk-shaped cutter blade and four rollers which are subjected to the reaction force. The tool pushes out the cutter blade by decreasing the distance between two cams. The tool cuts a cooling pipe by both pushing out the cutter blade and rotating the tool head itself. The roller holder is not pushed out anymore after touching the inner wall of the pipe. In other words, only cutter blade is pushed out after bringing the tool axis into the pipe axis. Outer diameter of the cutting tool head is 44 mm. The cutting tool is able to push out the cutter blade up to 32.5 mm in radius, i.e. 65 mm in diameter, which is enough to cut the pipe having an outer diameter of 59.8 mm. The thickness and material of the cooling pipe are 2.8 mm and SUS316L, respectively. The length of the cutting tool head is about 1 m. The tool is able to cut a pipe locates about 480 mm in depth from the mounting surface on the divertor cassette. The pipe cutting system equips two cutting heads and they are able to cut two pipes at the same time in order to remove the inner target plate. Reproducibility of the cross-sectional shape of the cut pipe is required for re-welding. The degree of reproducibility is inside 0.1 mm except for burr at outside of the pipe, which is enough to re-weld the cut pipe. Some swarf is generated during cutting the double-layered pipe assuming a plug located on the top of the pipe. The swarf is deposited on the bottom of the plug and collected by pulling out the plug in the actual equipment

Pipe support for use in a nuclear system

International Nuclear Information System (INIS)

Pollono, L.P.; Mello, R.M.

1976-01-01

Description is given of a vertical pipe support system. It comprises a tubular pipe support structure having the same inside diameter and the same wall thickness as the pipe, the pipe support structure having a generally triangularly shaped extension formed integral with and extending circumferentially around its outward side, the bottom side of this extension generally forming a ledge; an annular load-bearing insulation formed adjacent to the extension; means for clamping the load-bearing insulation to extension; and means for providing constant vertical support to means for clamping [fr

Seismic ratchet-fatigue failure of piping systems

International Nuclear Information System (INIS)

Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Weiner, E.O.

1987-01-01

Failures of piping systems during earthquakes have been rare. Those that have failed were either made of brittle material such as cast iron, were rigid systems between major components where component relative seismic motions tore the pipe out of the component, or were high pressure systems where a ratchet-fatigue fracture followed a local bulging of the pipe diameter. Tests to failure of an unpressurized 3-inch and a pressurized 6-inch diameter carbon steel nuclear pipe systems subjected to high-level shaking have been accomplished. The high-level shaking loads needed to cause failure were much higher than ASME Code rules would permit with present design limits. Failure analyses of these tests are presented and correlated to the test results. It was found that failure of the unpressurized system could be correlated well with standard ASME type fatigue analysis predictions. Moreover, the pressurized system failure occured in significantly less load cycles than predicted by standard fatigue analysis. However, a ratchet-fatigue and ductility exhaustion analysis of the pressurized system did correlate reasonably well. These findings indicate modifications to design analysis methods and the present ASME Code piping design rules to reduce unneeded conservatisms and to cover the ratchet-fatigue failure mode may be appropriate

Augmented of turbulent heat transfer in an annular pipe with abrupt expansion

Directory of Open Access Journals (Sweden)

Togun Hussein

2016-01-01

Full Text Available This paper presents a study of heat transfer to turbulent air flow in the abrupt axisymmetric expansion of an annular pipe. The experimental investigations were performed in the Reynolds number range from 5000 to 30000, the heat flux varied from 1000 to 4000 W/m2, and the expansion ratio was maintained at D/d=1, 1.25, 1.67 and 2. The sudden expansion was created by changing the inner diameter of the entrance pipe to an annular passage. The outer diameter of the inner pipe and the inner diameter of the outer pipe are 2.5 and 10 cm, respectively, where both of the pipes are subjected to uniform heat flux. The distribution of the surface temperature of the test pipe and the local Nusselt number are presented in this investigation. Due to sudden expansion in the cross section of the annular pipe, a separation flow was created, which enhanced the heat transfer. The reduction of the surface temperature on the outer and inner pipes increased with the increase of the expansion ratio and the Reynolds number, and increased with the decrease of the heat flux to the annular pipe. The peak of the local Nusselt number was between 1.64 and 1.7 of the outer and inner pipes for Reynolds numbers varied from 5000 to 30000, and the increase of the local Nusselt number represented the augmentation of the heat transfer rate in the sudden expansion of the annular pipe. This research also showed a maximum heat transfer enhancement of 63-78% for the outer and inner pipes at an expansion ratio of D/d=2 at a Re=30000 and a heat flux of 4000W/m2.

Performance correlations for high temperature potassium heat pipes

International Nuclear Information System (INIS)

Merrigan, M.A.; Keddy, E.S.; Sena, J.T.

1987-01-01

Potassium heat pipes designed for operation at a nominal temperature of 775K have been developed for use in a heat pipe cooled reactor design. The heat pipes operate in a gravity assist mode with a maximum required power throughput of approximately 16 kW per heat pipe. Based on a series of sub-scale experiments with 2.12 and 3.2 cm diameter heat pipes the prototypic heat pipe diameter was set at 5.7 cm with a simple knurled wall wick used in the interests of mechanical simplicity. The performance levels required for this design had been demonstrated in prior work with gutter assisted wicks and emphasis in the present work was on the attainment of similar performance with a simplified wick structure. The wick structure used in the experiment consisted of a pattern of knurled grooves in the internal wall of the heat pipe. The knurl depth required for the planned heat pipe performance was determined by scaling of wick characteristic data from the sub-scale tests. These tests indicated that the maximum performance limits of the test heat pipes did not follow normal entrainment limit predictions for textured wall gravity assist heat pipes. Test data was therefore scaled to the prototype design based on the assumption that the performance was controlled by an entrainment parameter based on the liquid flow depth in the groove structure. This correlation provided a reasonable fit to the sub-scale test data and was used in scale up of the design from the 8.0 cm 2 cross section of the largest sub-scale heat pipe to the 25.5 cm 2 cross section prototype. Correlation of the model predictions with test data from the prototype is discussed

Internal testing of pipe systems with IRIS inspection system

International Nuclear Information System (INIS)

1986-01-01

The internal piping inspection system IRIS allows inside testing of pipes with an internal diameter of NW 70 as a minimum, and of any horizontal or vertical layout of the piping system. Visual testing is done by means of an integrated CCD video system with high resolution power. Technical data are given and examples of applications, in the German and English language. (DG) [de

Forensic characterization of HDPE pipes by DSC.

Science.gov (United States)

Sajwan, Madhuri; Aggarwal, Saroj; Singh, R B

2008-03-05

The melting behavior of 28 high density polyethylene (HDPE) pipe samples manufactured and supplied by 13 different manufacturers in India was examined by 'differential scanning calorimetry (DSC)' to find out if this parameter could be used in differentiating between these HDPE pipe samples which are chemically the same and being manufactured by different manufacturer. The results indicate that the melting temperature may serve as the useful criteria for differentiating HDPE (i) pipe samples from different sources and (ii) samples of different diameter from the same source.

Characterization of radioactive contamination inside pipes with the Pipe Explorer trademark system

International Nuclear Information System (INIS)

Kendrick, D.T.; Cremer, C.D.; Lowry, W.; Cramer, E.

1995-01-01

The U.S. Department of Energy's nuclear facility decommissioning program needs to characterize radiological contamination inside piping systems before the pipe can be recycled, remediated, or disposed. Science and Engineering associates, Inc. under contract with the DOE Morgantown Energy Technology Center has developed and demonstrated the Pipe Explorer trademark system, which uses an inverting membrane to transport various characterization sensors into pipes. The basic process involves inverting (turning inside out) a tubular impermeable membrane under air pressure. A characterization sensor is towed down the interior of the pipe by the membrane. Advantages of this approach include the capability of deploying through constrictions in the pipe, around 90 degrees bends, vertically up and down, and in slippery conditions. Because the detector is transported inside the membrane (which is inexpensive and disposable), it is protected from contamination, which eliminates cross-contamination. Characterization sensors that have been demonstrated with the system thus far include: gamma detectors, beta detectors, video cameras, and pipe locators. Alpha measurement capability is currently under development. A remotely operable Pipe Explorer trademark system has been developed and demonstrated for use in DOE facilities in the decommissioning stage. The system is capable of deployment in pipes as small as 2-inch-diameter and up to 250 feet long. This paper describes the technology and presents measurement results of a field demonstration conducted with the Pipe Explorer trademark system at a DOE site. These measurements identify surface activity levels of U-238 contamination as a function of location in drain lines. Cost savings to the DOE of approximately $1.5 million dollars were realized from this one demonstration

Resolution of thermal striping issue downstream of a horizontal pipe elbow in stratified pipe flow

International Nuclear Information System (INIS)

Kuzay, T.M.; Kasza, K.E.

1985-01-01

A thermally stratified pipe flow produced by a thermal transient when passing through a horizontal elbow as a result of secondary flow gives rise to large thermal fluctuations on the inner curvature wall of the downstream piping. These fluctuations were measured in a specially instrumented horizontal pipe and elbow system on a test set-up using water in the Mixing Components Technology Facility (MCTF) at Argonne National Laboratory (ANL). This study is part of a larger program which is studying the influence of thermal buoyancy on general reactor component performance. This paper discusses the influence of pipe flow generated thermal oscillations on the thermal stresses induced in the pipe walls. The instrumentation was concentrated around the exit plane of the 90 0 sweep elbow, since prior tests had indicated that the largest thermal fluctuations would occur within about one hydraulic diameter downstream of the elbow exit. The thermocouples were located along the inner curvature of the piping and measured the near surface fluid temperature. The test matrix involved thermal downramps under turbulent flow conditions

Dosimetric evaluation of multi-sided irradiation on HDPE pipes under 2 MeV electron beam

Energy Technology Data Exchange (ETDEWEB)

Benny, P.G., E-mail: bennypg@yahoo.com; Khader, S.A.; Sarma, K.S.S.

2014-03-01

The use of electron beam technology has enabled the production of heat resistant pipe for hot water circulation. One of the difficulties in the irradiation of pipe products is the uneven penetration of electrons. Quality of the radiation process depends on radiation dose and homogeneity of the dose distribution, which becomes a major concern when treatments of circular objects like pipes are performed. One method to achieve uniformity in the absorbed dose in the product is to use multi-sided irradiation. The paper discusses the importance of dosimetry mapping in industrial electron beam radiation processing and outlines the challenges in delivering a uniform dose to cylindrical objects. In this study, HDPE pipe of 5 mm thickness of homogeneous material (40 mm outer diameter and 30 mm inner diameter) has been chosen for multi-sided irradiation under 2 MeV scanned electron beam from the ILU-6 accelerator. - Highlights: • The paper outlines the challenges in delivering uniform dose to cylindrical objects at 2 MeV industrial electron beam facility. • HDPE pipe of 40 mm outer diameter and 30 mm inner diameter has been chosen for the study. • The circumferential dose distribution inside and outside of the pipes were evaluated by using calibrated CTA dosimeter strips. • Using stack of dosimeter strips, changes in circumferential dose distribution in the annular region of the pipe was evaluated. • Optimization of multi-sided irradiation on the HDPE pipes for better dose homogeneity is reported in the paper.

Dosimetric evaluation of multi-sided irradiation on HDPE pipes under 2 MeV electron beam

International Nuclear Information System (INIS)

Benny, P.G.; Khader, S.A.; Sarma, K.S.S.

2014-01-01

The use of electron beam technology has enabled the production of heat resistant pipe for hot water circulation. One of the difficulties in the irradiation of pipe products is the uneven penetration of electrons. Quality of the radiation process depends on radiation dose and homogeneity of the dose distribution, which becomes a major concern when treatments of circular objects like pipes are performed. One method to achieve uniformity in the absorbed dose in the product is to use multi-sided irradiation. The paper discusses the importance of dosimetry mapping in industrial electron beam radiation processing and outlines the challenges in delivering a uniform dose to cylindrical objects. In this study, HDPE pipe of 5 mm thickness of homogeneous material (40 mm outer diameter and 30 mm inner diameter) has been chosen for multi-sided irradiation under 2 MeV scanned electron beam from the ILU-6 accelerator. - Highlights: • The paper outlines the challenges in delivering uniform dose to cylindrical objects at 2 MeV industrial electron beam facility. • HDPE pipe of 40 mm outer diameter and 30 mm inner diameter has been chosen for the study. • The circumferential dose distribution inside and outside of the pipes were evaluated by using calibrated CTA dosimeter strips. • Using stack of dosimeter strips, changes in circumferential dose distribution in the annular region of the pipe was evaluated. • Optimization of multi-sided irradiation on the HDPE pipes for better dose homogeneity is reported in the paper

Wat betekent ‘Seamless learning’ (voor u)?

NARCIS (Netherlands)

Rusman, Ellen

2017-01-01

Wat betekent Seamless Learning (voor u)? ‘Seamless learning’ richt zich op het doormiddel van technologie draadloos en naadloos verbinden van (leer)ervaringen in verschillende contexten en het hierdoor ondersteunen, verbeteren en versterken van leerprocessen. ‘Seamless’ leerscenario’s bieden

Costs reduced by innovative plastic distribution pipe use

International Nuclear Information System (INIS)

Maxwell, F.W.

1995-01-01

As part of a strategic corporate cost-reduction initiative, Pacific Gas and Electric Company's Gas Distribution Group has achieved some quick but significant cash savings. System design, construction, and the purchasing function were areas that produced some fast paybacks while maintaining reliability and safety. The primary savings were made by optimizing pipe specifications to match system operating parameters. This allowed the use of smaller diameter pipes and/or thinner wall pipes which conserved the materials cost of the pipeline. Other realized savings in the form of coiled pipe, purchasing changes, and backfilling specifications are also described

Innovative technology summary report: High-speed clamshell pipe cutter

International Nuclear Information System (INIS)

1998-09-01

The Hanford Site C Reactor Technology Demonstration Group demonstrated the High-Speed Clamshell Pipe Cutter technology, developed and marketed by Tri Tool Inc. (Rancho Cordova, California). The models demonstrated are portable, split-frame pipe lathes that require minimal radial and axial clearances for severing and/or beveling in-line pipe with ranges of 25 cm to 41 cm and 46 cm to 61 cm nominal diameter. The radial clearance requirement from the walls, floors, or adjacent pipes is 18 cm. The lathes were supplied with carbide insert conversion kits for the cutting bits for the high-speed technique that was demonstrated. Given site-specific factors, this demonstration showed the cost of the improved technology to be approximately 30% higher than the traditional (baseline) technology (oxyacetylene torch) cost of $14,400 for 10 cuts of contaminated 41-cm and 61-cm-diameter pipe at C Reactor. Actual cutting times were faster than the baseline technology; however, moving/staging the equipment took longer. Unlike the baseline torch, clamshell lathes do not involve applied heat, flames, or smoke and can be operated remotely, thereby helping personal exposures to be as low as reasonably achievable. The baseline technology was demonstrated at the C Reactor north and south water pipe tunnels August 19--22, 1997. The improved technology was demonstrated in the gas pipe tunnel December 15--19

Clogging of granular material in vertical pipes discharged at constant velocity

Directory of Open Access Journals (Sweden)

López-Rodríguez Diego

2017-01-01

Full Text Available We report an experimental study on the flow of spherical particles through a vertical pipe discharged at constant velocity by means of a conveyor belt placed at the bottom. For a pipe diameter 3.67 times the diameter of the particles, we observe the development of hanging arches that stop the flow as they are able to support the weight of the particles above them. We find that the distribution of times that it takes until a stable clog develops, decays exponentially. This is compatible with a clogging probability that remains constant during the discharge. We also observe that the probability of clogging along the pipe decreases with the height, i.e. most of the clogs are developed near the bottom. This spatial dependence may be attributed to different pressure values within the pipe which might also be related to a spontaneous development of an helical structure of the grains inside the pipe.

Resolution of thermal striping issue downstream of a horizontal pipe elbow in stratified pipe flow. [LMFBR

Energy Technology Data Exchange (ETDEWEB)

Kuzay, T.M.; Kasza, K.E.

1985-01-01

A thermally stratified pipe flow produced by a thermal transient when passing through a horizontal elbow as a result of secondary flow gives rise to large thermal fluctuations on the inner curvature wall of the downstream piping. These fluctuations were measured in a specially instrumented horizontal pipe and elbow system on a test set-up using water in the Mixing Components Technology Facility (MCTF) at Argonne National Laboratory (ANL). This study is part of a larger program which is studying the influence of thermal buoyancy on general reactor component performance. This paper discusses the influence of pipe flow generated thermal oscillations on the thermal stresses induced in the pipe walls. The instrumentation was concentrated around the exit plane of the 90/sup 0/ sweep elbow, since prior tests had indicated that the largest thermal fluctuations would occur within about one hydraulic diameter downstream of the elbow exit. The thermocouples were located along the inner curvature of the piping and measured the near surface fluid temperature. The test matrix involved thermal downramps under turbulent flow conditions.

Modeling benzene permeation through drinking water high density polyethylene (HDPE) pipes.

Science.gov (United States)

Mao, Feng; Ong, Say Kee; Gaunt, James A

2015-09-01

Organic compounds such as benzene, toluene, ethyl benzene and o-, m-, and p-xylene from contaminated soil and groundwater may permeate through thermoplastic pipes which are used for the conveyance of drinking water in water distribution systems. In this study, permeation parameters of benzene in 25 mm (1 inch) standard inside dimension ratio (SIDR) 9 high density polyethylene (HDPE) pipes were estimated by fitting the measured data to a permeation model based on a combination of equilibrium partitioning and Fick's diffusion. For bulk concentrations between 6.0 and 67.5 mg/L in soil pore water, the concentration-dependent diffusion coefficients of benzene were found to range from 2.0×10(-9) to 2.8×10(-9) cm2/s while the solubility coefficient was determined to be 23.7. The simulated permeation curves of benzene for SIDR 9 and SIDR 7 series of HDPE pipes indicated that small diameter pipes were more vulnerable to permeation of benzene than large diameter pipes, and the breakthrough of benzene into the HDPE pipe was retarded and the corresponding permeation flux decreased with an increase of the pipe thickness. HDPE pipes exposed to an instantaneous plume exhibited distinguishable permeation characteristics from those exposed to a continuous source with a constant input. The properties of aquifer such as dispersion coefficients (DL) also influenced the permeation behavior of benzene through HDPE pipes.

Elastic-plastic fracture analysis of carbon steel piping using the latest CEGB R6 approach

International Nuclear Information System (INIS)

Kanno, S.; Hasegawa, K.; Shimizu, T.; Kobayashi, H.

1991-01-01

The elastic-plastic fracture of carbon steel piping having various pipe diameters and circumferential crack angles and subjected to a bending moment is analyzed using the latest United Kingdom Central Electricity Generating Board R6 approach. The elastic-plastic fracture criterion must be applied instead of the plastic collapse criterion with increase of the pipe diameter and the crack angle. A simplified elastic-plastic fracture analysis procedure based on the R6 approach is proposed. (author)

Social Media and Seamless Learning: Lessons Learned

Science.gov (United States)

Panke, Stefanie; Kohls, Christian; Gaiser, Birgit

2017-01-01

The paper discusses best practice approaches and metrics for evaluation that support seamless learning with social media. We draw upon the theoretical frameworks of social learning theory, transfer learning (bricolage), and educational design patterns to elaborate upon different ideas for ways in which social media can support seamless learning.…

A small diameter, flexible, all attitude, self-contained germanium spectrometer. Operator's manual

International Nuclear Information System (INIS)

Bordzindki, R.L.; Lepel, E.A.; Reeves, J.H.; Kohli, R.

1997-05-01

The end of the Cold War has brought about tremendous changes in the nuclear complex of the Department of Energy. One of the many changes has been the shutdown or decommissioning of many facilities that performed nuclear work. One of the steps in the process of decommissioning a facility involves the decontamination or removal of drain lines or pipes that may have carried radioactive materials at one time. The removal of all these pipes and drain lines to a nuclear disposal facility could be quite costly. It was suggested by Pacific Northwest National Laboratory (PNNL) that a germanium spectrometer could be built that could fit through straight pipes with a diameter as small as 5.08 cm (2 inches) and pass through curved pipes with a diameter as small as 7.6 cm (3 inches) such as that of a 3-inch p-trap in a drain line. The germanium spectrometer could then be used to simultaneously determine all gamma-ray emitting radionuclides in or surrounding the pipe. By showing the absence of any gamma-ray emitting radionuclides, the pipes could then be reused in place or disposed of as non-radioactive material, thus saving significantly in disposal costs. A germanium spectrometer system has been designed by PNNL and fabricated by Princeton Gamma Tech (PGT) that consists of three segments, each 4.84 cm in diameter and about 10 cm in length. Flexible stainless steel bellows were used to connect the segments. Segment 1 is a small liquid nitrogen reservoir. The reservoir is filled with a sponge-like material which enables the detector to be used in any orientation. A Stirling cycle refrigerator is under development which can replace the liquid nitrogen reservoir to provide continuous cooling and operation

Pipe crawler with extendable legs

International Nuclear Information System (INIS)

Zollinger, W.T.

1992-01-01

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs

Pipe crawler with extendable legs

Science.gov (United States)

Zollinger, W.T.

1992-06-16

A pipe crawler for moving through a pipe in inchworm fashion having front and rear leg assemblies separated by air cylinders to increase and decrease the spacing between assemblies. Each leg of the four legs of an assembly is moved between a wall-engaging, extended position and a retracted position by a separate air cylinder. The air cylinders of the leg assemblies are preferably arranged in pairs of oppositely directed cylinders with no pair lying in the same axial plane as another pair. Therefore, the cylinders can be as long as a leg assembly is wide and the crawler can crawl through sections of pipes where the diameter is twice that of other sections. The crawler carries a valving system, a manifold to distribute air supplied by a single umbilical air hose to the various air cylinders in a sequence controlled electrically by a controller. The crawler also utilizes a rolling mechanism, casters in this case, to reduce friction between the crawler and pipe wall thereby further extending the range of the pipe crawler. 8 figs.

40 CFR Table 25 to Subpart G of... - Effective Column Diameter (Fc)

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Effective Column Diameter (Fc) 25 Table..., Table 25 Table 25 to Subpart G of Part 63—Effective Column Diameter (Fc) Column type Fc (feet) 9-inch by 7-inch built-up columns 1.1 8-inch-diameter pipe columns 0.7 No construction details known 1.0 ...

Pipe inspection using the BTX-II. Innovative technology summary report

International Nuclear Information System (INIS)

1999-05-01

The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned

Pipe inspection using the BTX-II. Innovative technology summary report

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

Short cracks in piping and piping welds. Seventh program report, March 1993-December 1994. Volume 4, Number 1

Energy Technology Data Exchange (ETDEWEB)

Wilkowski, G.M.; Ghadiali, N.; Rudland, D.; Krishnaswamy, P.; Rahman, S.; Scott, P. [Battelle, Columbus, OH (United States)

1995-04-01

This is the seventh progress report of the U.S. Nuclear Regulatory Commission`s research program entitled {open_quotes}Short Cracks in Piping and Piping Welds{close_quotes}. The program objective is to verify and improve fracture analyses for circumferentially cracked large-diameter nuclear piping with crack sizes typically used in leak-before-break (LBB) analyses and in-service flaw evaluations. All work in the eight technical tasks have been completed. Ten topical reports are scheduled to be published. Progress only during the reporting period, March 1993 - December 1994, not covered in the topical reports is presented in this report. Details about the following efforts are covered in this report: (1) Improvements to the two computer programs NRCPIPE and NRCPIPES to assess the failure behavior of circumferential through-wall and surface-cracked pipe, respectively; (2) Pipe material property database PIFRAC; (3) Circumferentially cracked pipe database CIRCUMCK.WKI; (4) An assessment of the proposed ASME Section III design stress rule changes on pipe flaw tolerance; and (5) A pipe fracture experiment on a section of pipe removed from service degraded by microbiologically induced corrosion (MIC) which contained a girth weld crack. Progress in the other tasks is not repeated here as it has been covered in great detail in the topical reports.

Short cracks in piping and piping welds. Seventh program report, March 1993-December 1994. Volume 4, Number 1

International Nuclear Information System (INIS)

Wilkowski, G.M.; Ghadiali, N.; Rudland, D.; Krishnaswamy, P.; Rahman, S.; Scott, P.

1995-04-01

This is the seventh progress report of the U.S. Nuclear Regulatory Commission's research program entitled open-quotes Short Cracks in Piping and Piping Weldsclose quotes. The program objective is to verify and improve fracture analyses for circumferentially cracked large-diameter nuclear piping with crack sizes typically used in leak-before-break (LBB) analyses and in-service flaw evaluations. All work in the eight technical tasks have been completed. Ten topical reports are scheduled to be published. Progress only during the reporting period, March 1993 - December 1994, not covered in the topical reports is presented in this report. Details about the following efforts are covered in this report: (1) Improvements to the two computer programs NRCPIPE and NRCPIPES to assess the failure behavior of circumferential through-wall and surface-cracked pipe, respectively; (2) Pipe material property database PIFRAC; (3) Circumferentially cracked pipe database CIRCUMCK.WKI; (4) An assessment of the proposed ASME Section III design stress rule changes on pipe flaw tolerance; and (5) A pipe fracture experiment on a section of pipe removed from service degraded by microbiologically induced corrosion (MIC) which contained a girth weld crack. Progress in the other tasks is not repeated here as it has been covered in great detail in the topical reports

Inclusion of tank configurations as a variable in the cost optimization of branched piped-water networks

Science.gov (United States)

Hooda, Nikhil; Damani, Om

2017-06-01

The classic problem of the capital cost optimization of branched piped networks consists of choosing pipe diameters for each pipe in the network from a discrete set of commercially available pipe diameters. Each pipe in the network can consist of multiple segments of differing diameters. Water networks also consist of intermediate tanks that act as buffers between incoming flow from the primary source and the outgoing flow to the demand nodes. The network from the primary source to the tanks is called the primary network, and the network from the tanks to the demand nodes is called the secondary network. During the design stage, the primary and secondary networks are optimized separately, with the tanks acting as demand nodes for the primary network. Typically the choice of tank locations, their elevations, and the set of demand nodes to be served by different tanks is manually made in an ad hoc fashion before any optimization is done. It is desirable therefore to include this tank configuration choice in the cost optimization process itself. In this work, we explain why the choice of tank configuration is important to the design of a network and describe an integer linear program model that integrates the tank configuration to the standard pipe diameter selection problem. In order to aid the designers of piped-water networks, the improved cost optimization formulation is incorporated into our existing network design system called JalTantra.

The impact analysis of the connecting pipe length and diameter on the operation of a piston hybrid power machine of positive displacement with gas suction capacity

Science.gov (United States)

Shcherba, V. E.; Grigoriev, A. V.; Averyanov, G. S.; Surikov, V. I.; Vedruchenko, V. P.; Galdin, N. S.; Trukhanova, D. A.

2017-08-01

The article analyzes the impact of the connecting liquid pipe length and diameter on consumables and power characteristics of the piston hybrid power machine with gas suction capacity. The following operating characteristics of the machine were constructed and analyzed: the average height of the liquid column in the jacket space; instantaneous velocity and height of the liquid column in the jacket space; the relative height of the liquid column in the jacket space; volumetric efficiency; indicator isothermal efficiency; flowrate in the pump section; relative pressure losses during suction; relative flowrate. The dependence of the instantaneous pressure in the work space and the suction space of the compressor section on the rotation angle of the crankshaft is determined for different values of the length and diameter of the connecting pipeline.

Prediction of three-dimensional residual stresses at localised indentations in pipes

International Nuclear Information System (INIS)

Hyde, T.H.; Luo, R.; Becker, A.A.

2012-01-01

Residual stresses are investigated using Finite Element (FE) analyses at localised indentations in pipes with and without internal pressures due to reverse plasticity caused by springback of the surrounding material after removal of the indenter. The indentation loading is applied via rigid 3D short indenters. The effects of the residual indentation depth, internal pressure, indenter size and different material properties on the residual stresses for different pipes have been investigated by carrying out parametric sensitivity studies. In order to predict the residual stresses, empirical formulations have been developed, which show a good correlation with the FE for residual stresses for pipes with diameter to thickness ratios of 35–72. - Highlights: ► A comprehensive elastic–plastic FE analysis of residual stresses caused by localised pipe indentations is presented. ► The effects of residual indentation depth, internal pressure, indenter size and material properties have been studied. ► Empirical formulations have been developed, which show a good correlation with the FE for residual stresses for pipes with diameter to thickness ratios of 35–72.

LABORATORY EVALUATION ON PERFORMANCE OF GLASS FIBER REINFORCED PLASTIC MORTAR PIPE CULVERTS

OpenAIRE

Huawang Shi; Lianyu Wei

2018-01-01

This paper investigated the performance and behaviour of glass fiber reinforced plastic mortar (FRPM) pipes under different loading conditions. FRPM pipes with inner diameter of 1500 mm were prefabricated in factory. Mechanics performance testing (ring and axial compressive strength and elastic modulus), stiffness and fatigue test were carried out in laboratory. Ring stiffness test provided pipe stiffness (PS) which is a function of geometry and material type of pipe through parallel plate lo...

Ultrasonic guided waves in eccentric annular pipes

International Nuclear Information System (INIS)

Pattanayak, Roson Kumar; Balasubramaniam, Krishnan; Rajagopal, Prabhu

2014-01-01

This paper studies the feasibility of using ultrasonic guided waves to rapidly inspect tubes and pipes for possible eccentricity. While guided waves are well established in the long range inspection of structures such as pipes and plates, studies for more complex cross sections are limited and analytical solutions are often difficult to obtain. Recent developments have made the Semi Analytical Finite Element (SAFE) method widely accessible for researchers to study guided wave properties in complex structures. Here the SAFE method is used to study the effect of eccentricity on the modal structures and velocities of lower order guided wave modes in thin pipes of diameters typically of interest to the industry. Results are validated using experiments. The paper demonstrates that even a small eccentricity in the pipe can strongly affect guided wave mode structures and velocities and hence shows potential for pipe eccentricity inspection

Experimental investigation of coarse particle conveying in pipes

Directory of Open Access Journals (Sweden)

Vlasak Pavel

2015-01-01

Full Text Available The advanced knowledge of particle-water mixture flow behaviour is important for safe, reliable, and economical design and operation of the freight pipelines. The effect of the mixture velocity and concentration on the coarse particle – water mixtures flow behaviour was experimentally investigated on an experimental pipe loop of inner diameter D = 100 mm with horizontal, vertical, and inclined pipe sections. Narrow particle size distribution basalt pebbles were used as model of coarse-grained solid particles. The radiometric method was used to measure particle concentration distribution in pipe cross-section. Mixture flow behaviour and particles motion along the pipe invert were studied in a pipe viewing section. The study revealed that the coarse particlewater mixtures in the horizontal and inclined pipe sections were significantly stratified. The particles moved principally in a layer close to the pipe invert. However, for higher and moderate flow velocities the particles moved also in the central part of the pipe cross-section, and particle saltation was found to be dominant mode of particle conveying.

Seamless integrated network system for wireless communication systems

NARCIS (Netherlands)

Wu, Gang; Mizuno, Mitsuhiko; Hase, Yoshihiro; Havinga, Paul J.M.

2006-01-01

To create a network that connects a plurality of wireless communication systems to create optimal systems for various environments, and that seamlessly integrates the resulting systems together in order to provide more efficient and advanced service in general. A network system that can seamlessly

Seamless integrated network system for wireless communication systems

NARCIS (Netherlands)

Wu, Gang; Mizuno, Mitsuhiko; Hase, Yoshihiro; Havinga, Paul J.M.

2002-01-01

To create a network that connects a plurality of wireless communication systems to create optimal systems for various environments, and that seamlessly integrates the resulting systems together in order to provide more efficient and advanced service in general. A network system that can seamlessly

Flow structure in a downward branch pipe with a closed end. Characteristics of flow velocity in the branch pipe

International Nuclear Information System (INIS)

Miyoshi, Koji; Nakamura, Akira; Takenaka, Nobuyuki

2016-01-01

Many pipes branch off from a main pipe in industrial plants. The penetration of hot water into the branch pipe causes thermal stratification. The thermal stratification layer fluctuates and causes thermal fatigue. The characteristics of velocity distributions in the branch pipe for inner diameters from D_b=21 mm to 43 mm were investigated by laser Doppler velocimetry in this paper. As for the flow in the branch pipe at L=4D_b, the mean velocity of the spiral flow was a simple forced vortex which indicated a straight velocity distribution. The maximum circumferential velocity U_θ _m_a_x and minimum axial velocity U_z _m_i_n at L=4D_b were expressed with D_b and main flow velocity. Empirical formulas were proposed for estimating the distributions of U_θ _m_a_x and U_z _m_i_n in the axial direction. (author)

Pipe crawlers: Versatile adaptations for real applications

International Nuclear Information System (INIS)

Hapstack, M.; Talarek, T.R.

1990-01-01

A problem at the Savannah River Site requires the unique application of a pipe crawler. A number of stainless steel pipes buried in concrete require ultrasonic inspection of the heat affected zones of the welds for detection of flaws or cracks. The paper describes the utilization of an inch-worm motion pipe crawler which negotiates a 90 degree reducing elbow with significant changes in diameter and vertical sections before entering the area of concern. After a discussion of general considerations and problem description, special requirements to meet the objectives and the design approach regarding the tractor, control system, instrument carriage, and radiation protection are discussed. 2 refs., 11 figs. (MB)

Study of near-source earthquake effects on flexible buried pipes

Science.gov (United States)

Davis, Craig Alan

2000-10-01

An investigation is carried out, using strong ground motion recordings, field measurements, and new analytical models, on large diameter flexible buried pipes shaken in the 1994 Northridge earthquake near field. Case studies are presented for corrugated metal pipes (CMP) in the Van Norman Complex (VNC) vicinity in Los Angeles, California. In 1994 the VNC yielded an unprecedented number of strong motion recordings with high acceleration and velocity. These recordings contain forward directivity pulses and provided the largest velocity ever instrumentally recorded (180 cm/s). The recorded motions were significantly different in the longitudinal and transverse directions and had approximately half the amplitude at the VNC center than on the north and south ends. The seismic performances of 61 underground CMPs are presented, beginning with detailed studies of a 2.4 m diameter pipe that suffered complete lateral buckling collapse at the Lower San Fernando Dam (LSFD). The case histories identify factors controlling large diameter CMP seismic performances that are incorporated into several newly developed models for the analysis and design of buried structures. Each model progressively improves the understanding of buried pipe behavior. Simple acceleration- and strain-based pseudo-static models are initially developed to identify main causes for CMP damage. Elasto-dynamic models for transverse SV waves are later used to understand flexible pipe response in the frequency and time domains and are compared with existing solutions. Finally, pseudo-static models, which analyze pipe responses in terms of free-field strains, are formulated to account for dynamic amplification, non-vertical wave incidence, soil layering, and trench backfill soil stiffness. The elastic models are used to investigate soil-pipe interface shear stress and non-linear soil behavior and show that the maximum pipe hoop force is best characterized by assuming no interface slippage. The models explain the

Problems of cleaning the large diameter sections of deep wells

Energy Technology Data Exchange (ETDEWEB)

Patsch, F; Gilicz, B

1966-01-01

In drilling deep wells, great importance is being given to the problem of cutting removal from the hole bottom of sections drilled by large diameter bits. The length of borehole sections drilled by 12-1/4-in. and larger bits has been more than doubled in Hungary in the course of the past 4 years. When the drilling fluid jet is struck against the borehole bottom, pressure waves are brought about which take on a crossed flow pattern and result in a retardation of cleaning of the well bottom, particularly in the case of larger bottom surfaces. In large diameter boreholes, the cleaning efficiency is being achieved by full utilization of the pump power and increased pump delivery. Friction losses in drill pipes are being reduced by using 6-in. XH pipes.

BOA II: pipe-asbestos insulation removal system

International Nuclear Information System (INIS)

Schempf, H.; Mutschler; Boehmke, S.; Chemel, B.; Piepgras, C.

1996-01-01

BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to high labor costs and high level of radioactive contamination, making manual removal costly and inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee

Evaluation of stress corrosion crack growth in BWR piping systems

International Nuclear Information System (INIS)

Kassir, M.; Sharma, S.; Reich, M.; Chang, M.T.

1985-05-01

This report presents the results of a study conducted to evaluate the effects of stress intensity factor and environment on the growth behavior of intergranular stress corrosion cracks in type 304 stainless steel piping systems. Most of the detected cracks are known to be circumferential in shape, and initially started at the inside surface in the heat affected zone near girth welds. These cracks grow both radially in-depth and circumferentially in length and, in extreme cases, may cause leakage in the installation. The propagation of the crack is essentially due to the influence of the following simultaneous factors: (1) the action of applied and residual stress; (2) sensitization of the base metal in the heat affected zone adjacent to girth weld; and (3) the continuous exposure of the material to an aggressive environment of high temperature water containing dissolved oxygen and some levels of impurities. Each of these factors and their effects on the piping systems is discussed in detail in the report. The report also evaluates the time required for hypothetical cracks in BWR pipes to propagate to their critical size. The pertinent times are computed and displayed graphically. Finally, parametric study is performed in order to assess the relative influence and sensitivity of the various input parameters (residual stress, crack growth law, diameter of pipe, initial size of defect, etc.) which have bearing on the growth behavior of the intergranular stress corrosion cracks in type 304 stainless steel. Cracks in large-diameter as well as in small-diameter pipes are considered and analyzed. 27 refs., 25 figs., 10 tabs

The IPIRG-1 pipe system fracture tests: Experimental results

International Nuclear Information System (INIS)

Scott, P.; Olson, R.J.; Wilkowski, G.M.

1994-01-01

As part of the First International Piping Integrity Research Group (IPIRG-1) program, six dynamic pipe system experiments were conducted. The objective of these experiments was to generate experimental data to assess analysis methodologies for characterizing the fracture behavior of circumferentially cracked pipe in a representative piping system subjected to combined inertial and displacement-controlled stresses. A unique experimental facility was designed and constructed. The pipe system evaluated was an expansion loop with over 30 m (100 feet) of 16-inch nominal diameter Schedule 100 pipe. The experimental facility was equipped with special hardware to ensure that system boundary conditions could be appropriately modeled. The test matrix involved one uncracked and five cracked dynamic pipe system experiments. The uncracked-pipe experiment was conducted to evaluate the piping system damping and natural frequency characteristics. The cracked-pipe experiments were conducted to evaluate the fracture behavior, piping system response, and fracture stability characteristics of five different materials. All cracked-pipe experiments were conducted at PWR conditions. Material characterization efforts provided the tensile and fracture toughness properties of the different pipe materials at various strain rates and temperatures. Key results from the six pipe system experiments and material characterization efforts are presented. Detailed analyses will be published in a companion paper

Development of piping strain sensor for stress evaluation

International Nuclear Information System (INIS)

Takahama, Tsunemichi; Nishimura, Kazuma; Ninomiya, Seiichiro; Matsumoto, Yoshihiro; Harada, Yutaka

2014-01-01

In a small diameter piping, stresses are generated due to internal fluid or pump vibrations especially around the welding parts. Authors have successfully developed a pipe strain sensor which is able to measure such stresses. Unlike conventional methods using strain gages and adhesive bond, the sensor can measure the strain without putting adhesive bond on the piping surface. However, the strain sensor can provide measurements with a level of accuracy equivalent to that of conventional method using strain gages and adhesive bond. Accordingly, the strain sensor can significantly reduce the working time without any loss of the measurement accuracy. (author)

Unsteady hydraulic characteristics in pipe with elbow under high Reynolds condition

Energy Technology Data Exchange (ETDEWEB)

Ono, A.; Kimura, N.; Kamide, H.; Tobita, A. [Japan Atomic Energy Agency, O-arai, Ibaraki (Japan)

2011-07-01

In the design of Japan Sodium-cooled Fast Reactor (JSFR), coolant velocity is beyond 9 m/s in the primary hot leg pipe of 1.27 m diameter. The Reynolds number in the piping reaches 4.2x10{sup 7}. Moreover, a short-elbow (r/D=1.0, r: curvature radius, D: pipe diameter) is adopted in the hot leg pipe in order to achieve compact plant layout and reduce plant construction cost. Therefore, the flow-induced vibration (FIV) arising from the piping geometry may occur in the short-elbow pipe. The FIV is due to the excitation force which is caused by the pressure fluctuation on the wall. The pressure fluctuation on the pipe wall is closely related with the flow fluctuation. In this study, water experiments using two types of 1/8 scaled elbows with different curvature ratio, r/D=1.0 and 1.5 (short-elbow and long-elbow), were conducted in order to investigate the mechanism of velocity and pressure fluctuation in the elbow and its downstream. The experiments were carried out at Re=5.4x10{sup 5} conditions. Measurement of velocity fluctuation and pressure fluctuation in two types of elbows with different curvature revealed that behavior of separation region and the circumferential secondary flow affected the pressure fluctuation on the wall of the elbow greatly. (author)

Determination of optimum insulation thickness in pipe for exergetic life cycle assessment

International Nuclear Information System (INIS)

Keçebaş, Ali

2015-01-01

Highlights: • It is aimed to determine optimum insulation thickness in pipe. • A new methodology is used as exergetic life cycle assessment for this purpose. • It is evaluated for various fuels, different pipe diameters and some combustion parameters. • This methodology is not suitable for determining optimum insulation thickness of a pipe. • There are benefits to our understanding of the need for insulation use in pipes. - Abstract: The energy saving and the environmental impacts’ reduction in the world building sector have gained great importance. Therefore, great efforts have been invested to create energy-saving green buildings. To do so, one of the many things to be done is the insulation of cylindrical pipes, canals and tanks. In the current study, the main focus is on the determination of the optimum insulation thickness of the pipes with varying diameters when different fuels are used. Therefore, through a new method combining exergy analysis and life cycle assessment, optimum insulation thickness of the pipes, total exergetic environmental impact, net saving and payback period were calculated. The effects of the insulation thickness on environmental and combustion parameters were analyzed in a detailed manner. The results revealed that optimum insulation thickness was affected by the temperature of the fuel when it enters into the combustion chamber, the temperature of the stack gas and the temperature of the combustion chamber. Under these optimum effects, the optimum insulation thickness of a 100 mm pipe was determined to be 55.7 cm, 57.2 cm and 59.3 cm for coal, natural gas and fuel–oil, respectively with the ratios of 76.32%, 81.84% and 84.04% net savings in the exergetic environmental impact. As the environmental impacts of the fuels and their products are bigger than those of the insulation material, the values of the optimum insulation thickness of the method used this study was found greater. Moreover, in the pipes with greater

Dynamic pipe control with a multiple digit automatic measuring device

International Nuclear Information System (INIS)

Jenzer, P.

1984-01-01

With the flow rotating method, thin-walled pipes can be produced with very tight tolerances and high mechanical sturdiness. The measuring device permits a dynamic control of these pipes, the outer diameter of which can lie between 70 and 300 mm, the length between 500 and 2000 mm and the wall thickness between 0,5 and 10 mm. Depending on the pipe type, up to 27 measurements in a maximum of 5 measuring levels are to be controlled. (orig.) [de

BOA: Asbestos Pipe-Insulation Abatement Robot System

International Nuclear Information System (INIS)

Schempf, H.

1996-01-01

The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee

BOA: Pipe asbestos insulation removal robot system

International Nuclear Information System (INIS)

Schempf, H.; Bares, J.; Schnorr, W.

1995-01-01

The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee

BOA: Pipe-asbestos insulation removal robot system

Energy Technology Data Exchange (ETDEWEB)

Schempf, H.; Bares, J.; Schnorr, W. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1995-10-01

The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee.

BOA: Pipe-asbestos insulation removal robot system

International Nuclear Information System (INIS)

Schempf, H.; Bares, J.; Schnorr, W.

1995-01-01

The BOA system is a mobile pipe-external robotic crawler used to remotely strip and bag asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations. Steam and process lines within the DOE weapons complex warrant the use of a remote device due to the high labor costs and high level of radioactive contamination, making manual removal extremely costly and highly inefficient. Currently targeted facilities for demonstration and remediation are Fernald in Ohio and Oak Ridge in Tennessee

Detection of underground water distribution piping system and leakages using ground penetrating radar (GPR)

Science.gov (United States)

Amran, Tengku Sarah Tengku; Ismail, Mohamad Pauzi; Ahmad, Mohamad Ridzuan; Amin, Mohamad Syafiq Mohd; Sani, Suhairy; Masenwat, Noor Azreen; Ismail, Mohd Azmi; Hamid, Shu-Hazri Abdul

2017-01-01

A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

Modified distribution parameter for churn-turbulent flows in large diameter channels

Energy Technology Data Exchange (ETDEWEB)

Schlegel, J.P., E-mail: jschlege@purdue.edu; Macke, C.J.; Hibiki, T.; Ishii, M.

2013-10-15

Highlights: • Void fraction data collected in pipe sizes up to 0.304 m using impedance void meters. • Flow conditions extend to transition between churn-turbulent and annular flow. • Flow regime identification results agree with previous studies. • A new model for the distribution parameter in churn-turbulent flow is proposed. -- Abstract: Two phase flows in large diameter channels are important in a wide range of industrial applications, but especially in analysis of nuclear reactor safety for the prediction of BWR behavior and safety analysis in PWRs. To remedy an inability of current drift-flux models to accurately predict the void fraction in churn-turbulent flows in large diameter pipes, extensive experiments have been performed in pipes with diameters of 0.152 m, 0.203 m and 0.304 m to collect area-averaged void fraction data using electrical impedance void meters. The standard deviation and skewness of the impedance meter signal have been used to characterize the flow regime and confirm previous flow regime transition results. By treating churn-turbulent flow as a transition between cap-bubbly dispersed flow and annular separated flow and using a linear ramp, the distribution parameter has been modified for churn-turbulent flow. The modified distribution parameter has been evaluated through comparison of the void fraction predicted by the drift-flux model and the measured void fraction.

Modified distribution parameter for churn-turbulent flows in large diameter channels

International Nuclear Information System (INIS)

Schlegel, J.P.; Macke, C.J.; Hibiki, T.; Ishii, M.

2013-01-01

Highlights: • Void fraction data collected in pipe sizes up to 0.304 m using impedance void meters. • Flow conditions extend to transition between churn-turbulent and annular flow. • Flow regime identification results agree with previous studies. • A new model for the distribution parameter in churn-turbulent flow is proposed. -- Abstract: Two phase flows in large diameter channels are important in a wide range of industrial applications, but especially in analysis of nuclear reactor safety for the prediction of BWR behavior and safety analysis in PWRs. To remedy an inability of current drift-flux models to accurately predict the void fraction in churn-turbulent flows in large diameter pipes, extensive experiments have been performed in pipes with diameters of 0.152 m, 0.203 m and 0.304 m to collect area-averaged void fraction data using electrical impedance void meters. The standard deviation and skewness of the impedance meter signal have been used to characterize the flow regime and confirm previous flow regime transition results. By treating churn-turbulent flow as a transition between cap-bubbly dispersed flow and annular separated flow and using a linear ramp, the distribution parameter has been modified for churn-turbulent flow. The modified distribution parameter has been evaluated through comparison of the void fraction predicted by the drift-flux model and the measured void fraction

Load-deflection characteristics of small-bore insulated-pipe clamps

International Nuclear Information System (INIS)

Severud, L.K.; Clark, G.L.

1981-12-01

The special insulated clamps used on both FFTF and CRBR piping utilize a Belleville spring arrangement to compensate for pipe thermal expansion. Analysis indicates that this produces a non-linear, directionally sensitive clamp spring rate. Since these spring rates influence the seismic response of a supported piping system, it was deemed necessary to evaluate them further by test. This has been accomplished for the FFTF clamps. A more standard insulated pipe clamp, which does not incorporate Belleville springs to accommodate thermal expansion, was also tested. This type clamp is simple in design, and economically attractive. It may have wide application prospects for use in LMFBR small bore auxiliary piping operating at temperatures below 427 0 C. Load deflection tests were conducted on 2.54 CM and 7.62 CM diameter samples of these commercial clamps

Experimental basis for parameters contributing to energy dissipation in piping systems

International Nuclear Information System (INIS)

Ibanez, P.; Ware, A.G.

1985-01-01

The paper reviews several pipe testing programs to suggest the phenomena causing energy dissipation in piping systems. Such phenomena include material damping, plasticity, collision in gaps and between pipes, water dynamics, insulation straining, coupling slippage, restraints (snubbers, struts, etc.), and pipe/structure interaction. These observations are supported by a large experimental data base. Data are available from in-situ and laboratory tests (pipe diameters up to about 20 inches, response levels from milli-g's to responses causing yielding, and from excitation wave forms including sinusoid, snapback, random, and seismic). A variety of pipe configurations have been tested, including simple, bare, straight sections and complex lines with bends, snubbers, struts, and insulation. Tests have been performed with and without water and at zero to operating pressure. Both light water reactor and LMFBR piping have been tested

Design of small diameter HT/HP sour service reeled rigid pipelines

Energy Technology Data Exchange (ETDEWEB)

Carneiro, Daniel; Gouveia, Joao; Tardelli, Luciano [Tecnitas, Rio de Janeiro, RJ (Brazil)], e-mail: daniel.carneiro@br.bureauveritas.com; Parrilha, Rafael [Bureau Veritas Group, London (United Kingdom); Oazen, Eduardo; Cardoso, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2009-12-19

The paper presents an overview of the challenges overcome in the engineering design of two 219 mm diameter, 6 km length oil production pipelines, to be installed by reeling at Espirito Santo Basin, offshore Brazilian coast in 1500 m water depth. The high temperature and high pressure (HT/HP) operating conditions and sour content associated with the small diameter required to single well oil production would usually lead to flexible flow line solution in Brazilian fields. The decision of employing small diameter thick-walled rigid C-Mn steel pipelines with thick thermal insulation made necessary extensive engineering work to achieve a safe and robust thermal expansion control arrangement, including the design of walking mitigation and buckle initiation apparatus; a feasible weld acceptance criterion covering both high cycle fatigue due to pipe lay and vortex induced vibration (VIV) at free spans, and high strain low cycle fatigue and fracture growth induced by reeling installation and in-service lateral buckling. Several studies were performed using highly non-linear three-dimensional finite element models considering: pipe-soil interaction with full 3D seabed bathymetry; load history maintained from pipe lay to operational cycles, including temperature transient effects; high plastic strains (including steel properties de-rating due to high temperature) and section ovalization; mechanical contact between pipe and appurtenances during both installation and operational phases. Pipe-soil interaction comprised embedment considering dynamic effects of pipe lay and full non-linear lateral and axial response curves including break-out and residual resistance. Strain concentration factors due to field joints were evaluated using detailed solid models considering non-linear response of both steel and insulation materials. Susceptibility to VIV at free spans was assessed considering post loaded deformed span natural frequencies, including multi-span interaction effects and

Load-deflection characteristics of small bore insulated pipe clamps

International Nuclear Information System (INIS)

Severud, L.K.; Clark, G.L.

1982-01-01

High temperature LMFBR piping is subject to rapid temperature changes during transient events. Typically, this pipe is supported by specially designed insulated pipe clamps to prevent excessive thermal stress from developing during these transients. The special insulated clamps used on both FFTF and CRBR piping utilize a Belleville spring arrangement to compensate for pipe thermal expansion. Analysis indicates that this produces a non-linear, directionally sensitive clamp spring rate. Since these spring rates influence the seismic response of a supported piping system, it was deemed necessary to evaluate them further by test. This has been accomplished for the FFTF clamps. A more standard insulated pipe clamp, which does not incorporate Belleville springs to accommodate thermal expansion, was also tested. This type clamp is simple in design, and economically attractive. It may have wide application prospects for use in LMFBR small bore auxiliary piping operating at temperatures below 427 0 C. Load deflection tests were conducted on 2.54 CM and 7.62 CM diameter samples of these commercial clamps

Structural integrity of whipping pipes following a postulated circumferential break - a contribution to determining strain levels acceptable under faulted conditions

International Nuclear Information System (INIS)

Charalambus, B.; Labes, M.

1993-01-01

It is postulated that a break of a thin-walled pipe does not cause a subsequent break in the pipe in the vicinity of a plastic hinge even when the wall is weakened by a 60 circumferential crack of a depth of 30% of the wall thickness on the tension side. This pipe behavior is the result of plastic buckling in the compression side and applies to pipes of diameter-to-thickness ratio larger than 20. For this type of pipe, the axial strains decrease with increasing diameter-to-thickness ratio in the tension side. As the pipe is only loaded in one direction, there is no cyclic behavior that can trigger a subsequent break. (orig.)

Rationally designed graphene-nanotube 3D architectures with a seamless nodal junction for efficient energy conversion and storage.

Science.gov (United States)

Xue, Yuhua; Ding, Yong; Niu, Jianbing; Xia, Zhenhai; Roy, Ajit; Chen, Hao; Qu, Jia; Wang, Zhong Lin; Dai, Liming

2015-09-01

One-dimensional (1D) carbon nanotubes (CNTs) and 2D single-atomic layer graphene have superior thermal, electrical, and mechanical properties. However, these nanomaterials exhibit poor out-of-plane properties due to the weak van der Waals interaction in the transverse direction between graphitic layers. Recent theoretical studies indicate that rationally designed 3D architectures could have desirable out-of-plane properties while maintaining in-plane properties by growing CNTs and graphene into 3D architectures with a seamless nodal junction. However, the experimental realization of seamlessly-bonded architectures remains a challenge. We developed a strategy of creating 3D graphene-CNT hollow fibers with radially aligned CNTs (RACNTs) seamlessly sheathed by a cylindrical graphene layer through a one-step chemical vapor deposition using an anodized aluminum wire template. By controlling the aluminum wire diameter and anodization time, the length of the RACNTs and diameter of the graphene hollow fiber can be tuned, enabling efficient energy conversion and storage. These fibers, with a controllable surface area, meso-/micropores, and superior electrical properties, are excellent electrode materials for all-solid-state wire-shaped supercapacitors with poly(vinyl alcohol)/H2SO4 as the electrolyte and binder, exhibiting a surface-specific capacitance of 89.4 mF/cm(2) and length-specific capacitance up to 23.9 mF/cm, - one to four times the corresponding record-high capacities reported for other fiber-like supercapacitors. Dye-sensitized solar cells, fabricated using the fiber as a counter electrode, showed a power conversion efficiency of 6.8% and outperformed their counterparts with an expensive Pt wire counter electrode by a factor of 2.5. These novel fiber-shaped graphene-RACNT energy conversion and storage devices are so flexible they can be woven into fabrics as power sources.

Remote mechanized equipment for the repair and replacement of boiling water reactor recirculation loop piping

International Nuclear Information System (INIS)

Mauser, D.; Busch, D.F.

1983-01-01

Equipment has been assembled for the remote repair or replacement of boiling water reactor nuclear plant piping in the diameter range of 4 to 28 inches (10-71 cm). The objectives of this program were to produce high-quality pipe welds, reduce plant downtime, and reduce man-rem exposure. The repair strategy was to permit repair personnel to install and check out the repair subsystems and then leave the radiation zone allowing the operations to be conducted at a distance of up to 300 feet (91 m) from the operator. The complete repair system comprises subsystems for pipe severing, dimensional gaging, joint preparation, counterboring, welding, postweld nondestructive inspection (conceptual design), and audio, electronic, and visual monitoring of all operations. Components for all subsystems, excluding those for postweld nondestructive inspection, were purchased and modified as needed for integration into the repair system. Subsystems were designed for two sizes of Type 304 stainless steelpipe. For smaller, 12-inch-diameter (30.5 cm) pipe, severing is accomplished by a power hack saw and joint preparation and counterboring by an internally mounted lathe. The 22-inch-diameter (56 cm) pipe is severed, prepared, and counterbored using an externally mounted, single-point machining device. Dimensional gaging is performed to characterize the pipe geometry relative to a fixed external reference surface, allowing the placement of the joint preparation and the counterbore to be optimized. For both pipe sizes, a track-mounted gas tungsten-arc welding head with filler wire feed is used

A simplified leak-before-break evaluation procedure for austenitic and ferritic steel piping

Energy Technology Data Exchange (ETDEWEB)

Gamble, R.M.; Zahoor, A.; Ghassemi, B. [NOVETECH Corp., Rockville, MD (United States)

1994-10-01

A simplified procedure has been defined for computing the allowable circumferential throughwall crack length as a function of applied loads in piping. This procedure has been defined to enable leak-before-break (LBB) evaluations to be performed without complex and time consuming analyses. The development of the LBB evaluation procedure is similar to that now used in Section 11 of the ASME Code for evaluation of part-throughwall flaws found in piping. The LBB evaluation procedure was bench marked using experimental data obtained from pipes having circumferential throughwall flaws. Comparisons of the experimental and predicted load carrying capacities indicate that the method has a conservative bias, such that for at least 97% of the experiments the experimental load is equal to or greater than 90% of the predicted load. The procedures described in this report are applicable to pipe and pipe fittings with: (1) wrought austenitic steel (Ni-Cr-Fe alloy) having a specified minimum yield strength less than 45 ksi, and gas metal-arc, submerged arc and shielded metal-arc austenitic welds, and (2) seamless or welded wrought carbon steel having a minimum yield strength not greater than 40 ksi, and associated weld materials. The procedures can be used for cast austenitic steel when adequate information is available to place the cast material toughness into one of the categories identified later in this report for austenitic wrought and weld materials.

Casing of preinsulated district heating pipes. Functional Requirements. Scientific report

Energy Technology Data Exchange (ETDEWEB)

Bryder, K.L.; Feld, T.; Randloev, P.; Vestergaard, J.B.; Noergaard Pedersen, H.; Palle, S.; Amby, L.

1996-10-01

Requirements for the wall thickness of the casing pipes in Europe were formulated to clarify the laying conditions, representative for the European district heating areas. We achieved a broad estimate by defining four scenarios for the laying of district heating pipes. It is common to the four scenarios that that all bends, branches etc. are always laid in sand. The four scenarios are differentiated by soil types. The soil types include: Uniform sand, Well graded gravel, Sand with fines and Sand with crushed stone. In the following analysis it was possible to examine the influence from following parameters: Casing thickness; Diameter of steel pipe; Diameter of casing; Material properties (PUR and PE); Soil type. The results from the model showed that uniform sand is the absolute best soil type. Based on the results from and earlier project a laboratory method has been developed. The result was a test method based on the indentation of three mandrels with a diameter of {phi}30 mm with a taper with an angle of 45 deg. and with roundings on the apex of R5 mm, R10 mm and R15 mm, respectively. The mandrels simulate stones. The examinations among other things showed that even a 1.5 mm casing demands an indentation of 20 mm with a R5 mm mandrel before it is perforated. The demanded force is 1.6 kN, which is considerably higher than the theoretically highest force in an actual situation. On this background it is recommended that the minimum requirement for the wall thickness of the casings with diameters less than 200 mm should still follow the EN 253, whereas the minimum requirement for the larger casing pipes securely can be reduced. Based on the tests and an evaluation of the safety factors it is proposed that the wall thickness for the largest pipes can be reduced 50%. Thus the wall thickness of an 800 mm casing should be 6.6 mm with a linear reduction down to 3 mm for 180 mm casing. (EG)

Supporting Seamless Learning Experiences

NARCIS (Netherlands)

Rusman, Ellen; Specht, Marcus; Klemke, Roland; Ternier, Stefaan; Tan, Esther; Firssova, Olga; Stracke, Christian M.; Suarez, Angel; Van Dijk, Guido

2017-01-01

Elevator pitch about Seamless learning for the Board of the Open University of the Netherlands. People increasingly learn in different (physical and social) settings with less effort than 50 years ago, as both technological as well as physical infrastructures allow them to do so. Learners easily

International piping integrity research group (IPIRG) program final report

International Nuclear Information System (INIS)

Schmidt, R.; Wilkowski, G.; Scott, P.; Olsen, R.; Marschall, C.; Vieth, P.; Paul, D.

1992-04-01

This is the final report of the International Piping Integrity Research Group (IPIRG) Programme. The IPIRG Programme was an international group programme managed by the U.S. Nuclear Regulatory Commission and funded by a consortium of organizations from nine nations: Canada, France, Italy, Japan, Sweden, Switzerland, Taiwan, the United Kingdom, and the United states. The objective of the programme was to develop data needed to verify engineering methods for assessing the integrity of nuclear power plant piping that contains circumferential defects. The primary focus was an experimental task that investigated the behaviour of circumferentially flawed piping and piping systems to high-rate loading typical of seismic events. To accomplish these objectives a unique pipe loop test facility was designed and constructed. The pipe system was an expansion loop with over 30 m of 406-mm diameter pipe and five long radius elbows. Five experiments on flawed piping were conducted to failure in this facility with dynamic excitation. The report: provides background information on leak-before-break and flaw evaluation procedures in piping; summarizes the technical results of the programme; gives a relatively detailed assessment of the results from the various pipe fracture experiments and complementary analyses; and, summarizes the advances in the state-of-the-art of pipe fracture technology resulting from the IPIRG Program

Flow induced vibrations of piping

International Nuclear Information System (INIS)

Gibert, R.J.; Axisa, F.

1977-01-01

In order to design the supports of piping systems, estimations of the vibrations induced by the fluid conveyed through the pipes are generally needed. For that purpose it is necessary to calculate the model parameters of liquid containing pipes. In most computer codes, fluid effects are accounted for just by adding the fluid mass to the structure. This may lead to serious errors. This paper presents a method to take into account these effects, by solving a coupled mechanical-acoustical problem: the computer code TEDEL of the C.E.A /D.E.M.T. System, based on the finite-elements method, has been extended to calculate simultaneously the pressure fluctuations in the fluid and the vibrations of the pipe. By this way the mechanical-acoustical coupled eigenmodes of any piping system can be obtained. These eigenmodes are used to determine the response of the system to various sources. Equations have been written in the hypohesis that acoustical wave lengths remain large compared to the diameter of the pipe. The method has been checked by an experiment performed on the GASCOGNE loop at D.E.M.T. The piping system under test consists of a tube with four elbows. The circuit is ended at each extremity by a large vessel which performs acoustical isolation by generating modes for the pressure. Excitation of the circuit is caused by a valve located near the downstream vessel. This provides an efficient localised broad band acoustical source. The comparison between the test results and the calculations has shown that the low frequency resonant characteristics of the pipe and the vibrational amplitude at various flow-rates can be correctly predicted

Optimization of a pump-pipe system by dynamic programming

DEFF Research Database (Denmark)

Vidal, Rene Victor Valqui; Ferreira, Jose S.

1984-01-01

In this paper the problem of minimizing the total cost of a pump-pipe system in series is considered. The route of the pipeline and the number of pumping stations are known. The optimization will then consist in determining the control variables, diameter and thickness of the pipe and the size of...... of the pumps. A general mathematical model is formulated and Dynamic Programming is used to find an optimal solution....

Inspection Method for Contact Condition of Soil on the Surface of Underground Pipe Utilizing Resonance of Transverse Lamb Wave

Science.gov (United States)

Tanigawa, Hiroshi; Seno, Hiroaki; Watanabe, Yoshiaki; Nakajima, Koshiro

1998-05-01

A nondestructive inspection method to estimate the contact condition of soil on the surface of an underground pipe, utilizing the resonance of a transverse Lamb wave circulating along the pipe wall is proposed.The Q factor of the resonance is considered and measured under some contact conditions by sweeping the vibrating frequency in a 150-mm-inner diameter Fiberglass Reinforced Plastic Mortar (FRPM) pipe. It is confirmed that the Q factor shows a clear response to the change in the contact conditions. For example, the Q factor is 8.4 when the pipe is in ideal contact with the soil plane and goes up to 19.2 when a 100-mm-diameter void is located at the contact surface of the soil.The spatial resolution of the proposed inspection method is also measured by moving the sensing point along the direction of laying the length of the pipe into a 85-mm-diameter void. The resolution of the proposed method is estimated at about 50 mm.

The Natural Convection Heat Transfer inside Vertical Pipe: Characteristic of Pipe Flow according to the Boundary layer

Energy Technology Data Exchange (ETDEWEB)

Ohk, Seung Min; Chung, Bum Jin [Kyunghee University, Yongin (Korea, Republic of)

2016-05-15

The Passive Cooling System (PCS) driven by natural forces drew research attention since Fukushima nuclear power plant accident. This study investigated the natural convection heat transfer inside of vertical pipe with emphasis on the phenomena regarding the boundary layer interaction. Numerical calculations were carried out using FLUENT 6.3. Experiments were performed for the parts of the cases to explore the accuracy of calculation. Based on the analogy, heat transfer experiment is replaced by mass transfer experiment using sulfuric acid copper sulfate (CuSO{sub 4}. H{sub 2}SO{sub 4}) electroplating system. The natural convection heat transfer inside a vertical pipe is studied experimentally and numerically. Experiments were carried out using sulfuric acid-copper sulfate (H{sub 2}SO{sub 4}-CuSO{sub 4}) based on the analogy concept between heat and mass transfer system. Numerical analysis was carried out using FLUENT 6.3. It is concluded that the boundary layer interaction along the flow passage influences the heat transfer, which is affected by the length, diameter, and Prandtl number. For the large diameter and high Prandtl number cases, where the thermal boundary layers do not interfered along the pipe, the heat transfer agreed with vertical flat plate for laminar and turbulent natural convection correlation within 8%. When the flow becomes steady state, the forced convective flow appears in the bottom of the vertical pipe and natural convection flow appears near the exit. It is different behavior from the flow on the parallel vertical flat plates. Nevertheless, the heat transfer was not different greatly compared with those of vertical plate.

Assessment of short through-wall circumferential cracks in pipes. Experiments and analysis: March 1990--December 1994

Energy Technology Data Exchange (ETDEWEB)

Brust, F.W.; Scott, P.; Rahman, S. [Battelle, Columbus, OH (United States)] [and others

1995-04-01

This topical report summarizes the work performed for the Nuclear Regulatory Commission`s (NRC) research program entitled ``Short Cracks in Piping and Piping Welds`` that specifically focuses on pipes with short through-wall cracks. Previous NRC efforts, conducted under the Degraded Piping Program, focused on understanding the fracture behavior of larger cracks in piping and fundamental fracture mechanics developments necessary for this technology. This report gives details on: (1) material property determinations, (2) pipe fracture experiments, and (3) development, modification, and validation of fracture analysis methods. The material property data required to analyze the experimental results are included. These data were also implemented into the NRC`s PIFRAC database. Three pipe experiments with short through-wall cracks were conducted on large diameter pipe. Also, experiments were conducted on a large-diameter uncracked pipe and a pipe with a moderate-size through-wall crack. The analysis results reported here focus on simple predictive methods based on the J-Tearing theory as well as limit-load and ASME Section 11 analyses. Some of these methods were improved for short-crack-length predictions. The accuracy of the various methods was determined by comparisons with experimental results from this and other programs. 69 refs., 124 figs, 49 tabs.

Assessment of short through-wall circumferential cracks in pipes. Experiments and analysis: March 1990--December 1994

International Nuclear Information System (INIS)

Brust, F.W.; Scott, P.; Rahman, S.

1995-04-01

This topical report summarizes the work performed for the Nuclear Regulatory Commission's (NRC) research program entitled ''Short Cracks in Piping and Piping Welds'' that specifically focuses on pipes with short through-wall cracks. Previous NRC efforts, conducted under the Degraded Piping Program, focused on understanding the fracture behavior of larger cracks in piping and fundamental fracture mechanics developments necessary for this technology. This report gives details on: (1) material property determinations, (2) pipe fracture experiments, and (3) development, modification, and validation of fracture analysis methods. The material property data required to analyze the experimental results are included. These data were also implemented into the NRC's PIFRAC database. Three pipe experiments with short through-wall cracks were conducted on large diameter pipe. Also, experiments were conducted on a large-diameter uncracked pipe and a pipe with a moderate-size through-wall crack. The analysis results reported here focus on simple predictive methods based on the J-Tearing theory as well as limit-load and ASME Section 11 analyses. Some of these methods were improved for short-crack-length predictions. The accuracy of the various methods was determined by comparisons with experimental results from this and other programs. 69 refs., 124 figs, 49 tabs

Wall Thickness Measurement Of Insulated Pipe By Tangential Radiography Technique Using Ir 192

International Nuclear Information System (INIS)

Soedarjo

2000-01-01

Insulation pipe wall thickness by tangential radiography technique has been carried out using 41 Curie Iridium 192 source has activity for two carbon steel pipes. The outer diameter of the first pipe is 90 mm, wall thickness is 75.0 mm, source film film distance is 609.5 mm, source tangential point of insulation is 489.5 mm and exposure time 3 minute and 25 second. From the calculation, the first pipe thickness is found to be 12.54 mm and for the second pipe is 8.42 mm. The thickness is due to inaccuracy in reading the pipe thickness on radiography film and the geometry distortion radiation path

Optimal Pipe Size Design for Looped Irrigation Water Supply System Using Harmony Search: Saemangeum Project Area

Science.gov (United States)

Lee, Ho Min; Sadollah, Ali

2015-01-01

Water supply systems are mainly classified into branched and looped network systems. The main difference between these two systems is that, in a branched network system, the flow within each pipe is a known value, whereas in a looped network system, the flow in each pipe is considered an unknown value. Therefore, an analysis of a looped network system is a more complex task. This study aims to develop a technique for estimating the optimal pipe diameter for a looped agricultural irrigation water supply system using a harmony search algorithm, which is an optimization technique. This study mainly serves two purposes. The first is to develop an algorithm and a program for estimating a cost-effective pipe diameter for agricultural irrigation water supply systems using optimization techniques. The second is to validate the developed program by applying the proposed optimized cost-effective pipe diameter to an actual study region (Saemangeum project area, zone 6). The results suggest that the optimal design program, which applies an optimization theory and enhances user convenience, can be effectively applied for the real systems of a looped agricultural irrigation water supply. PMID:25874252

Optimal Pipe Size Design for Looped Irrigation Water Supply System Using Harmony Search: Saemangeum Project Area

Directory of Open Access Journals (Sweden)

Do Guen Yoo

2015-01-01

Full Text Available Water supply systems are mainly classified into branched and looped network systems. The main difference between these two systems is that, in a branched network system, the flow within each pipe is a known value, whereas in a looped network system, the flow in each pipe is considered an unknown value. Therefore, an analysis of a looped network system is a more complex task. This study aims to develop a technique for estimating the optimal pipe diameter for a looped agricultural irrigation water supply system using a harmony search algorithm, which is an optimization technique. This study mainly serves two purposes. The first is to develop an algorithm and a program for estimating a cost-effective pipe diameter for agricultural irrigation water supply systems using optimization techniques. The second is to validate the developed program by applying the proposed optimized cost-effective pipe diameter to an actual study region (Saemangeum project area, zone 6. The results suggest that the optimal design program, which applies an optimization theory and enhances user convenience, can be effectively applied for the real systems of a looped agricultural irrigation water supply.

FFTF report: FFTF piping installation and welding techniques

International Nuclear Information System (INIS)

Gilles, J.

1975-01-01

The main sodium piping with a diameter of 16'' or 28 '' is being installed at the FFTF construction site starting in December 1974. The supplier and authority demarcations are: Combustion Engineering supplies the reactor vessel, guard vessel and adjoining pipes and uses the machine welding equipment ''Dimetrics''; for the piping system of the primary and secondary loops the pipes manufactured by Rollmet at HUICO, Pasco, were delivered and prefabricated there, as far as compatible with the installation. ''Astroarc'' welding machines are used by Bechtel for the piping prefabrication in the weld laboratory as well as on site at the construction site. Technical welding problems occurring during the course of the installation at the construction site and several during this time are described. At present 6 weld seams in the reactor and 14 weld seams in the secondary loop are accepted. The requirement exists to carry out as many welds as possible automatically, in order to produce sodium pipe welds of high technical quality and which are reproducible. The welding equipment is described

Casing of preinsulated district heating pipes. Functional Requirements. Enclosures

Energy Technology Data Exchange (ETDEWEB)

Bryder, K.L.; Feld, T.; Randloev, P.; Vestergaard, J.B.; Noergaard Pedersen, H.; Palle, S.; Amby, L.

1996-10-01

Requirements for the wall thickness of the casing pipes in Europe were formulated. In order to clarify the laying conditions, representative for the European district heating areas. It was possible to achieve a sufficiently broad estimate by defining four scenarios for the laying of district heating pipes. It is common to the four scenarios that that all bends, branches etc. are always laid in sand. The four scenarios are differentiated by soil types. The soil types include: Uniform sand, Well graded gravel, Sand with fines and Sand with crushed stone. In the following analysis it was possible to examine the influence from following parameters: Casing thickness; Diameter of steel pipe; Diameter of casing; Material properties (PUR and PE); Soil type. The results from the model showed that uniform sand is the absolute best soil type. Based on the results from and earlier project a laboratory method has been developed. The result was a test method based on the indentation of three mandrels with a diameter of {phi}30 mm with a taper with an angle of 45 deg. and with roundings on the apex of R5 mm, R10 mm and R15 mm, respectively. The mandrels simulate stones. The examinations among other things showed that even a 1.5 mm casing demands an indentation of 20 mm with a R5 mm mandrel before it is perforated. The demanded force is 1.6 kN, which is considerably higher than the theoretically highest force in an actual situation. On this background it is recommended that the minimum requirement for the wall thickness of the casings with diameters less than 200 mm should still follow the EN 253, whereas the minimum requirement for the larger casing pipes securely can be reduced. Based on the tests and an evaluation of the safety factors it is proposed that the wall thickness for the largest pipes can be reduced 50%. Thus the wall thickness of an 800 mm casing should be 6.6 mm with a linear reduction down to 3 mm for 180 mm casing. (EG)

Seamless learning: Technology-enhanced learning from practical experiences across contexts

NARCIS (Netherlands)

Rusman, Ellen

2018-01-01

Rusman, E. (2018, 8th of June). Seamless learning: Technology-enhanced learning from practical experiences across contexts. Keynote presentation at the Seamless learning conference, Maastricht, The Netherlands. http://www.ou.nl/slc

Seamless-merging-oriented parallel inverse lithography technology

International Nuclear Information System (INIS)

Yang Yiwei; Shi Zheng; Shen Shanhu

2009-01-01

Inverse lithography technology (ILT), a promising resolution enhancement technology (RET) used in next generations of IC manufacture, has the capability to push lithography to its limit. However, the existing methods of ILT are either time-consuming due to the large layout in a single process, or not accurate enough due to simply block merging in the parallel process. The seamless-merging-oriented parallel ILT method proposed in this paper is fast because of the parallel process; and most importantly, convergence enhancement penalty terms (CEPT) introduced in the parallel ILT optimization process take the environment into consideration as well as environmental change through target updating. This method increases the similarity of the overlapped area between guard-bands and work units, makes the merging process approach seamless and hence reduces hot-spots. The experimental results show that seamless-merging-oriented parallel ILT not only accelerates the optimization process, but also significantly improves the quality of ILT.

Piping failures in United States nuclear power plants 1961-1995

International Nuclear Information System (INIS)

Bush, S.H.; Do, M.J.; Slavich, A.L.; Chockie, A.D.

1996-01-01

Over 1500 reported piping failures were identified and summarized based on an extensive review of tens of thousands of event reports that have been submitted to the US regulatory agencies over the last 35 years. The data base contains only piping failures; failures in vessels, pumps, valves and steam generators or any cracks that were not through-wall are not included. It was observed that there has been a marked decrease in the number of failures after 1983 for almost all sizes of pipes. This is likely due to the changes in the reporting requirements at that time and the corrective actions taken by utilities to minimize fatigue failures of small lines and IGSCC in BWRs. One failure mechanism that continues to occur is erosion-corrosion, which accounts for most of the ruptures reported and probably is responsible for the absence of downward trends in ruptures. Fatigue-vibration is also a significant contributor to piping failures. However, most of such events occur in lines approx. one inch or less in diameter. Together, erosion-corrosion and fatigue-vibration account for over 43 per cent of the failures. The overwhelming majority of failures have been leaks, over half the failures occurred in pipes with a diameter of one inch or less. Included in the report is a listing of the number of welds in various systems in LWRs

The integral analysis of 40 mm diameter pipe rupture in cooling system of fusion facility W7-X with ASTEC code

Energy Technology Data Exchange (ETDEWEB)

Kačegavičius, Tomas, E-mail: Tomas.Kacegavicius@lei.lt; Povilaitis, Mantas, E-mail: Mantas.Povilaitis@lei.lt

2015-12-15

Highlights: • The analysis of loss-of-coolant accident (LOCA) in W7-X facility. • Burst disc is sufficient to prevent pressure inside the plasma vessel exceeding 110 kPa. • Developed model of the cooling system adequately represents the expected phenomena. - Abstract: Fusion is the energy production technology, which could potentially solve problems with growing energy demand of population in the future. Wendelstein 7-X (W7-X) is an experimental facility of stellarator type, which is currently being built at the Max-Planck-Institute for Plasmaphysics located in Greifswald, Germany. W7-X shall demonstrate that in future the energy could be produced in such type of fusion reactors. The safety analysis is required before the operation of the facility could be started. A rupture of 40 mm diameter pipe, which is connected to the divertor unit (module for plasma cooling) to ensure heat removal from the vacuum vessel in case of no-plasma operation mode “baking” is one of the design basis accidents to be investigated. During “baking” mode the vacuum vessel structures and working fluid – water are heated to the temperature 160 °C. This accident was selected for the detailed analysis using integral code ASTEC, which is developed by IRSN (France) and GRS mbH (Germany). This paper presents the integral analysis of W7-X response to a selected accident scenario. The model of the main cooling circuit and “baking” circuit was developed for ASTEC code. There were analysed two cases: (1) rupture of a pipe connected to the upper divertor unit and (2) rupture of a pipe connected to the lower divertor unit. The results of analysis showed that in both cases the water is almost completely released from the units into the plasma vessel. In both cases the pressure in the plasma vessel rapidly increases and in 28 s the set point for burst disc opening is reached preventing further pressurisation.

Multi-dimensional two-phase flow measurements in a large-diameter pipe using wire-mesh sensor

International Nuclear Information System (INIS)

Kanai, Taizo; Furuya, Masahiro; Arai, Takahiro; Shirakawa, Kenetsu; Nishi, Yoshihisa; Ueda, Nobuyuki

2011-01-01

The authors developed a method of measurement to determine the multi-dimensionality of two phase flow. A wire-mesh sensor (WMS) can acquire a void fraction distribution at a high temporal and spatial resolution and also estimate the velocity of a vertical rising flow by investigating the signal time-delay of the upstream WMS relative to downstream. Previously, one-dimensional velocity was estimated by using the same point of each WMS at a temporal resolution of 1.0 - 5.0 s. The authors propose to extend this time series analysis to estimate the multi-dimensional velocity profile via cross-correlation analysis between a point of upstream WMS and multiple points downstream. Bubbles behave in various ways according to size, which is used to classify them into certain groups via wavelet analysis before cross-correlation analysis. This method was verified by air-water straight and swirl flows within a large-diameter vertical pipe. A high-speed camera is used to set the parameter of cross-correlation analysis. The results revealed that for the rising straight and swirl flows, large scale bubbles tend to move to the center, while the small bubble is pushed to the outside or sucked into the space where the large bubbles existed. Moreover, it is found that this method can estimate the rotational component of velocity of the swirl flow as well as measuring the multi-dimensional velocity vector at high temporal resolutions of 0.2 s. (author)

Water driven turbine/brush pipe cleaner

Science.gov (United States)

Werlink, Rudy J. (Inventor)

1995-01-01

Assemblies are disclosed for cleaning the inside walls of pipes and tubes. A first embodiment includes a small turbine with angled blades axially mounted on one end of a standoff support. An O-ring for stabilizing the assembly within the pipe is mounted in a groove within the outer ring. A replaceable circular brush is fixedly mounted on the opposite end of the standoff support and can be used for cleaning tubes and pipes of various diameters, lengths and configurations. The turbine, standoff support, and brush spin in unison relative to a hub bearing that is fixedly attached to a wire upstream of the assembly. The nonrotating wire is for retaining the assembly in tension and enabling return of the assembly to the pipe entrance. The assembly is initially placed in the pipe or tube to be cleaned. A pressurized water or solution source is provided at a required flow-rate to propel the assembly through the pipe or tube. The upstream water pressure propels and spins the turbine, standoff support and brush. The rotating brush combined with the solution cleans the inside of the pipe. The solution flows out of the other end of the pipe with the brush rotation controlled by the flow-rate. A second embodiment is similar to the first embodiment but instead includes a circular shaped brush with ring backing mounted in the groove of the exterior ring of the turbine, and also reduces the size of the standoff support or eliminates the standoff support.

Structural integrity assessment of piping components

International Nuclear Information System (INIS)

Kushwaha, H.S.; Chattopadhyay, J.

2008-01-01

Integrity assessment of piping components is very essential for safe and reliable operation of power plants. Over the last several decades, considerable work has been done throughout the world to develop a methodology for integrity assessment of pipes and elbows, appropriate for the material involved. However, there is scope of further development/improvement of issues, particularly for pipe bends, that are important for accurate integrity assessment of piping. Considering this aspect, a comprehensive Component Integrity Test Program was initiated in 1998 at Bhabha Atomic Research Centre (BARC), India. In this program, both theoretical and experimental investigations were undertaken to address various issues related to the integrity assessment of pipes and elbows. Under the experimental investigations, fracture mechanics tests have been conducted on pipes and elbows of 200-400 mm nominal bore (NB) diameter with various crack configurations and sizes under different loading conditions. Tests on small tensile and three point bend specimens, machined from the tested pipes, have also been done to evaluate the actual stress-strain and fracture resistance properties of pipe/elbow material. The load-deflection curve and crack initiation loads predicted by non-linear finite element analysis matched well with the experimental results. The theoretical collapse moments of throughwall circumferentially cracked elbows, predicted by the recently developed equations, are found to be closer to the test data compared to the other existing equations. The role of stress triaxialities ahead of crack tip is also shown in the transferability of J-Resistance curve from specimen to component. The cyclic loading and system compliance effect on the load carrying capacity of piping components are investigated and new recommendations are made. (author)

Experiment on electrolysis decontamination of stainless steel pipes

International Nuclear Information System (INIS)

Wang Dongwen; Dou Tianjun; Zhao Yujie

2004-01-01

A new electrolytic decontamination method used metal balls as conducting anode was investigated. The influences of current density, solution property and diameter of pipes on efficiency of electrolytic decontamination were examined and the efficiency of this method was compared with that of common electrolytic method under the same experimental conditions. Decontamination of samples of stainless steel pipes contaminated by plutonium was performed. Experimental results indicate that decontamination of stainless steel pipes contaminated by plutonium can be achieved at the optimum conditions of greater than 0.2 A·cm -2 current density, 5% sulfuric acid electrolyte and 5 min electrolysis. This method can be used in the decontamination of a wide variety of decommissioned metal materials. (author)

78 FR 73828 - Certain Oil Country Tubular Goods From the People's Republic of China: Rescission of Antidumping...

Science.gov (United States)

2013-12-09

... Seamless Steel Pipe Co., Ltd. 41. Changshu Chengfeng Machinery Manufacturing Co., Ltd. 42. Changshu Lijia... Longcheng Steel Pipe Manufacturing Co., Ltd. 61. Chengdu Heyi Steel Tube Industrial Co., Ltd. 62. Chengdu... Manufacturing Co., Ltd 134. Hebei Huike Steel Pipe Co., Ltd. 135. Hebei Litonglian Seamless Steel Pipe 136...

Stability of cracked pipe under inertial stresses. Subtask 1.1 final report

International Nuclear Information System (INIS)

Scott, P.; Wilson, M.; Olson, R.; Marschall, C.; Schmidt, R.; Wilkowski, G.

1994-08-01

This report presents the results of the pipe fracture experiments, analyses, and material characterization efforts performed within Subtask 1.1 of the IPIRG Program. The objective of Subtask 1.1 was to experimentally verify the analysis methodologies for circumferentially cracked pipe subjected primarily to inertial stresses. Eight cracked-pipe experiments were conducted on 6-inch nominal diameter TP304 and A106B pipe. The experimental procedure was developed using nonlinear time-history finite element analyses which included the nonlinear behavior due to the crack. The model did an excellent job of predicting the displacements, forces, and times to maximum moment. The comparison of the experimental loads to the predicted loads by the Net-Section-Collapse (NSC), Dimensionless Plastic-Zone Parameter, J-estimation schemes, R6, and ASME Section XI in-service flaw assessment criteria tended to underpredict the measured bending moments except for the NSC analysis of the A106B pipe. The effects of flaw geometry and loading history on toughness were evaluated by calculating the toughness from the pipe tests and comparing these results to C(l) values. These effects were found to be variable. The surface-crack geometry tended to increase the toughness (relative to CM results), whereas a negative load-ratio significantly decreased the TP304 stainless steel surface-cracked pipe apparent toughness. The inertial experiments tended to achieve complete failure within a few cycles after reaching maximum load in these relatively small diameter pipe experiments. Hence, a load-controlled fracture mechanics analysis may be more appropriate than a displacement-controlled analysis for these tests

Long liquid slugs in stratified gas/liquid flow in horizontal and slightly inclined pipes

NARCIS (Netherlands)

Kadri, U.

2009-01-01

Long liquid slugs reaching several hundreds pipe diameter may appear when transporting gas and liquid in horizontal and near horizontal pipes. The long slugs cause system vibration and separation difficulties that may lead to operational failures. Identifying and predicting the time and length

Self-contained pipe cutting shear. Innovative technology summary report

International Nuclear Information System (INIS)

1998-11-01

The US Department of Energy (DO) is in the process of decontaminating and decommissioning (D and D) many of its nuclear facilities throughout the country. Facilities have to be dismantled and demolition waste must be sized into manageable pieces for handling and disposal. Typically, the facilities undergoing D and D are contaminated, either chemically, radiologically, or both. In its D and D work, the DOE was in need of a tool capable of cutting steel and stainless steel pipe up to 6.4 cm in diameter. The self-contained pipe cutting shear was developed by Lukas Hydraulic GmbH and Co. KG to cut pipes up to 6.4 cm (2.5 in.) in diameter. This tool is a portable, hand-held hydraulic shear that is powered by a built-in rechargeable battery or a portable auxiliary rechargeable battery. Adding to its portability, it contains no hydraulic fluid lines or electrical cords, making it useful in congested areas or in areas with no power. Both curved and straight blades can be attached, making it adaptable to a variety of conditions. This tool is easy to set up, operates quietly, and cuts through pipes quickly. It is especially useful on contaminated pipes, as it crimps the ends while cutting and produces no residual cuttings. This shear is a valuable alternative to baseline technologies such as portable band saws, electric hacksaws, and other hydraulic shears. Costs using the innovative shear for cutting 2.5 cm (1-in.) pipe, for example, are comparable to costs using a conventional shear, approximately 80% of portable bandsaw costs and half of electric hacksaw costs

Standard practice for ultrasonic testing of the Weld Zone of welded pipe and tubing

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice describes general ultrasonic testing procedures for the detection of discontinuities in the weld and adjacent heat affected zones of welded pipe and tubing by scanning with relative motion between the search unit and pipe or tube. When contact or unfocused immersion search units are employed, this practice is intended for tubular products having specified outside diameters ≥2 in. (≥50 mm) and specified wall thicknesses of 1/8to 11/16 in. (3 to 27 mm). When properly focused immersion search units are employed, this practice may also be applied to material of smaller diameter and thinner wall. Note 1—When contact or unfocused immersion search units are used, precautions should be exercised when examining pipes or tubes near the lower specified limits. Certain combinations of search unit size, frequency, thin–wall thicknesses, and small diameters could cause generation of unwanted sound waves that may produce erroneous examination results. 1.2 All surfaces of material to be examined in ...

Leak-before-break behaviour of nuclear piping systems

International Nuclear Information System (INIS)

Bartholome, G.; Wellein, R.

1992-01-01

The general concept for break preclusion of nuclear piping systems in the FRG consists of two main prerequisites: Basic safety; independent redundancies. The leak-before-break behaviour is open of these redundancies and will be verified by fracture mechanics. The following items have to be evaluated: The growth of detected and postulated defects must be negligible in one life time of the plant; the growth behaviour beyond design (i.e. multiple load collectives are taken into account) leads to a stable leak; This leakage of the piping must be detected by an adequate leak detection system long before the critical defect size is reached. The fracture mechanics calculations concerning growth and instability of the relevant defects and corresponding leakage areas are described in more detail. The leak-before-break behaviour is shown for two examples of nuclear piping systems in pressurized water reactors: main coolant line of SIEMENS-PWR 1300 MW (ferritic material, diameter 800 mm); surge line of Russian WWER 440 (austenitic material, diameter 250 mm). The main results are given taking into account the relevant leak detection possibilities. (author). 9 refs, 9 figs

Characteristics on the heat storage and recovery by the underground spiral heat exchange pipe; Chichu maisetsu spiral kan ni yoru chikunetsu shunetsu tokusei

Energy Technology Data Exchange (ETDEWEB)

Imai, I [Kure National College of Technology, Hiroshima (Japan); Taga, M [Kinki University, Osaka (Japan)

1996-10-27

The consistency between the experimental value of a soil temperature and the calculation value of a soil temperature given by a non-steady heat conduction equation was confirmed. The experimental value is obtained by laying a spiral heat exchange pipe in the heat-insulated soil box and circulating hot water forcibly in the pipe. The temperature conductivity in soil significantly influences the heat transfer in soil. The storage performance is improved when the temperature conductivity increases because of the contained moisture. As the difference between the initial soil temperature and circulating water temperature becomes greater, the heat storage and recovery values increase. A thermal core heat transfer is done in the spiral pipe. Therefore, the diameter of the pipe little influences the heat storage performance, and the pitch influences largely. About 50 hours after heat is stored, the storage performance is almost the same as for a straight pipe that uses the spiral diameter as a pipe diameter. To obtain the same heat storage value, the spiral pipe is made of fewer materials than the straight pipe and low in price. The spiral pipe is more advantageous than the straight pipe in the necessary motive power and supply heat of a pump. 1 ref., 11 figs., 1 tab.

Metallurgical factors that contribute to cracking in BWR piping

International Nuclear Information System (INIS)

Weeks, J.R.

1975-01-01

During the fall of 1974 and early winter of 1975, cracks have been discovered in the 4 in. bypass lines of several Boiling Water Reactors (BWR's) in the United States. Further, similar cracks were discovered at two BWR's in Japan during the same period. More recently, cracks have been discovered in the core spray piping and in a furnace-sensitized ''safe end'' and adjacent ''dutchman'' at the Dresden Nuclear Power Station, Unit No. 2. Although inspections at all other U.S. BWR's have not disclosed further instances of cracking in core spray piping, leaking cracks have been found in the core spray piping of two BWR's overseas. Metallurgical examinations of these cracks are not yet complete. The following observations have been made to date. All cracks (except those in the furnace-sensitized safe end and dutchman) occurred in seamless type 304 stainless steel piping or in elbows fabricated from such piping, in the outer heat affected zone of either field or shop welds, in lines isolated from the main primary coolant flow during full power operation, except for the not yet examined cracks in the Monticello bypass lines. The cracks are exclusively intergranular, and occur in metal that has been lightly sensitized by the welding process, with only intermittent grain boundary carbides. They developed in the areas of peak axial residual stresses from welding rather than in the most heavily sensitized areas. No fatigue striations have been found on the fracture surfaces. The evidence received to date strongly indicates that these cracks were caused by intergranular stress corrosion of weld-sensitized stainless steel by BWR water containing greater than 0.2 ppM oxygen. The possible role of fatigue or alternating stresses in this corrosion is not clear. Further, not all the cracks detected to date necessarily have occurred by the same mechanism

A Study on the Influence of Fuel Pipe on Fuel Injection Characteristics of Each Nozzle Hole in Diesel Injector

Directory of Open Access Journals (Sweden)

Luo Fuqiang

2016-01-01

Full Text Available The inner diameter of high pressure fuel pipe has a significant effect on the fuel injection process and the performance of a diesel engine. The spray impact force of each nozzle hole of a conventional injection system of pump-line-nozzle for diesel engine (based on the spray momentum flux and the injection pressure (on a fuel injection pump test rig were measured. With varying fuel injection quantities and pump speed, the effects of the inner diameter of the high pressure fuel pipe on fuel injection process and the fuel injection characteristics of each nozzle hole were analyzed. It was noted from experimental results that the fuel injection pressure changes with variations in the inner diameter of the high pressure fuel pipe and also the injection duration gradually increases with increase in the inner diameter. At low injection pump speed, even with the same geometric fuel deliver rate, the injection duration also increases gradually. Due to throttling effect and reduction in injection pressure, the fuel injection quantities of the injection nozzle were relatively minimal when the inner diameters of the high pressure fuel pipe were respectively small and large. The optimum injection pipe inner diameter for the right quantity for fuel injection falls between the two cases (between small and large. In addition, the injection rate of each nozzle hole increases with the decrease in angle between the needle axis and each of the nozzle hole axis. The fuel injection quantity of each nozzle hole increases while their relative difference decreases with increasing pump speed.

Study on mixing behavior in a tee piping and numerical analyses for evaluation of thermal striping

International Nuclear Information System (INIS)

Kamide, H.; Igarashi, M.; Kawashima, S.; Kimura, N.; Hayashi, K.

2009-01-01

Water experiments were carried out for thermal hydraulic aspects of thermal striping in a mixing tee, which has main to branch diameter ratio of 3. Detailed temperature and velocity fields were measured by a movable thermocouple tree and particle image velocimetry. Flow patterns in the tee were classified into three groups; wall jet, deflecting jet, and impinging jet, which had their own temperature fluctuation profiles, depending on a momentum ratio between the main and branch pipes. Non-dimensional power spectrum density (PSD) of temperature fluctuation showed a unique profile, when the momentum ratio was identical. Numerical simulation based on finite difference method showed alternative vortex development, like Karman vortex series, behind the jet from the branch pipe in the wall jet case. The prominent frequency of the temperature fluctuation in the calculation was 0.2 of St number based on the branch pipe diameter and in good agreement with the experimental results. Mixing behavior in the tee was characterized by the relatively large vortex structures defined by the diameters and the velocities in the pipes

International Piping Integrity Research Group (IPIRG) Program. Final report

International Nuclear Information System (INIS)

Wilkowski, G.; Schmidt, R.; Scott, P.

1997-06-01

This is the final report of the International Piping Integrity Research Group (IPIRG) Program. The IPIRG Program was an international group program managed by the U.S. Nuclear Regulatory Commission and funded by a consortium of organizations from nine nations: Canada, France, Italy, Japan, Sweden, Switzerland, Taiwan, the United Kingdom, and the United States. The program objective was to develop data needed to verify engineering methods for assessing the integrity of circumferentially-cracked nuclear power plant piping. The primary focus was an experimental task that investigated the behavior of circumferentially flawed piping systems subjected to high-rate loadings typical of seismic events. To accomplish these objectives a pipe system fabricated as an expansion loop with over 30 meters of 16-inch diameter pipe and five long radius elbows was constructed. Five dynamic, cyclic, flawed piping experiments were conducted using this facility. This report: (1) provides background information on leak-before-break and flaw evaluation procedures for piping, (2) summarizes technical results of the program, (3) gives a relatively detailed assessment of the results from the pipe fracture experiments and complementary analyses, and (4) summarizes advances in the state-of-the-art of pipe fracture technology resulting from the IPIRG program

International Piping Integrity Research Group (IPIRG) Program. Final report

Energy Technology Data Exchange (ETDEWEB)

Wilkowski, G.; Schmidt, R.; Scott, P. [and others

1997-06-01

This is the final report of the International Piping Integrity Research Group (IPIRG) Program. The IPIRG Program was an international group program managed by the U.S. Nuclear Regulatory Commission and funded by a consortium of organizations from nine nations: Canada, France, Italy, Japan, Sweden, Switzerland, Taiwan, the United Kingdom, and the United States. The program objective was to develop data needed to verify engineering methods for assessing the integrity of circumferentially-cracked nuclear power plant piping. The primary focus was an experimental task that investigated the behavior of circumferentially flawed piping systems subjected to high-rate loadings typical of seismic events. To accomplish these objectives a pipe system fabricated as an expansion loop with over 30 meters of 16-inch diameter pipe and five long radius elbows was constructed. Five dynamic, cyclic, flawed piping experiments were conducted using this facility. This report: (1) provides background information on leak-before-break and flaw evaluation procedures for piping, (2) summarizes technical results of the program, (3) gives a relatively detailed assessment of the results from the pipe fracture experiments and complementary analyses, and (4) summarizes advances in the state-of-the-art of pipe fracture technology resulting from the IPIRG program.

An investigation of wall temperature characteristics to evaluate thermal fatigue at a T-junction pipe

International Nuclear Information System (INIS)

Miyoshi, Koji; Nakamura, Akira; Utanohara, Yoichi; Takenaka, Nobuyuki

2014-01-01

Thermal fatigue cracking may initiate at a T-junction pipe where high and low temperature fluids mix. In this study, wall temperature characteristics at a T-junction pipe were investigated to improve the evaluation method for thermal fatigue. The stainless steel test section consisted of a horizontal main pipe (diameter, 150 mm) and a T-junction connected to a vertical branch pipe (diameter, 50 mm). The inlet flow velocities in the main and branch pipes were set to 0.99 m/s and 0.66 m/s respectively to produce a wall jet pattern in which the jet from the branch pipe was bent by the main pipe flow and made to flow along the pipe wall. The temperature difference was 34.1 K. A total of 148 thermocouples were installed to measure the wall temperature on the pipe inner surface in the downstream region. The maximum of temperature fluctuation intensity on the pipe inner surface was measured as 5% of the fluid temperature difference at the inlets. The dominant frequency of the large temperature fluctuations in the region downstream from z = 0.5D m was equal to 0.2 of the Strouhal number, which was equal to the frequency caused by the vortex streets generated around the jet flow. The large temperature fluctuation was also observed with the period of about 10 s. The fluctuation was caused by spreading of the heated region in the circumferential direction. (author)

Technology of application of pipe's arc of the integral pipeline in power plant 'Oslomej'

Directory of Open Access Journals (Sweden)

Cvetanoski Radomir

2017-01-01

Full Text Available Pipe connections allow interconnection of individual pipes to obtain pipeline and pipe connection with the equipment and their connection to the valve. The pipe connector should have the same strength of the pipe, impermeability and possibility of easy assembly and disassembly. Connecting of pipes of such construction is carried out by welding due to the work in conditions of maximum operating pressures and temperatures. The pipes can be joined at the ends. When welding the pipe lines should take into account the condition that the flow resistance of the fluid must to be as small as possible. Therefore, special preparation for pipe welding it is often necessary, as well as for the welding processes itself not to have any internal height differences of the joint or unevenness of the internal diameter of the pipe.

75 FR 69050 - Certain Seamless Carbon and Alloy Steel Standard, Line, and Pressure Pipe From the People's...

Science.gov (United States)

2010-11-10

... amended (``the Act''), that an industry in the United States is threatened with material injury by reason... case is based on the threat of material injury and is not accompanied by a finding that injury would... Alloy Steel Standard, Line, and Pressure Pipe From the People's Republic of China: Amended Final...

MAXIMUM AIR SUCTION INTO HORIZONTAL OPEN ENDED CYLINDRICAL LOUVERED PIPE

Directory of Open Access Journals (Sweden)

SAMEER RANJAN SAHU

2017-02-01

Full Text Available The main approach behind the present numerical investigation is to estimate the mass flow rate of air sucked into a horizontal open-ended louvered pipe from the surrounding atmosphere. The present numerical investigation has been performed by solving the conservation equations for mass, momentum and energy along with two equation based k-ɛ model for a louvered horizontal cylindrical pipe by finite volume method. It has been found from the numerical investigation that mass suction rate of air into the pipe increases with increase in louvered opening area and the number of nozzles used. Keeping other parameters fixed, for a given mass flow rate there exists an optimum protrusion of nozzle for highest mass suction into the pipe. It was also found from the numerical investigation that increasing the pipe diameter the suction mass flow rate of air was increased.

Heat pipes with variable thermal conductance property for space applications

Energy Technology Data Exchange (ETDEWEB)

Kravets, V.; Alekseik, Ye.; Alekseik, O.; Khairnasov, S. [National Technical University of Ukraine, Kyiv (Ukraine); Baturkin, V.; Ho, T. [Explorationssysteme RY-ES, Bremen (Germany); Celotti, L. [Active Space Technologies GmbH, Berlin (Germany)

2017-06-15

The activities presented in this paper demonstrate a new approach to provide passive thermal control using heat pipes, as demonstrated on the electronic unit of DLR’s MASCOT lander, which embarked on the NEA sample return mission Hayabusa 2 (JAXA). The focus is on the development and testing of heat pipes with variable thermal conductance in a predetermined temperature range. These heat pipes act as thermal switches. Unlike standard gasloaded heat pipes and thermal-diode heat pipes construction of presented heat pipes does not include any additional elements. Copper heat pipes with metal fibrous wicks were chosen as baseline design. We obtained positive results by choosing the heat carrier and structural parameters of the wick (i.e., pore diameter, porosity, and permeability). The increase in the thermal conductivity of the heat pipes from 0.04 W/K to 2.1 W/K was observed in the temperature range between −20 °C and +55 °C. Moreover, the heat pipes transferred the predetermined power of not less than 10 W within the same temperature range. The heat pipes have been in flight since December 2014, and the supporting telemetry data were obtained in September 2015. The data showed the nominal operation of the thermal control system.

Transient heat pipe investigations for space power systems

International Nuclear Information System (INIS)

Merrigan, M.A.; Keddy, E.S.; Sena, J.T.

1985-01-01

A 4-meter long, high temperature, high power, molybdenum-lithium heat pipe has been fabricated and tested in transient and steady state operation at temperatures to 1500 K. Maximum power throughput during the tests was approximately 37 kW/cm 2 for the 1.4 cm diameter vapor space of the annular wick heat pipe. The evaporator flux density for the tests was 150.0 W/cm 2 over a length of 40 cm. Condenser length was approximately 3.0 m with radiant heat rejection from the condenser to a coaxial, water cooled radiation calorimeter. A variable radiation shield, controllable from the outside of the vacuum enclosure, was used to vary the load on the heat pipe during the tests. 1 ref., 9 figs

Pipe-CUI-profiler: a portable nucleonic system for detecting corrosion under insulation (CUI) of steel pipes

International Nuclear Information System (INIS)

Jaafar Abdullah; Rasif Mohd Zain; Roslan Yahya

2003-01-01

Corrosion under insulation (CUI) on the external wall of steel pipes is a common problem in many types of industrial plants. This is mainly due to the presence of moisture or water in the insulation materials. A portable nucleonic system that can be used to detect CUI without the need to remove the insulation materials, has been developed. The system is based on dual-beam gamma-ray absorption technique. It is designed to inspect pipes of internal diameter 50, 65, 80, 90, 100 and 150 mm. Pipeline of these sizes with aluminium or thin steel sheathing, containing fibre-glass or calcium silicate insulation to thicknesses of 25, 40 and 50 mm can be inspected. The system has proven to be a safe, fast and effective method of inspecting insulated pipes. This paper describes the new nucleonic system that has been developed. This paper describes the basic principle of the system and outlines its performance. (Author)

Development and design of a UF6 gas pressure meter for 42 mm pipes

International Nuclear Information System (INIS)

Peters, E.; Wichers, V.A.

1995-08-01

X-ray fluorescence (XRF) has proved to be a feasible method of measuring the pressure of UF 6 -gas for enrichment verification purposes. Complications will arise under extreme conditions, such as high uranium deposit to gas ratios, pipe diameters smaller than 40 mm and pressures less than 100 Pa. This report presents an experimental analysis of the XRF method for design worst case conditions for 42 outer diameter cascade-to-header pipes and the development of a prototype measurement device. This prototype is integrated in the construction of the enrichment verification system. (orig.)

Mechanism for in-pipe inspection; Dispositivo para inspecao de dutos

Energy Technology Data Exchange (ETDEWEB)

Freitas, Gustavo Medeiros; Dutra, Max Suell [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

2008-07-01

The internal inspection of pipes is becoming a routine activity thanks to their importance on transportation of substances such as oil and natural gas. This paper addresses a mechanism capable of working inside pipes of different diameters that may present extreme curves and inclinations. The mechanism is composed of modules with devices that provide adjustable contact with the duct, using wheels on the contact points. The robot moves inside the pipe creating a virtual spindle. For that, two parts are used: the first one, guided along the pipe by a set of wheels, moves parallel to the axis of the pipe; the second part is attached to a motor. The motor rotation forces the mechanism to follow a helical motion, with tilted wheels rotating about the axis of the pipe. Each adjustable contact device works like a lever, pressing the wheel against the pipe. The base of the device can be actively rotated, modifying the angle of the wheel in relation to the pipe (equivalent to the step of the spindle), permitting the motion of the system in both directions, with specific velocity. According to the applied angle, the robot changes the relation between torque and displacement velocity. (author)

LABORATORY EVALUATION ON PERFORMANCE OF GLASS FIBER REINFORCED PLASTIC MORTAR PIPE CULVERTS

Directory of Open Access Journals (Sweden)

Huawang Shi

2018-04-01

Full Text Available This paper investigated the performance and behaviour of glass fiber reinforced plastic mortar (FRPM pipes under different loading conditions. FRPM pipes with inner diameter of 1500 mm were prefabricated in factory. Mechanics performance testing (ring and axial compressive strength and elastic modulus, stiffness and fatigue test were carried out in laboratory. Ring stiffness test provided pipe stiffness (PS which is a function of geometry and material type of pipe through parallel plate loading test (PPLT. The fatigue test and micro-structure measure method were used to evaluate the durability effects of FRPM under repeated compression load. Results indicated that FRPM pipes had better mechanic performances as the road culverts under soils. It may be helpful for the design and construction of FRPM culverts.

Attempts to isolate a horizontal high diameter (300 mm nominal diameter) pipeline with an ice plug at minimum water flow and without water flow

International Nuclear Information System (INIS)

Corbescu, B.; Gyongyosi, T.; Puiu, D.; Panaitescu, V. N.

2016-01-01

The ice plug isolation technique used for high diameter horizontal pipes is used for repair and maintenance activities on hydraulic installations that use liquid working agents. These techniques do not require shutting down the entire plant. The ice plug development inside the pipe requires using custom specialized equipment for each individual application. This paper briefly describes the experimental technological facilities used for conducting the experiments and highlights the important aspects in an experiment conducted on a horizontal NPS 12 testing section running demineralized water followed by the result analysis and conclusions. The paper is dedicated to specialists working in research and technological engineering. (authors)

Seamless and secure communications over heterogeneous wireless networks

CERN Document Server

Cao, Jiannong

2014-01-01

This brief provides an overview of the requirements, challenges, design issues and major techniques for seamless and secure communications over heterogeneous wireless networks. It summarizes and provides detailed insights into the latest research on handoff management, mobility management, fast authentication and security management to support seamless and secure roaming for mobile clients. The reader will also learn about the challenges in developing relevant technologies and providing ubiquitous Internet access over heterogeneous wireless networks. The authors have extensive experience in im

Manufacturing and use of spiral welded pipes for high pressure service : state of the art

Energy Technology Data Exchange (ETDEWEB)

Knoop, F.M.; Sommer, B. [Salzgitter GroBrohre GmbH, Salzgitter (Germany)

2004-07-01

This paper provided details of an improved helical seam 2-step (HTS) manufacturing process used to produce spiral welded large diameter pipes for high pressure transmission pipelines. During the process, pipe forming is combined with continuous tack welding and internal and external submerged arc welding at separate welding stations. The pipe forming unit consists of a 3 roll bending system with an outside roller cage used to guarantee the roundness of the pipe. The converging strip edges of the pipe are joined using a continuous shielded arc tack weld. Tack welding is done automatically with a laser-guided weld head. Run-out angles are adjusted by an automatic gap control system. The formed and tack-welded pipes are then fed to computer-controlled welding stations for final welding, where each pipe is rotated with a precise screw-like motion. The same welding materials used for the helical seam are used for the skelp end welding. The process offers more precise root gap control, as well as improved pipe geometry. Use of the process has also increased production rates and improved weld stability. The dimensions of the spiral-weld pipes are adjustable so that any diameter can be produced from a base material of the same width. The pipes can also be coated externally with fusion-bonded epoxy or 3-layer polyethylene/polypropylene. It was concluded that the process is being further refined to support the use of HTS pipes in high-pressure pipelines. New nondestructive testing techniques used to assess the performance of the line pipes were presented, as well as the results from hot and cold bending tests, field weldability trials, and tests related to the safety of spiral pipes. 16 refs., 2 tabs., 12 figs.

Pulsatile turbulent flow through pipe bends at high Dean and Womersley numbers

Science.gov (United States)

Kalpakli, Athanasia; Örlü, Ramis; Tillmark, Nils; Alfredsson, P. Henrik

2011-12-01

Turbulent pulsatile flows through pipe bends are prevalent in internal combustion engine components which consist of bent pipe sections and branching conduits. Nonetheless, most of the studies related to pulsatile flows in pipe bends focus on incompressible, low Womersley and low Dean number flows, primarily because they aim in modeling blood flow, while internal combustion engine related flows have mainly been addressed in terms of integral quantities and consist of single point measurements. The present study aims at bridging the gap between these two fields by means of time-resolved stereoscopic particle image velocimetry measurements in a pipe bend with conditions that are close to those encountered in exhaust manifolds. The time/phase-resolved three-dimensional cross-sectional flow-field 3 pipe diameters downstream the pipe bend is captured and the interplay between different secondary motions throughout a pulse cycle is discussed.

Pulsatile turbulent flow through pipe bends at high Dean and Womersley numbers

International Nuclear Information System (INIS)

Kalpakli, Athanasia; Örlü, Ramis; Tillmark, Nils; Alfredsson, P Henrik

2011-01-01

Turbulent pulsatile flows through pipe bends are prevalent in internal combustion engine components which consist of bent pipe sections and branching conduits. Nonetheless, most of the studies related to pulsatile flows in pipe bends focus on incompressible, low Womersley and low Dean number flows, primarily because they aim in modeling blood flow, while internal combustion engine related flows have mainly been addressed in terms of integral quantities and consist of single point measurements. The present study aims at bridging the gap between these two fields by means of time-resolved stereoscopic particle image velocimetry measurements in a pipe bend with conditions that are close to those encountered in exhaust manifolds. The time/phase-resolved three-dimensional cross-sectional flow-field 3 pipe diameters downstream the pipe bend is captured and the interplay between different secondary motions throughout a pulse cycle is discussed.

A diagnosis of piping corrosion using image processor

International Nuclear Information System (INIS)

Yotsusuji, Mitoshi

1999-01-01

There are many piping installed to transfer various type of fluid in the petro-refinal, petrochemical plant and so on. These piping are used in corrosion and erosion environment by internal fluids and will get the localized wastage with various form such as a pitting corrosion and a grooving. Therefore, the maintenance inspection to detect shch wastage at the early stage should be necessary not only for effective operation but for safety control too. By introducing FCR system equipped with imaging plate (IP) which have high sensitivity and high resolution using the special fluorescent substance instead of the usual industry X-ray film, it is possible to measure the relative penetrated radiation intensity of interesting areas with the correct value of digital counts. Engaging to this technique, we developed the method to judge the wastage depth of plane area on large diameter piping, as well as evaluate the cross section of the pipe to compare the relative penetrated radiation intensity of wastage parts with sound area. (author)

Numerical Analysis on the Compressible Flow Characteristics of Supersonic Jet Caused by High-Pressure Pipe Rupture Using CFD

Energy Technology Data Exchange (ETDEWEB)

Jung, Jong-Kil; Yoon, Jun-Kyu [Gachon Univ., Sungnam (Korea, Republic of); Kim, Kwang-Chu [KEPCO-E& C, Kimchun (Korea, Republic of)

2017-10-15

A rupture in a high-pressure pipe causes the fluid in the pipe to be discharged in the atmosphere at a high speed resulting in a supersonic jet that generates the compressible flow. This supersonic jet may display complicated and unsteady behavior in general . In this study, Computational Fluid Dynamics (CFD) analysis was performed to investigate the compressible flow generated by a supersonic jet ejected from a high-pressure pipe. A Shear Stress Transport (SST) turbulence model was selected to analyze the unsteady nature of the flow, which depends upon the various gases as well as the diameter of the pipe. In the CFD analysis, the basic boundary conditions were assumed to be as follows: pipe of diameter 10 cm, jet pressure ratio of 5, and an inlet gas temperature of 300 K. During the analysis, the behavior of the shockwave generated by a supersonic jet was observed and it was found that the blast wave was generated indirectly. The pressure wave characteristics of hydrogen gas, which possesses the smallest molecular mass, showed the shortest distance to the safety zone. There were no significant difference observed for nitrogen gas, air, and oxygen gas, which have similar molecular mass. In addition, an increase in the diameter of the pipe resulted in the ejected impact caused by the increased flow rate to become larger and the zone of jet influence to extend further.

Development of non-destructive diagnosis technology for pipe internal in thermal power plants based on robotics

Energy Technology Data Exchange (ETDEWEB)

Kim, Seungho; Kim, Changhoi; Seo, Yongchil; Lee, Sunguk; Jung, Seungho; Jung, Seyoung

2011-11-15

The Pipelines of power plants may have tiny crack by corrosion. Pipe safety inspection should be performed periodically and non-periodically to ensure their safety and integrity. It is difficult to inspection pipes inside defect since pipes of power plant is covered thermal insulation material. Normally pipes inspection was performed part of pipes on outside. A mobile robot was developed for the inspection of pipe of 100 mm inside diameter. The robot is adopted screw type drive mechanism in order to move vertical, horizontal pipes inside. The multi-laser and camera module, which is mounted in front of the robot, captures a sequence of 360 degree shapes of the inner surface of a pipe. The 3D inner shape of pipe is reconstructed from a multi laser triangulation techniques for the inspection of pipes.

Turbulent flow in a partially filled pipe

Science.gov (United States)

Ng, Henry; Cregan, Hope; Dodds, Jonathan; Poole, Robert; Dennis, David

2017-11-01

Turbulent flow in a pressure driven pipe running partially full has been investigated using high-speed 2D-3C Stereoscopic Particle Imaging Velocimetry. With the field-of-view spanning the entire pipe cross section we are able to reconstruct the full three dimensional quasi-instantaneous flow field by invoking Taylor's hypothesis. The measurements were carried out over a range of flow depths at a constant Reynolds number based on hydraulic diameter and bulk velocity of Re = 32 , 000 . In agreement with previous studies, the ``velocity dip'' phenomenon, whereby the location of the maximum streamwise velocity occurs below the free surface was observed. A mean flow secondary current is observed near the free surface with each of the counter-rotating rollers filling the half-width of the pipe. Unlike fully turbulent flow in a rectangular open channel or pressurized square duct flow where the secondary flow cells appear in pairs about a corner bisector, the mean secondary motion observed here manifests only as a single pair of vortices mirrored about the pipe vertical centreline.

Rotating optical geometry sensor for inner pipe-surface reconstruction

Science.gov (United States)

Ritter, Moritz; Frey, Christan W.

2010-01-01

The inspection of sewer or fresh water pipes is usually carried out by a remotely controlled inspection vehicle equipped with a high resolution camera and a lightning system. This operator-oriented approach based on offline analysis of the recorded images is highly subjective and prone to errors. Beside the subjective classification of pipe defects through the operator standard closed circuit television (CCTV) technology is not suitable for detecting geometrical deformations resulting from e.g. structural mechanical weakness of the pipe, corrosion of e.g. cast-iron material or sedimentations. At Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB) in Karlsruhe, Germany, a new Rotating Optical Geometry Sensor (ROGS) for pipe inspection has been developed which is capable of measuring the inner pipe geometry very precisely over the whole pipe length. This paper describes the developed ROGS system and the online adaption strategy for choosing the optimal system parameters. These parameters are the rotation and traveling speed dependent from the pipe diameter. Furthermore, a practicable calibration methodology is presented which guarantees an identification of the several internal sensor parameters. ROGS has been integrated in two different systems: A rod based system for small fresh water pipes and a standard inspection vehicle based system for large sewer Pipes. These systems have been successfully applied to different pipe systems. With this measurement method the geometric information can be used efficiently for an objective repeatable quality evaluation. Results and experiences in the area of fresh water pipe inspection will be presented.

Development and design of a UF{sub 6} gas pressure meter for 42 mm pipes

Energy Technology Data Exchange (ETDEWEB)

Peters, E.; Wichers, V.A.

1995-08-01

X-ray fluorescence (XRF) has proved to be a feasible method of measuring the pressure of UF{sub 6}-gas for enrichment verification purposes. Complications will arise under extreme conditions, such as high uranium deposit to gas ratios, pipe diameters smaller than 40 mm and pressures less than 100 Pa. This report presents an experimental analysis of the XRF method for design worst case conditions for 42 outer diameter cascade-to-header pipes and the development of a prototype measurement device. This prototype is integrated in the construction of the enrichment verification system. (orig.).

Simulation of boiling flow in evaporator of separate type heat pipe with low heat flux

International Nuclear Information System (INIS)

Kuang, Y.W.; Wang, Wen; Zhuan, Rui; Yi, C.C.

2015-01-01

Highlights: • A boiling flow model in a separate type heat pipe with 65 mm diameter tube. • Nucleate boiling is the dominant mechanism in large pipes at low mass and heat flux. • The two-phase heat transfer coefficient is less sensitive to the total mass flux. - Abstract: The separate type heat pipe heat exchanger is considered to be a potential selection for developing passive cooling spent fuel pool – for the passive pressurized water reactor. This paper simulates the boiling flow behavior in the evaporator of separate type heat pipe, consisting of a bundle of tubes of inner diameter 65 mm. It displays two-phase characteristic in the evaporation section of the heat pipe working in low heat flux. In this study, the two-phase flow model in the evaporation section of the separate type heat pipe is presented. The volume of fluid (VOF) model is used to consider the interaction between the ammonia gas and liquid. The flow patterns and flow behaviors are studied and the agitated bubbly flow, churn bubbly flow are obtained, the slug bubble is likely to break into churn slug or churn froth flow. In addition, study on the heat transfer coefficients indicates that the nucleate boiling is the dominant mechanism in large pipes at low mass and heat flux, with the heat transfer coefficient being less sensitive to the total mass flux

Alpha detection in pipes using an inverting membrane scintillator

International Nuclear Information System (INIS)

Kendrick, D.T.; Cremer, C.D.; Lowry, W.; Cramer, E.

1995-01-01

Characterization of surface alpha emitting contamination inside enclosed spaces such as piping systems presents an interesting radiological measurement challenge. Detection of these alpha particles from the exterior of the pipe is impossible since the alpha particles are completely absorbed by the pipe wall. Traditional survey techniques, using hand-held instruments, simply can not be used effectively inside pipes. Science and Engineering Associates, Inc. is currently developing an enhancement to its Pipe Explorer trademark system that will address this challenge. The Pipe Explorer trademark uses a unique sensor deployment method where an inverted tubular membrane is propagated through complex pipe runs via air pressure. The inversion process causes the membrane to fold out against the pipe wall, such that no part of the membrane drags along the pipe wall. This deployment methodology has been successfully demonstrated at several DOE sites to transport specially designed beta and gamma scintillation detectors into pipes ranging in length up to 250 ft. The measurement methodology under development overcomes the limitations associated with conventional hand-held survey instruments by remotely emplacing an alpha scintillator in direct contact with the interior pipe surface over the entire length to be characterized. This is accomplished by incorporating a suitable scintillator into the otherwise clear membrane material. Alpha particles emitted from the interior pipe surface will intersect the membrane, resulting in the emission of light pulses from the scintillator. A photodetector, towed by the inverting membrane, is used to count these light pulses as a function of distance into the pipe, thereby producing a log of the surface alpha contamination levels. It is anticipated that the resulting system will be able to perform measurements in pipes as small as two inches in diameter, and several hundred feet in length

Pipe Penetrating Radar: a New Tool for the Assessment of Critical Infrastructure

Science.gov (United States)

Ekes, C.; Neducz, B.

2012-04-01

This paper describes the development of Pipe Penetrating Radar (PPR), the underground in-pipe application of GPR, a non-destructive testing method that can detect defects and cavities within and outside mainline diameter (>18 in / 450mm) non-metallic (concrete, PVC, HDPE, etc.) underground pipes. The method uses two or more high frequency GPR antennae carried by a robot into underground pipes. The radar data is transmitted to the surface via fibre optic cable and is recorded together with the output from CCTV (and optionally sonar and laser). Proprietary software analyzes the data and pinpoints defects or cavities within and outside the pipe. Thus the testing can identify existing pipe and pipe bedding symptoms that can be addressed to prevent catastrophic failure due to sinkhole development and can provide useful information about the remaining service life of the pipe. The key innovative aspect is the unique ability to map pipe wall thickness and deterioration including cracks and voids outside the pipe, enabling accurate predictability of needed intervention or the timing of replacement. This reliable non-destructive testing method significantly impacts subsurface infrastructure condition based asset management by supplying previously unattainable measurable conditions. Keywords: pipe penetrating radar (PPR), ground penetrating radar (GPR), pipe inspection, concrete deterioration, municipal engineering

LWR primary coolant pipe rupture test rig

International Nuclear Information System (INIS)

Yoshitoshi, Shyoji

1978-01-01

The rupture test rig for primary coolant pipes is constructed in the Japan Atomic Energy Research Institute to verify the reliability of the primary coolant pipes for both PWRs and BWRs. The planned test items consisted of reaction force test, restraint test, whip test, jet test and continuous release test. A pressure vessel of about 4 m 3 volume, a circulating pump, a pressurizer, a heater, an air cooler and the related instrumentation and control system are included in this test rig. The coolant test condition is 160 kg/cm 2 g, 325 deg C for PWR test, and 70 kg/cm 2 g, saturated water and steam for BWR test, 100 ton of test load for the ruptured pipe bore of 8B Schedule 160, and 20 lit/min. discharge during 20 h for continuous release of coolant. The maximum pit internal pressure was estimated for various pipe diameters and time under the PWR and BWR conditions. The spark rupturing device was adopted for the rupture mechanics in this test rig. The computer PANAFACOM U-300 is used for the data processing. This test rig is expected to operate in 1978 effectively for the improvement of reliability of LWR primary coolant pipes. (Nakai, Y.)

Durability and Reliability of Large Diameter HDPE Pipe for Water Main Applications (Web Report 4485)

Science.gov (United States)

Research validates HDPE as a suitable material for use in municipal piping systems, and more research may help users maximize their understanding of its durability and reliability. Overall, corrosion resistance, hydraulic efficiency, flexibility, abrasion resistance, toughness, f...

76 FR 39850 - Seamless Refined Copper Pipe and Tube From Mexico: Notice of Initiation of Antidumping Duty New...

Science.gov (United States)

2011-07-07

... and Tube From Mexico and the People's Republic of China: Antidumping Duty Orders and Amended Final... copper pipe and tube from Mexico exported by GD, for the period November 22, 2010, through April 30, 2011... and Tube From Mexico: Notice of Initiation of Antidumping Duty New Shipper Review AGENCY: Import...

Severe slugging in gas-liquid two-phase pipe flow

NARCIS (Netherlands)

Malekzadeh, R.

2012-01-01

transportation facilities. In an offshore oil and gas production facility, pipeline-riser systems are required to transport two-phase hydrocarbons from subsurface oil and gas wells to a central production platform. Severe slugs reaching several thousands pipe diameters may occur when transporting

The effects of cyclic and dynamic loading on the fracture resistance of nuclear piping steels. Technical report, October 1992--April 1996

Energy Technology Data Exchange (ETDEWEB)

Rudland, D.L.; Brust, F.; Wilkowski, G.M.

1996-12-01

This report presents the results of the material property evaluation efforts performed within Task 3 of the IPIRG-2 Program. Several related investigations were conducted. (1) Quasi-static, cyclic-load compact tension specimen experiments were conducted using parameters similar to those used in IPIRG-1 experiments on 6-inch nominal diameter through-wall-cracked pipes. These experiments were conducted on a TP304 base metal, an A106 Grade B base metal, and their respective submerged-arc welds. The results showed that when using a constant cyclic displacement increment, the compact tension experiments could predict the through-wall-cracked pipe crack initiation toughness, but a different control procedure is needed to reproduce the pipe cyclic crack growth in the compact tension tests. (2) Analyses conducted showed that for 6-inch diameter pipe, the quasi-static, monotonic J-R curve can be used in making cyclic pipe moment predictions; however, sensitivity analyses suggest that the maximum moments decrease slightly from cyclic toughness degradation as the pipe diameter increases. (3) Dynamic stress-strain and compact tension tests were conducted to expand on the existing dynamic database. Results from dynamic moment predictions suggest that the dynamic compact tension J-R and the quasi-static stress-strain curves are the appropriate material properties to use in making dynamic pipe moment predictions.

The effects of cyclic and dynamic loading on the fracture resistance of nuclear piping steels. Technical report, October 1992--April 1996

International Nuclear Information System (INIS)

Rudland, D.L.; Brust, F.; Wilkowski, G.M.

1996-12-01

This report presents the results of the material property evaluation efforts performed within Task 3 of the IPIRG-2 Program. Several related investigations were conducted. (1) Quasi-static, cyclic-load compact tension specimen experiments were conducted using parameters similar to those used in IPIRG-1 experiments on 6-inch nominal diameter through-wall-cracked pipes. These experiments were conducted on a TP304 base metal, an A106 Grade B base metal, and their respective submerged-arc welds. The results showed that when using a constant cyclic displacement increment, the compact tension experiments could predict the through-wall-cracked pipe crack initiation toughness, but a different control procedure is needed to reproduce the pipe cyclic crack growth in the compact tension tests. (2) Analyses conducted showed that for 6-inch diameter pipe, the quasi-static, monotonic J-R curve can be used in making cyclic pipe moment predictions; however, sensitivity analyses suggest that the maximum moments decrease slightly from cyclic toughness degradation as the pipe diameter increases. (3) Dynamic stress-strain and compact tension tests were conducted to expand on the existing dynamic database. Results from dynamic moment predictions suggest that the dynamic compact tension J-R and the quasi-static stress-strain curves are the appropriate material properties to use in making dynamic pipe moment predictions

POSSIBILITIES OF THE USE OF GRP PIPING IN THE CONSTRUCTION AND RECONSTRUCTION OF ENGINEERING NETWORKS

Directory of Open Access Journals (Sweden)

ikitina Irina Nikolaevna

2015-12-01

Full Text Available Today in modern construction new technologies and materials are used for the manufacture of pipelines for water supply and sanitation. They are supposed to operate for at least 50 years. Unlike plastic pipes, fiberglass ones may be made of larger sizes — up to 3700 mm in diameter. They are produced using the technology of optical fiber winding, which is carried out according to modern international standards of quality. The basic raw materials — fiberglass and resin — are produced in Russia, but their production is limited, so they are purchased abroad, which increases the cost of manufacture of this type of piping. However, due to the necessity of laying pipelines of large diameter, which cannot be made with plastic pipes, the manufacture of GRP pipes will increase. The experience of laying and constructing this type of pipelines, for example, in the areas of hot water supply allows concluding that they are able to withstand the temperatures of up to 150 °C, while their weight is four times less than the weight of steel pipes (they are easily installed with the help of small lifting equipment and by a team of six people. It should be noted that the use of fiberglass pipes helps to reduce the costs of system operation, because this type of piping is not subject to corrosion and encrustation of the inner surface, since it has a low level of roughness, which, for example, is 0.013 for a steel pipe, and 0.01 for fiberglass pipe. Thus, it is not necessary to put protective corrosion-resistant coatings and to provide an expensive protection against electrochemical corrosion. Piping made of fiberglass pipes can be designed as underground, above-ground with stacking or raised on poles. It is possible to combine these options.

Study of Strain-Stress Behavior of Non-Pressure Reinforced Concrete Pipes Used in Road Building

Science.gov (United States)

Rakitin, B. A.; Pogorelov, S. N.; Kolmogorova, A. O.

2017-11-01

The article contains the results of the full-scale tests performed for special road products - large-diameter non-pressure concrete pipes reinforced with a single space cylindrical frame manufactured with the technology of high-frequency vertical vibration molding with an immediate demolding. The authors studied the change in the strain-stress behavior of reinforced concrete pipes for underground pipeline laying depending on their laying depth in the trench and the transport load considering the properties of the surrounding ground mass. The strain-stress behavior of the reinforced concrete pipes was evaluated using the strain-gauge method based on the application of active resistance strain gauges. Based on the completed research, the authors made a conclusion on the applicability of a single space frame for reinforcement of large-diameter non-pressure concrete pipes instead of a double frame which allows one to significantly reduce the metal consumption for the production of one item. As a result of the full-scale tests of reinforced concrete pipes manufactured by vertical vibration molding, the authors obtained new data on the deformation of a pipeline cross-section depending on the placement of the transport load with regard to the axis.

Heat transfer characteristics and operation limit of pressurized hybrid heat pipe for small modular reactors

International Nuclear Information System (INIS)

Kim, Kyung Mo; Bang, In Cheol

2017-01-01

Highlights: • Thermal performances and operation limits of hybrid heat pipe were experimentally studied. • Models for predicting the operation limit of the hybrid heat pipe was developed. • Non-condensable gas affected heat transfer characteristics of the hybrid heat pipe. - Abstract: In this paper, a hybrid heat pipe is proposed for use in advanced nuclear power plants as a passive heat transfer device. The hybrid heat pipe combines the functions of a heat pipe and a control rod to simultaneously remove the decay heat generated from the core and shutdown the reactor under accident conditions. Thus, the hybrid heat pipe contains a neutron absorber in the evaporator section, which corresponds to the core of the reactor pressure vessel. The presence of the neutron absorber material leads to differences in the heated diameter and hydraulic diameter of the heat pipe. The cross-sectional areas of the vapor paths through the evaporator, adiabatic, and condenser sections are also different. The hybrid heat pipe must operate in a high-temperature, high-pressure environment to remove the decay heat. In other words, the operating pressure must be higher than those of the commercially available thermosyphons. Hence, the thermal performances, including operation limit of the hybrid heat pipe, were experimentally studied in the operating pressure range of 0.2–20 bar. The operating pressure of the hybrid heat pipe was controlled by charging the non-condensable gas which is unused method to achieve the high saturation pressure in conventional thermosyphons. The effect of operating pressure on evaporation heat transfer was negligible, while condensation heat transfer was affected by the amount of non-condensable gas in the test section. The operation limit of the hybrid heat pipe increased with the operating pressure. Maximum heat removal capacity of the hybrid heat pipe was up to 6 kW which is meaningful value as a passive decay heat removal device in the nuclear power

Development and Evaluation of Compact Robot Imitating a Hermit Crab for Inspecting the Outer Surface of Pipes

Directory of Open Access Journals (Sweden)

Naoto Imajo

2015-01-01

Full Text Available Terrestrial hermit crabs which are a type of hermit crabs live on land, whereas typical hermit crabs inhabit the sea. They have an ability of climbing a tree vertically. Their claws allow them to hang on the tree. In this study, an outer-pipe inspection robot was developed. Its locomotion mechanism was developed in imitation of the terrestrial hermit crab’s claws. It is equipped with two rimless wheels. Each of the spokes is tipped with a neodymium magnet, which allows the robot to remain attached to even a vertical steel pipe. Moreover, the robot has a mechanism for adjusting the camber angle of the right and left wheels, allowing it to tightly grip pipes with different diameters. Experiments were conducted to check the performance of the robot using steel pipes with different diameters, placed horizontally, vertically, or obliquely. The robot attempted to move a certain distance along a pipe, and its success rate was measured. It was found that the robot could successfully travel along pipes with vertical orientations, although it sometimes fell from oblique or horizontal pipes. The most likely reason for this is identified and discussed. Certain results were obtained in laboratory. Further experiments in actual environment are required.

Germany [Summary country report on coordinated research project on development of protocols for corrosion and deposit evaluation in large diameter pipes by radiography

International Nuclear Information System (INIS)

2008-01-01

Full text: In the framework of the CRP, Germany provided certified stepped film density strips for the calibration of film densitometers. They were used by each participant in his own country to validate the density measurements made in the radiographs prepared from the test specimen. According to the working plan, BAM belongs to Group 2 (8 and 12 inch pipe diameter, Co 60 available). The necessary raw pipe material was ordered and the corresponding drawings for machining were prepared in 2003. Because of weight and handiness it was decided to cut each of the two pipes into 2 halves, i.e. one half with outer steps and the other half with inner steps. In this way, a total number of 4 pipes were produced. As material, steel St-52 was chosen, the maximum wall thickness was 26 mm. The film exposure was finalized in October 2003. As radiation source, Co 60 was used and, as detector, AGFA D7 films with front/back screens of 0.5 mm Fe. Two different inspection methods have been applied: tangential projection technique (TRT) for absolute wall thickness measurements and double wall penetration technique (DWT) for estimation of wall thickness differences in the pipe centre. The combination of Fe screens with AGFA D7 films gives an excellent image quality with very low noise, but needs about double exposure time as compared with Pb screens. After film exposure, the evaluation of the films started. Wall thicknesses and optical film densities have been measured according to the recommended procedures as agreed at the expert meetings. In parallel Excel data sheets were developed for easy data evaluation and for the comparison of results provided by the different participating countries. The final Excel sheets for data evaluation and data collection have been distributed to the other CRP participants at the end of 2003. All films have been digitized at BAM Berlin. The digitized films have been evaluated also by special software, developed together with BASF for the German

Fatigue evaluation of socket welded piping in nuclear power plant

International Nuclear Information System (INIS)

Vecchio, R.S.

1996-01-01

Fatigue failures in piping systems occur, almost without exception, at the welded connections. In nuclear power plant systems, such failures occur predominantly at the socket welds of small diameter piping ad fillet attachment welds under high-cycle vibratory conditions. Nearly all socket weld fatigue failures are identified by leaks which, though not high in volume, generally are costly due to attendant radiological contamination. Such fatigue cracking was recently identified in the 3/4 in. diameter recirculation and relief piping socket welds from the reactor coolant system (RCS) charging pumps at a nuclear power plant. Consequently, a fatigue evaluation was performed to determine the cause of cracking and provide an acceptable repair. Socket weld fatigue life was evaluated using S-N type fatigue life curves for welded structures developed by AASHTO and the assessment of an effective cyclic stress range adjacent to each socket weld. Based on the calculated effective tress ranges and assignment of the socket weld details to the appropriate AASHTO S-N curves, the socket weld fatigue lives were calculated and found to be in excellent agreement with the accumulated cyclic life to-date

Learning Analytics for Supporting Seamless Language Learning Using E-Book with Ubiquitous Learning System

Science.gov (United States)

Mouri, Kousuke; Uosaki, Noriko; Ogata, Hiroaki

2018-01-01

Seamless learning has been recognized as an effective learning approach across various dimensions including formal and informal learning contexts, individual and social learning, and physical world and cyberspace. With the emergence of seamless learning, the majority of the current research focuses on realizing a seamless learning environment at…

Numerical and experimental investigation of leaks in viscoelastic pressurized pipe flow

Directory of Open Access Journals (Sweden)

S. Meniconi

2013-02-01

Full Text Available This paper extends the analysis concerning the importance in numerical models of unsteady friction and viscoelasticity to transients in plastic pipes with an external flow due to a leak. In fact recently such a benchmarking analysis has been executed for the cases of a constant diameter pipe (Duan et al., 2010, a pipe with a partially closed in-line valve (Meniconi et al., 2012a, and a pipe with cross-section changes in series (Meniconi et al., 2012b. Tests are based on laboratory experiments carried out at the Water Engineering Laboratory (WEL of the University of Perugia, Italy, and the use of different numerical models. The results show that it is crucial to take into account the viscoelasticity to simulate the main characteristics of the examined transients.

TO SEW OR NOT TO SEW. SEAMLESS CLOTHES AND SEAMLESS APPEARANCE IN FASHION DESIGN

Directory of Open Access Journals (Sweden)

ANDOR Elena Corina

2015-05-01

Full Text Available At first glance clothes are obviously made by cutting and sewing. The textile fabric is cut in different shapes and reassembled by sewing in the wanted shape and volume. Sometimes the structures can be quite complex. The truth is that there are more ways of making clothes, as we can see looking back into the history of fashion. The progress of technology in textile industry offers also very interesting directions that we could not dream about some time ago. Observing carefully the economy of seams, their presence, absence or the suitable number can move us towards creative solutions that are relevant not only for the esthetic of a garment but also for the process of making clothes suggesting alternatives for the present situation and its important problems like sustainability. This paper is a survey of alternative ways in making clothes and highlights the relation between concept and practical issues. The starting point is seamless clothing and the natural fascination of the subject. Going further on this line we should consider that the absence of the seams in a garment is not the same with a seamless appearance. So, do we really need to sew our clothes?

Ad-hoc networking towards seamless communications

CERN Document Server

Gavrilovska, Liljana

2006-01-01

Ad-Hoc Networking Towards Seamless Communications is dedicated to an area that attracts growing interest in academia and industry and concentrates on wireless ad hoc networking paradigm. The persistent efforts to acquire the ability to establish dynamic wireless connections from anywhere to anyone with any device without prerequisite imbedded infrastructure move the communications boundaries towards ad-hoc networks. Recently, ad hoc networking has attracted growing interest due to advances in wireless communications, and developed framework for running IP based protocols. The expected degree of penetration of these networks will depend on the successful resolution of the key features. Ad-hoc networks pose many complex and open problems for researchers. Ad-Hoc Networking Towards Seamless Communications reveals the state-of-the-art in wireless ad-hoc networking and discusses some of the key research topics that are expected to promote and accelerate the commercial applications of these networks (e.g., MAC, rout...

APPLICATION OF STEEL PIPE PILE LOADING TESTS TO DESIGN VERIFICATION OF FOUNDATION OF THE TOKYO GATE BRIDGE

Science.gov (United States)

Saitou, Yutaka; Kikuchi, Yoshiaki; Kusakabe, Osamu; Kiyomiya, Osamu; Yoneyama, Haruo; Kawakami, Taiji

Steel sheet pipe pile foundations with large diameter steel pipe sheet pile were used for the foundation of the main pier of the Tokyo Gateway bridge. However, as for the large diameter steel pipe pile, the bearing mechanism including a pile tip plugging effect is still unclear due to lack of the practical examinations even though loading tests are performed on Trans-Tokyo Bay Highway. In the light of the foregoing problems, static pile loading tests both vertical and horizontal directions, a dynamic loading test, and cone penetration tests we re conducted for determining proper design parameters of the ground for the foundations. Design parameters were determined rationally based on the tests results. Rational design verification was obtained from this research.

Rupture hardware minimization in pressurized water reactor piping

International Nuclear Information System (INIS)

Mukherjee, S.K.; Ski, J.J.; Chexal, V.; Norris, D.M.; Goldstein, N.A.; Beaudoin, B.F.; Quinones, D.F.; Server, W.L.

1989-01-01

For much of the high-energy piping in light reactor systems, fracture mechanics calculations can be used to assure pipe failure resistance, thus allowing the elimination of excessive rupture restraint hardware both inside and outside containment. These calculations use the concept of leak-before-break (LBB) and include part-through-wall flaw fatigue crack propagation, through-wall flaw detectable leakage, and through-wall flaw stability analyses. Performing these analyses not only reduces initial construction, future maintenance, and radiation exposure costs, but also improves the overall safety and integrity of the plant since much more is known about the piping and its capabilities than would be the case had the analyses not been performed. This paper presents the LBB methodology applied a Beaver Valley Power Station- Unit 2 (BVPS-2); the application for two specific lines, one inside containment (stainless steel) and the other outside containment (ferrutic steel), is shown in a generic sense using a simple parametric matrix. The overall results for BVPS-2 indicate that pipe rupture hardware is not necessary for stainless steel lines inside containment greater than or equal to 6-in. (152-mm) nominal pipe size that have passed a screening criteria designed to eliminate potential problem systems (such as the feedwater system). Similarly, some ferritic steel line as small as 3-in. (76-mm) diameter (outside containment) can qualify for pipe rupture hardware elemination

Seamless Learning Environments in Higher Education with Mobile Devices and Examples

Science.gov (United States)

Marín, Victoria I.; Jääskelä, Päivikki; Häkkinen, Päivi; Juntunen, Merja; Rasku-Puttonen, Helena; Vesisenaho, Mikko

2016-01-01

The use of seamless learning environments that have the potential to support lifelong learning anytime and anywhere has become a reality. In this sense, many educational institutions have started to consider introducing seamless learning environments into their programs. The aim of this study is to analyze how various educational university…

Comparison of fracture toughness values from large-scale pipe system tests and C(T) specimens

International Nuclear Information System (INIS)

Olson, R.; Scott, P.; Marschall, C.; Wilkowski, G.

1993-01-01

Within the International Piping Integrity Research Group (IPIRG) program, pipe system experiments involving dynamic loading with intentionally circumferentially cracked pipe were conducted. The pipe system was fabricated from 406-mm (16-inch) diameter Schedule 100 pipe and the experiments were conducted at 15.5 MPa (2,250 psi) and 288 C (550 F). The loads consisted of pressure, dead-weight, thermal expansion, inertia, and dynamic anchor motion. Significant instrumentation was used to allow the material fracture resistance to be calculated from these large-scale experiments. A comparison of the toughness values from the stainless steel base metal pipe experiment of standard quasi-static and dynamic C(T) specimen tests showed the pipe toughness value was significantly lower than that obtained from C(T) specimens. It is hypothesized that the cyclic loading from inertial stresses in this pipe system experiment caused local degradation of the material toughness. Such effects are not considered in current LBB or pipe flaw evaluation criteria. 4 refs., 14 figs., 1 tab

Secondary pipe rupture at Mihama unit 3

International Nuclear Information System (INIS)

Hajime Ito; Takehiko Sera

2005-01-01

The secondary system pipe rupture occurred on August 9, 2004, while Mihama unit 3 was operating at the rated thermal power. The rupture took place on the condensate line-A piping between the No.4 LP heater and the deaerator, downstream of an orifice used for measuring the condensate flux. The pipe is made of carbon steel, and normally has 558.8 mm diameter and 10 mm thickness. The pipe wall had thinned to 0.4 mm at the point of minimum thickness. It is estimated that the disturbed flow of water downstream of the orifice caused erosion/corrosion and developed wall thinning, leading to a rupture at the thinnest section under internal pressure, about 1MPa. Observation of the pipe internal surface revealed a scale-like pattern typical in this kind of phenomenon. Eleven workers who were preparing for an annual outage that was to start from August 14 suffered burn injuries, of who five died. Since around 1975, we, Kansai Electric, have been checking pipe wall thickness while focusing on the thinning of carbon steel piping in the secondary system. Summarizing the results from such investigation and reviewing the latest technical knowledge including operating experience from overseas utilities, we compiled the pipe thickness management guideline for PWR secondary pipes, 1990. The pipe section that ruptured at the Mihama unit 3 should have been included within the inspection scopes according to the guideline but was not registered on the inspection list. It had not been corrected for almost thirty years. As the result, this pipe section had not been inspected even once since the beginning of the plant operation, 1976. It seems that the quality assurance and maintenance management had not functioned well regarding the secondary system piping management, although we were responsible for the safety of nuclear power plants as licensee. We will review the secondary system inspection procedure and also improve the pipe thickness management guideline. And also, we would replace

Development and performance of resistive seamless straw-tube gas chambers

International Nuclear Information System (INIS)

Takubo, Y.; Aoki, M.; Ishihara, A.; Ishii, J.; Kuno, Y.; Maeda, F.; Nakahara, K.; Nosaka, N.; Sakamoto, H.; Sato, A.; Terai, K.; Igarashi, Y.; Yokoi, T.

2005-01-01

A new straw-tube gas chamber which is made of seamless straw-tubes, instead of ordinary wound-type straw-tubes is developed. Seamless straw-tubes have various advantages over ordinary wound-type ones, in particular, in terms of mechanical strength and lesser wall thickness. Our seamless straw-tubes are fabricated to be resistive so that the hit positions along the straw axis can be read by cathode planes placed outside the straw-tube chambers, where the cathode strips run transverse to the straw axis. A beam test was carried out at KEK to study their performance. As a result of the beam test, the position resolution of the cathode strips of 220μm is achieved, and an anode position resolution of 112μm is also obtained

The effect of cyclic and dynamic loads on carbon steel pipe

International Nuclear Information System (INIS)

Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.

1996-02-01

This report presents the results of four 152-mm (6-inch) diameter, unpressurized, circumferential through-wall-cracked, dynamic pipe experiments fabricated from STS410 carbon steel pipe manufactured in Japan. For three of these experiments, the through-wall crack was in the base metal. The displacement histories applied to these experiments were a quasi-static monotonic, dynamic monotonic, and dynamic, cyclic (R = -1) history. The through-wall crack for the third experiment was in a tungsten-inert-gas weld, fabricated in Japan, joining two lengths of STS410 pipe. The displacement history for this experiment was the same history applied to the dynamic, cyclic base metal experiment. The test temperature for each experiment was 300 C (572 F). The objective of these experiments was to compare a Japanese carbon steel pipe material with US pipe material, to ascertain whether this Japanese steel was as sensitive to dynamic and cyclic effects as US carbon steel pipe. In support of these pipe experiments, quasi-static and dynamic, tensile and fracture toughness tests were conducted. An analysis effort was performed that involved comparing experimental crack initiation and maximum moments with predictions based on available fracture prediction models, and calculating J-R curves for the pipe experiments using the η-factor method

Residual stress measurement in 304 stainless steel weld overlay pipes

International Nuclear Information System (INIS)

Yen, H.J.; Lin, M.C.C.; Chen, L.J.

1996-01-01

Welding overlay repair (WOR) is commonly employed to rebuild piping systems suffering from intergranular stress corrosion cracking (IGSCC). To understand the effects of this repair, it is necessary to investigate the distribution of residual stresses in the welding pipe. The overlay welding technique must induce compressive residual stress at the inner surface of the welded pipe to prevent IGSCC. To understand the bulk residual stress distribution, the stress profile as a function of location within wall is examined. In this study the full destructive residual stress measurement technique -- a cutting and sectioning method -- is used to determine the residual stress distribution. The sample is type 304 stainless steel weld overlay pipe with an outside diameter of 267 mm. A pipe segment is cut from the circular pipe; then a thin layer is removed axially from the inner to the outer surfaces until further sectioning is impractical. The total residual stress is calculated by adding the stress relieved by cutting the section away to the stress relieved by axially sectioning. The axial and hoop residual stresses are compressive at the inner surface of the weld overlay pipe. Compressive stress exists not only at the surface but is also distributed over most of the pipe's cross section. On the one hand, the maximum compressive hoop residual stress appears at the pipe's inner surface. The thermal-mechanical induced crack closure from significant compressive residual stress is discussed. This crack closure can thus prevent IGSCC very effectively

Multiple-jet thermal mixing in a piping tee

International Nuclear Information System (INIS)

Lykoudis, P.S.; Hagar, R.C.

1979-01-01

Piping tees that are used to mix fluid streams at different temperatures are subjected to possibly severe thermal and mechanical stresses. There is reason to suspect that mixing in a piping tee could be improved by injecting the fluid streams into the tee through multiple jets. This paper reports the results of an experimental investigation of the effects of multiple-jet injection on mixing in a piping tee. The experimental work involves the measurement of the temperature fluctuation intensity with a hot-film sensor downstream of a simple 22.22-mm(7/8-in.)-diam tee with mixed multiple-jet injected hot and cold streams of water. The jets were provided by holes drilled in plates that partially blocked the inlet streams; 26 pairs of plates were investigated. The number of holes per plate varied from 1 to 51; the jet diameters ranged from 5 to 68% of the tee diameter. The inlet stream Reynolds number upstream of the jet plates was roughly 15 500 for each stream. The data indicated that the root mean square (rms) temperature fluctuation intensity measured at the tee outlet decreased dramatically as the jet plate cross-sectional area void fraction was decreased. When the jets emanating from the tee plates were misaligned, the reduction of the rms temperature fluctuation was not as high as when the jets were aligned. The rate of decay of the intensity downstream of the tee for most ofthe plates investigated was found to agree well with the -3/4 power decay law predicted by Corrsin's theory of scalar decay. However, unusual features in the intensity decay data were also observed, such as an increase of the intensity several diameters downstream before continuing to decay

Nonlinear piping damping and response predictions

International Nuclear Information System (INIS)

Severud, L.K.; Weiner, E.O.; Lindquist, M.R.; Anderson, M.J.; Wagner, S.E.

1986-10-01

The high level dynamic testing of four prototypic piping systems, used to provide benchmarks for analytical prediction comparisons, is overviewed. The size of pipe tested ranged from one-inch to six-inches in diameter and consisted of carbon steel or stainless steel material. Failure of the tested systems included progressive gross deformation or some combination of ratchetting-fatigue. Pretest failure predictions and post test comparisons using simplified elastic and elasto-plastic methods are presented. Detailed non-linear inelastic analyses are also shown, along with a typical ratchet-fatigue failure calculation. A simplified method for calculating modal equivalent viscous damping for snubbers and plastic hinges is also described. Conclusions are made regarding the applicability of the various analytical failure predictive methods and recommendations are made for future analytic and test efforts

Kerosene-water separation in T-junction with orientation upward branch with a 60° angle: Variation of diameter ratio

Science.gov (United States)

Puspitasari, Dewi; Indarto, Purnomo, Khasani

2016-06-01

Research on the T-junction is still underway for the flow of liquid-liquid (kerosene-water). Some research on the characteristics of kerosene-water separation was performed using T-junction oriented upward branch with a 60° angle. To observe the effect of diameters ratio on the phase separation that produced T-junction then made a test section with a horizontal pipe diameter 36 mm, while the side arm 36 mm diameter, 26 mm and 19 mm (diameters ratio of 1, 0.7 and 0.5) by using plexiglass pipe type. Based on experimental results and visualization of data flow in the test section, to the value obtained 60% water cut, the maximum separation efficiency of 94%, FK = 0.94 and FW = 0.001 with a diameter ratio of 1. For other diameter ratio of 0.7 and 0.5 respectively separation efficiency of 66%, FK = 1 and Fw = 0.34 for 0.7 and separation efficiency of 84%, FK = 1 and Fw = 0.16 for 0.5, the best value is obtained at a water cut 60% too. All the best conditions to achieve the above-stratified flow pattern.

Vibrational fatigue failures in short cantilevered piping with socket-welding fittings

International Nuclear Information System (INIS)

Smith, J.K.

1996-01-01

Approximately 80% of the vibrational fatigue failures in nuclear power plants have been caused by high cycle vibrational fatigue. Many of these failures have occurred in short, small bore (2 in. nominal diameter and smaller), unbraced, cantilevered piping with socket-welding fittings. The fatigue failures initiated in the socket welds. These failures have been unexpected, and have caused costly, unscheduled outages in some cases. In order to reduce the number of vibrational fatigue failures in these short cantilevered pipes, an acceleration based vibrational fatigue screening criteria was developed under Electric Power Research Institute (EPRI) sponsorship. In this paper, the acceleration based criteria will be compared to the results obtained from detailed dynamic modeling of a short, cantilevered pipe

BOA: Asbestos pipe-insulation removal robot system, Phase 2. Topical report, January--June 1995

Energy Technology Data Exchange (ETDEWEB)

Schempf, H.; Bares, J.E.

1995-06-01

This report explored the regulatory impact and cost-benefit of a robotic thermal asbestos pipe-insulation removal system over the current manual abatement work practice. The authors are currently in the second phase of a two-phase program to develop a robotic asbestos abatement system, comprised of a ground-based support system (including vacuum, fluid delivery, computing/electronics/power, and other subsystems) and several on-pipe removal units, each sized to handle pipes within a given diameter range. The intent of this study was to (i) aid in developing design and operational criteria for the overall system to maximize cost-efficiency, and (ii) to determine the commercial potential of a robotic pipe-insulation abatement system.

Radiation transmission type pipe wall thinning detection device and measuring instruments utilizing ionizing radiation

International Nuclear Information System (INIS)

Higashi, Yasuhiko

2009-01-01

We developed the device to detect thinning of pipe thorough heat insulation in Power Plant, etc, even while the plant is under operation. It is necessary to test many parts of many pipes for pipe wall thinning management, but it is difficult within a limited time of the routine test. This device consists of detector and radiation source, which can detect the pipe (less than 500 mm in external diameter, less than 50 mm in thickness) with 1.6%-reproducibility (in a few-minutes measurement), based on the attenuation rate. Operation is easy and effective without removing the heat insulation. We will expand this thinning detection system, and contribute the safety of the Plant. (author)

Experiments and calculations to leak openings and leak rates on typical piping components and systems

International Nuclear Information System (INIS)

Hoefler, A.; Grebner, H.

1992-01-01

Calculations of leak opening and leak rate for through cracks in piping components have been performed. The analyses are pre- or mostly post-calculations to experiments performed at the HDR facility under PWR operating conditions. Piping components under consideration are small diameter straight pipes with circumferential cracks, pipe bends with longitudinal or circumferential cracks and pipe branches with weldment cracks. The component are loaded by internal pressure and opening as well as closing bending moment. The finite element method and two-phase flow leak rate programs are used for the calculations. Results of the analyses are presented as J-integral values, crack opening displacements and areas and leak rates as well as comparisons to the experimental results. 6 refs., 16 figs., 2 tabs

Steel fiber reinforced concrete pipes: part 1: technological analysis of the mechanical behavior

Directory of Open Access Journals (Sweden)

A. D. de Figueiredo

Full Text Available This paper is the first part of an extensive work focusing the technological development of steel fiber reinforced concrete pipes (FRCP. Here is presented and discussed the experimental campaign focusing the test procedure and the mechanical behavior obtained for each of the dosages of fiber used. In the second part ("Steel fiber reinforced concrete pipes. Part 2: Numerical model to simulate the crushing test", the aspects of FRCP numerical modeling are presented and analyzed using the same experimental results in order to be validated. This study was carried out trying to reduce some uncertainties related to FRCP performance and provide a better condition to the use of these components. In this respect, an experimental study was carried out using sewage concrete pipes in full scale as specimens. The diameter of the specimens was 600 mm, and they had a length of 2500 mm. The pipes were reinforced with traditional bars and different contents of steel fibers in order to compare their performance through the crushing test. Two test procedures were used in that sense. In the 1st Series, the diameter displacement was monitored by the use of two LVDTs positioned at both extremities of the pipes. In the 2nd Series, just one LVDT is positioned at the spigot. The results shown a more rigidity response of the pipe during tests when the displacements were measured at the enlarged section of the socket. The fiber reinforcement was very effective, especially when low level of displacement was imposed to the FRCP. At this condition, the steel fibers showed an equivalent performance to superior class pipes made with traditional reinforced. The fiber content of 40 kg/m3 provided a hardening behavior for the FRCP, and could be considered as equivalent to the critical volume in this condition.

Fracture evaluation of an in-service piping flaw caused by microbiologically induced corrosion

International Nuclear Information System (INIS)

Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.; Rahman, S.

1996-01-01

A pipe fracture experiment was conducted on a section of 6-inch nominal diameter pipe which was degraded by microbiologically induced corrosion (MIC) at a circumferential girth weld. The pipe was a section of one of the service water piping systems to one of the emergency diesel generators at the Haddam Neck (Connecticut Yankee) plant. The experimental results will help validate future ASME Section XI pipe flaw evaluation criteria for other than Class 1 piping. A critical aspect of this experiment was an assessment of the degree of conservatism embodied in the ASME definition of flaw size. The ASME flaw size definition assumes a rectangular shaped, constant depth flaw with a depth equal to its maximum depth for its entire length. Since most service flaws are irregular in shape, this definition may be overly conservative. Results from several fracture prediction models are compared with the experimental results. These results show that, for this case, the ASME Appendix H criteria significantly underpredicted the experimental maximum moment, while other fracture prediction models provided good predictions when accurate pipe, weld and flaw dimensions were used

Shock resistance of composite material pipes

International Nuclear Information System (INIS)

Pays, M.F.

1995-01-01

Composite materials have found a wide range of applications for EDF nuclear plants. Applications include fire pipework, demineralized water, service water, and emergency-supplied service water piping. Some of those pipework is classified nuclear safety, their integrity (resistance to water aging and earthquakes or accidental excess pressure (water hammer)) must be safeguarded. As composite materials generally suffer damage for low energy impacts (under 10 J), the pipes planned for the Civaux power plant have been studied for their resistance to a low speed shock (0 to 50 m/s) and of a 0 to 110 J energy level. For three representative diameters (20, 150, 600 mm), the minimum impact energy that leads to a leak has been determined to be respectively 18, 20 and 48 J. Then the leak rate versus impact energy was plotted; until roughly 90 J, the leak rate remains stable at less than 25 cm 3 /h and raises to higher values (300 cm 3 /h) afterwards. The level of leakage in the range of impact energy tested always stays within the limits set by the Safety Authorities for metallic pipes. These results have been linked to destructive examinations, to clarify the damage mechanisms. Other tests are still ongoing to follow the evolution of the damage and of the leak rate while the pipe is maintained under service pressure during one year

Experimental studies of flooding in nearly horizontal pipes

International Nuclear Information System (INIS)

Choi, Ki Yong

1993-02-01

To investigate the flooding phenomenon in nearly horizontal pipes the experimental studies are performed in the facility with the length of 2160mm, with three different inner diameters of 40mm, 60mm, and 70mm, and with the various inclination angles. Air and water approximately at room temperature and at atmospheric pressure are used as test fluids. The local void factions are measured by the three conductance probes located at the inlet, middle, and exit of water flow, respectively. Two mechanisms governing the transition to flooding are proposed. The effects of pipe end geometry, pipe diameter, and inclination angle are investigated and the comparisons with the slug formation models are conducted. It is found in this study that the transition to flooding is originated from two mechanisms i.e. 'wave instability' and 'high head flooding', and two regions (sub-critical and super-critical) coexist if the air flow increases up to a criticalvalue. It is observed that large roll waves are grown to the critical amplitude in the sub-critical region, does not show any dustive growth phenomenon. When the void fraction in the sub-critical region is used as the parameter for the flooding criterion, Ishii's slug formation model predicts the data without systematid errors. On the other hand, when the voide fraction in the super-critical region is selected as the parameter, Taitel's slug formation model best fitsthe data. Data obtained in the condition of high head flooding are not in good agreement with the results predicted by the slug formation models. Also, the transition criterion to the onset of flooding is very sensitive to the inclination angle, and the effect of pipe end geometry on the onset of flooding is negligible

Modeling of residual stress mitigation in austenitic stainless steel pipe girth weldment

International Nuclear Information System (INIS)

Li, M.; Atteridge, D.G.; Anderson, W.E.; West, S.L.

1994-01-01

This study provides numerical procedures to model 40-cm-diameter, schedule 40, Type 304L stainless steel pipe girth welding and a newly proposed post-weld treatment. The treatment can be used to accomplish the goal of imparting compressive residual stresses at the inner surface of a pipe girth weldment to prevent/retard the intergranular stress corrosion cracking (IGSCC) of the piping system in nuclear reactors. This new post-weld treatment for mitigating residual stresses is cooling stress improvement (CSI). The concept of CSI is to establish and maintain a certain temperature gradient across the pipe wall thickness to change the final stress state. Thus, this process involves sub-zero low temperature cooling of the inner pipe surface of a completed girth weldment, while simultaneously keeping the outer pipe surface at a slightly elevated temperature with the help of a certain heating method. Analyses to obtain quantitative results on pipe girth welding and CSI by using a thermo-elastic-plastic finite element model are described in this paper. Results demonstrate the potential effectiveness of CSI for introducing compressive residual stresses to prevent/retard IGSCC. Because of the symmetric nature of CSI, it shows great potential for industrial application

Application of ultrasonic NDT technique for butt fusion joints of plastic pipes

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Gyung; Lim, Hyung Taik; Choi, Jeong Guen; Lee, Jae Myung [ANSCO, Daejeon (Korea, Republic of)

2016-05-15

The long term-durability and the soundness of the plastic pipe have been sufficiently verified through use of the plastic pipe during the past several decades. Recently, as the pipe material have been constantly developed, the application of the plastic pipe is expanded to various industrial fields, such as an increase of a use pressure, the bigger diameter of the pipe, etc. In a nuclear power plant where a carbon steel pipe and a stainless steel pipe are mainly used as a safety class III buried pipe, safety in an operation is seriously threatened by abrasion, heat deterioration or the like, frequently generated in a metal pipe. Therefore, in order to provide an alternate to this problem there is a rising interest on using high-density polyethylene (HDPE) pipes which are known to provide much enhanced corrosion, abrasion and impact resistant properties. With polyethylene piping, one of the issue that is being looked into is the integrity of butt-fusion joint. At the present time the Referencing Code and Standard for the NDT technology of for butt fusion joint of the plastic pipe have not yet established. An optimum inspection parameters were determined according to the thickness of the HDPE pipe. It was also confirmed that most of the detection results of two techniques have matched with each other. In the PAUT, it is easy to distinguish signals with from the flaws made by the thin plate and the void. Also the resolving power of PAUT on the detection in the depth direction has been demonstrated to be satisfactory.

BOA: Pipe-asbestos insulation removal robot system

International Nuclear Information System (INIS)

Schempf, H.; Bares, J.; Mutschler, E.

1995-01-01

This paper describes the BOA system, a mobile pipe-external crawler used to remotely strip and bag (possibly contaminated) asbestos-containing lagging and insulation materials (ACLIM) from various diameter pipes in (primarily) industrial installations across the DOE weapons complex. The mechanical removal of ACLIM is very cost-effective due to the relatively low productivity and high cost involved in human removal scenarios. BOA, a mechanical system capable of removing most forms of lagging (paper, plaster, aluminum sheet, clamps, screws and chicken-wire), and insulation (paper, tar, asbestos fiber, mag-block) uses a circular cutter and compression paddles to cut and strip the insulation off the pipe through compression, while a HEPA-filter and encapsulant system maintain a certifiable vacuum and moisture content inside the system and on the pipe, respectively. The crawler system has been built and is currently undergoing testing. Key design parameters and performance parameters are developed and used in performance testing. Since the current system is a testbed, we also discuss future enhancements and outline two deployment scenarios (robotic and manual) for the final system to be designed and completed by the end of FY '95. An on-site demonstration is currently planned for Fernald in Ohio and Oak Ridge in Tennessee

Test results of a jet impingement from a 4 inch pipe under BWR LOCA conditions

International Nuclear Information System (INIS)

Isozaki, Toshikuni; Yano, Toshikazu; Miyazaki, Noriyuki; Kato, Rokuro; Kurihara, Ryoichi; Ueda, Shuzo; Miyazono, Shohachiro

1982-09-01

Hypothetical instantaneous pipe rupture is now considered to be one of the design basis accidents during the operation of the light water reactor. If a pipe rupture accidnet occurs, the pipe will start moving with the sudden discharge of internal fluid. So, the various apparatus such as pipe whip restraints and jet deflectors are being installed near the postulated break location to protect the nuclear power plants against the effect of postulated pipe rupture. Pipe whipping test and jet discharge test are now being conducted at the Division of Reactor Safety of the Japan Atomic Energy Research Institute. This report describes the test results of the jet discharge from a 4 inch pipe under BWR LOCA condition. In front of the pipe exit the target disk of 1000 mm in diameter was installed. The distance between the pipe exit and the target was 500 mm. 13 pressure transducers and 13 thermocouples were mounted on the target disk to measure the pressure and temperature increase due to jet impingement on the target. (author)

Steel Fibers Reinforced Concrete Pipes - Experimental Tests and Numerical Simulation

Science.gov (United States)

Doru, Zdrenghea

2017-10-01

The paper presents in the first part a state of the art review of reinforced concrete pipes used in micro tunnelling realised through pipes jacking method and design methods for steel fibres reinforced concrete. In part two experimental tests are presented on inner pipes with diameters of 1410mm and 2200mm, and specimens (100x100x500mm) of reinforced concrete with metal fibres (35 kg / m3). In part two experimental tests are presented on pipes with inner diameters of 1410mm and 2200mm, and specimens (100x100x500mm) of reinforced concrete with steel fibres (35 kg / m3). The results obtained are analysed and are calculated residual flexural tensile strengths which characterise the post-cracking behaviour of steel fibres reinforced concrete. In the third part are presented numerical simulations of the tests of pipes and specimens. The model adopted for the pipes test was a three-dimensional model and loads considered were those obtained in experimental tests at reaching breaking forces. Tensile stresses determined were compared with mean flexural tensile strength. To validate tensile parameters of steel fibres reinforced concrete, experimental tests of the specimens were modelled with MIDAS program to reproduce the flexural breaking behaviour. To simulate post - cracking behaviour was used the method σ — ε based on the relationship stress - strain, according to RILEM TC 162-TDF. For the specimens tested were plotted F — δ diagrams, which have been superimposed for comparison with the similar diagrams of experimental tests. The comparison of experimental results with those obtained from numerical simulation leads to the following conclusions: - the maximum forces obtained by numerical calculation have higher values than the experimental values for the same tensile stresses; - forces corresponding of residual strengths have very similar values between the experimental and numerical calculations; - generally the numerical model estimates a breaking force greater

Pipe rupture hardware minimization in pressurized water reactor system

International Nuclear Information System (INIS)

Mukherjee, S.K.; Szyslowski, J.J.; Chexal, V.; Norris, D.M.; Goldstein, N.A.; Beaudoin, B.; Quinones, D.; Server, W.

1987-01-01

For much of the high energy piping in light water reactor systems, fracture mechanics calculations can be used to assure pipe failure resistance, thus allowing the elimination of excessive rupture restraint hardware both inside and outside containment. These calculations use the concept of leak-before-break (LBB) and include part-through-wall flaw fatigue crack propagation, through-wall flaw detectable leakage, and through-wall flaw stability analyses. Performing these analyses not only reduces initial construction, future maintenance, and radiation exposure costs, but the overall safety and integrity of the plant are improved since much more is known about the piping and its capabilities than would be the case had the analyses not been performed. This paper presents the LBB methodology applied at Beaver Valley Power Station - Unit 2 (BVPS-2); the application for two specific lines, one inside containment (stainless steel) and the other outside containment (ferritic steel), is shown in a generic sense using a simple parametric matrix. The overall results for BVPS-2 indicate that pipe rupture hardware is not necessary for stainless steel lines inside containment greater than or equal to 6-in (152 mm) nominal pipe size that have passed a screening criteria designed to eliminate potential problem systems (such as the feedwater system). Similarly, some ferritic steel lines as small as 3-in (76 mm) diameter (outside containment) can qualify for pipe rupture hardware elimination

Inter granular stress corrosion cracking of Ignalina NPP austenitic piping of outside diameter 325 mm

International Nuclear Information System (INIS)

Nedzinskas, L.; Klimasauskas, A.

2003-01-01

The Inter Granular Stress Corrosion Cracking (IGSCC) of Ignalina NPP main circulation circuit piping, produced from austenitic stainless steel is presented covering current performances and further 'Ageing Management' related actions and plans as well as experience (lessons learned) on solving IGSCC phenomenon, which is currently under investigations and no yet comprehensive answer how to avoid it. (author)

Risk based service life prediction of underground cast iron pipes subjected to corrosion

International Nuclear Information System (INIS)

Li, C.Q.; Mahmoodian, M.

2013-01-01

Aging and deterioration of underground cast iron pipes is inevitable after their long time in service, with corrosion being the most predominant mechanism for pipe failures. Although considerable research has been undertaken in the past few decades, more is on the effects of corrosion on structural capacity of pipes than that on the prediction of their service life. This paper presents a methodology to quantitatively assess the risk of pipe collapse and predict its remaining service life using a time-dependent reliability theory. The concept of stress intensity in fracture mechanics is employed to establish the failure criterion of pipe collapse. An empirical model is derived for maximum pit growth of corrosion from the available data based on mathematical regressions. An example is provided to illustrate the application of the proposed method. It is found in the paper that the risk of pipe collapse increases with an increase in the diameter of the pipe for both external and internal corrosion. It is also found that the tougher the pipe is, the smaller the risk of its collapse. The paper concludes that a time-dependent reliability method is a very useful tool to predict the risk of pipe collapse and its remaining service life. The proposed method can help the water industry develop rehabilitation or replacement strategy for existing pipe networks with a view for better management of the pipe asset

Efficient methods of piping cleaning

Directory of Open Access Journals (Sweden)

Orlov Vladimir Aleksandrovich

2014-01-01

Full Text Available The article contains the analysis of the efficient methods of piping cleaning of water supply and sanitation systems. Special attention is paid to the ice cleaning method, in course of which biological foil and various mineral and organic deposits are removed due to the ice crust buildup on the inner surface of water supply and drainage pipes. These impurities are responsible for the deterioration of the organoleptic properties of the transported drinking water or narrowing cross-section of drainage pipes. The co-authors emphasize that the use of ice compared to other methods of pipe cleaning has a number of advantages due to the relative simplicity and cheapness of the process, economical efficiency and lack of environmental risk. The equipment for performing ice cleaning is presented, its technological options, terms of cleansing operations, as well as the volumes of disposed pollution per unit length of the water supply and drainage pipelines. It is noted that ice cleaning requires careful planning in the process of cooking ice and in the process of its supply in the pipe. There are specific requirements to its quality. In particular, when you clean drinking water system the ice applied should be hygienically clean and meet sanitary requirements.In pilot projects, in particular, quantitative and qualitative analysis of sediments adsorbed by ice is conducted, as well as temperature and the duration of the process. The degree of pollution of the pipeline was estimated by the volume of the remote sediment on 1 km of pipeline. Cleaning pipelines using ice can be considered one of the methods of trenchless technologies, being a significant alternative to traditional methods of cleaning the pipes. The method can be applied in urban pipeline systems of drinking water supply for the diameters of 100—600 mm, and also to diversion collectors. In the world today 450 km of pipelines are subject to ice cleaning method.Ice cleaning method is simple

Numerical simulation of bubbles motion in lifting pipe of bubble pump for lithium bromide absorption chillers

International Nuclear Information System (INIS)

Gao, Hongtao; Liu, Bingbing; Yan, Yuying

2017-01-01

A bubble pump is proposed to replace the traditional mechanical solution pump in lithium bromide absorption chillers, for its advantageous feature that can be driven by industrial waste heat or solar energy or other low-grade energy. In two-stage bubble pump driven lithium bromide absorption refrigeration system, flow patterns in lifting pipe have significant effects on the performance of bubble pump. In this paper, the single bubble motion and the double bubbles coalescence in vertical ascending pipe are simulated by an improved free energy model of lattice Boltzmann method, in which the two-phase liquid to gas density ratio is 2778. The details of bubbles coalescence process are studied. Density and velocity of bubbles have been obtained. The computational results show that the initial radius of each bubble has a great influence on the coalescence time. The larger the initial bubble radius, the shorter the coalescence time. The pipe diameter has a little effect on the two bubbles coalescence time while it has a significant effect on the bubble velocity. As the pipe diameter increases, the bubble velocity increases. The obtained results are helpful for studying the transition mechanisms of two-phase flow patterns and useful for improving the bubble pump performance by controlling the flow patterns in lifting pipe.

Off-take and slug transition at T-junction of vertical-up branch in the horizontal pipe

International Nuclear Information System (INIS)

Moon, Young Min; No, Hee Cheon

2003-01-01

The off-take and the slug transition on air-water interface are experimentally investigated at the T-junction of the horizontal pipe with a vertical upward branch to simulate the loss-of-residual-heat-removal during a mid-loop operation in the Korea standard nuclear power plant. Scaling analysis is performed to scale down the experimental facility to the reference nuclear power plant. Two different diameters of branch pipes are used to verify the scaling laws and their scale effects. Air is used as working gaseous fluid and no water flow exists. Off-take behavior on horizontal stratified and slug flows is visually observed in the horizontal pipe. The experimental data are divided into three categories; onset of liquid entrainment at T-junctions, onset of slug transition in the horizontal pipe, and discharge quality in the branch pipe. It is found out that the scale effect of the branch diameter on the onset of liquid entrainment is small and the existing correlations for it are applicable. Also, the onset of slug transition shows a discrepancy with Taitel-Dukler's correlation and has a strong influence on the discharge quality. New correlations for discharge quality are developed considering the critical dependency of the onset of slugging. (author)

Development of a Skewed Pipe Shear Connector for Precast Concrete Structures.

Science.gov (United States)

Kim, Sang-Hyo; Choi, Jae-Gu; Park, Sejun; Lee, Hyunmin; Heo, And Won-Ho

2017-05-13

Joint connection methods, such as shear key and loop bar, improve the structural performance of precast concrete structures; consequently, there is usually decreased workability or constructional efficiency. This paper proposes a high-efficiency skewed pipe shear connector. To resist shear and pull-out forces, the proposed connectors are placed diagonally between precast concrete segments and a cast-in-place concrete joint part on a girder. Design variables (such as the pipe diameter, length, and insertion angle) have been examined to investigate the connection performance of the proposed connector. The results of our testing indicate that the skewed pipe shear connectors have 50% higher ductility and a 15% higher ratio of maximum load to yield strength as compared to the corresponding parameters of the loop bar. Finite element analysis was used for validation. The resulting validation indicates that, compared to the loop bar, the skewed pipe shear connector has a higher ultimate shear and pull-out resistance. These results indicate that the skewed pipe shear connector demonstrates more idealized behavior than the loop bar in precast concrete structures.

Particle clustering within a two-phase turbulent pipe jet

Science.gov (United States)

Lau, Timothy; Nathan, Graham

2016-11-01

A comprehensive study of the influence of Stokes number on the instantaneous distributions of particles within a well-characterised, two-phase, turbulent pipe jet in a weak co-flow was performed. The experiments utilised particles with a narrow size distribution, resulting in a truly mono-disperse particle-laden jet. The jet Reynolds number, based on the pipe diameter, was in the range 10000 developed technique. The results show that particle clustering is significantly influenced by the exit Stokes number. Particle clustering was found to be significant for 0 . 3 financial contributions by the Australian Research Council (Grant No. DP120102961) and the Australian Renewable Energy Agency (Grant No. USO034).

Long-Range Piping Inspection by Ultrasonic Guided Waves

International Nuclear Information System (INIS)

Joo, Young Sang; Lim, Sa Hoe; Eom, Heung Seop; Kim, Jae Hee

2005-01-01

The ultrasonic guided waves are very promising for the long-range inspection of large structures because they can propagate a long distance along the structures such as plates, shells and pipes. The guided wave inspection could be utilized for an on-line monitoring technique when the transmitting and receiving transducers are positioned at a remote point on the structure. The received signal has the information about the integrity of the monitoring area between the transmitting and receiving transducers. On-line monitoring of a pipe line using an ultrasonic guided wave can detect flaws such as corrosion, erosion and fatigue cracking at an early stage and collect useful information on the flaws. However the guided wave inspection is complicated by the dispersive characteristics for guided waves. The phase and group velocities are a function of the frequency-thickness product. Therefore, the different frequency components of the guided waves will travel at different speeds and the shape of the received signal will changed as it propagates along the pipe. In this study, we analyze the propagation characteristics of guided wave modes in a small diameter pipe of nuclear power plant and select the suitable mode for a long-range inspection. And experiments will be carried out for the practical application of a long-range inspection in a 26m long pipe by using a high-power ultrasonic inspection system

Useful effectiveness of plastic pipes for gas pipelines operating at low pressure

Energy Technology Data Exchange (ETDEWEB)

Zayutsev, K I

1976-06-01

Because a significant portion of the feeder lines in the Soviet union operate at relatively low pressures up to 75 to 150 psi, it is economically feasible to replace the conventional pipeline material (steel) with plastic. Cost savings result from lower material costs and ease of laying plastic pipe. Because of stiffness and corrosion requirements, the steel pipe used for these low-pressure pipelines is much thicker than needed to withstand the pressure used. Data are tabulated on the comparative costs and manpower requirements for the construction of 1 km of steel, polyvinyl chloride, and polyethylene gas pipelines ranging in diameter from 3 to 14 in. Generally, the plastic pipelines required 15 to 30% less man-days and were 20 to 35% lower in cost to build. The plastic pipelines can operate at 150 to 175 psi pressure and at temperatures up to 100 to 140/sup 0/F. In research conducted at VNIIST (All-Union Research Institute for the Construction of Trunk Pipelines) on plastic pipelines, a 2.5-mile test section has been operating successfully for 2 years, and new techniques and equipment for joining plastic pipe up to 25-in. diameter are being developed.

Automated Hydroforming of Seamless Superconducting RF Cavity

International Nuclear Information System (INIS)

Nagata, Tomohiko; Shinozawa, Seiichi; Abe, Noriyuki; Nagakubo, Junki; Murakami, Hirohiko; Tajima, Tsuyoshi; Inoue, Hitoshi; Yamanaka, Masashi; Ueno, Kenji

2012-01-01

We are studying the possibility of automated hydroforming process for seamless superconducting RF cavities. Preliminary hydroforming tests of three-cell cavities from seamless tubes made of C1020 copper have been performed. The key point of an automated forming is to monitor and strictly control some parameters such as operation time, internal pressure and material displacements. Especially, it is necessary for our studies to be able to control axial and radial deformation independently. We plan to perform the forming in two stages to increase the reliability of successful forming. In the first stage hydroforming by using intermediate constraint dies, three-cell cavities were successfully formed in less than 1 minute. In parallel, we did elongation tests on cavity-quality niobium and confirmed that it is possible to achieve an elongation of >64% in 2 stages that is required for our forming of 1.3 GHz cavities.

A Robotic System for Inspection and Repair of Small Diameter Pipelines

Directory of Open Access Journals (Sweden)

S. A. Vorotnikov

2015-01-01

Full Text Available This paper deals with the construction and control system of miniature robotic system that is designed to move and make inspection inside small diameter pipelines. It gives an overview of ways to move a microsize robotic system inside the small diameter pipe. The proposed design consists of information module and three traction modules, including modules for fixing, linear moving and angular positioning. This paper describes the design and operation of a robotic system and its different modules. Also are shown the structure of the robot control system, the basic calculations of construct and some simulation results of the individual modules of the robot.

Modeling of surface roughness effects on Stokes flow in circular pipes

Science.gov (United States)

Song, Siyuan; Yang, Xiaohu; Xin, Fengxian; Lu, Tian Jian

2018-02-01

Fluid flow and pressure drop across a channel are significantly influenced by surface roughness on a channel wall. The present study investigates the effects of periodically structured surface roughness upon flow field and pressure drop in a circular pipe at low Reynolds numbers. The periodic roughness considered exhibits sinusoidal, triangular, and rectangular morphologies, with the relative roughness (i.e., ratio of the amplitude of surface roughness to hydraulic diameter of the pipe) no more than 0.2. Based upon a revised perturbation theory, a theoretical model is developed to quantify the effect of roughness on fully developed Stokes flow in the pipe. The ratio of static flow resistivity and the ratio of the Darcy friction factor between rough and smooth pipes are expressed in four-order approximate formulations, which are validated against numerical simulation results. The relative roughness and the wave number are identified as the two key parameters affecting the static flow resistivity and the Darcy friction factor.

Machining of the nuclear tube sheet with small hole diameter

International Nuclear Information System (INIS)

Lin Lifeng

2010-01-01

Regarding the tube sheet for the heat exchanger of Qinshan Phase II extension project, its material is 00Cr19Ni10 forgings, the tube sheet thickness is 125 mm, requiring 178-φ10.35 0 +0.05 hole, the tube array shall take the shape of equilateral triangle, the center distance is 15 mm, and the tube hole roughness is Ra 3.2. The guide sleeve shall be adopted for positioning prior to machining of the high precision small hole of the thick tube sheet, and the gun drill and BTA drill shall be adopted for testing, finally BTA drilling with internal chip removal shall be adopted, this method shall overcome the disadvantage factor of BTA drilling and shall be the new approach for drilling. The diameter of BTA drill is φ10.34 mm. The machined hole diameter shall be φ10.375-φ10.355 mm. The ellipticity of the tube hole shall be less than 0.01 mm, the pipe bridge dimension shall be 4.6 mm, conforming to the requirement of the drawing. The paper presents the precautions during machining so as to provide the reference for the similar pipe hole machining in the future. (author)

Pipe-to-pipe impact program

International Nuclear Information System (INIS)

Alzheimer, J.M.; Bampton, M.C.C.; Friley, J.R.; Simonen, F.A.

1984-06-01

This report documents the tests and analyses performed as part of the Pipe-to-Pipe Impact (PTPI) Program at the Pacific Northwest Laboratory. This work was performed to assist the NRC in making licensing decisions regarding pipe-to-pipe impact events following postulated breaks in high energy fluid system piping. The report scope encompasses work conducted from the program's start through the completion of the initial hot oil tests. The test equipment, procedures, and results are described, as are analytic studies of failure potential and data correlation. Because the PTPI Program is only partially completed, the total significance of the current test results cannot yet be accurately assessed. Therefore, although trends in the data are discussed, final conclusions and recommendations will be possible only after the completion of the program, which is scheduled to end in FY 1984

Heat exchanger nozzle stresses due to pipe vibration

International Nuclear Information System (INIS)

Wolgemuth, G.A.

1983-01-01

A large diameter pipe in a heavy water production plant was excited into a low frequency vibration due to void collapse of the pipe contents at a sharp vertical drop in the pipe run. Fears that this vibration would fatigue the inlet nozzle to the heat exchanger prompted the introduction of a flow of cold water into the pipe to prevent the two-phase flow from developing but at the cost of reduced heat exchanger efficiency. An investigation was carried out to determine the stress levels in the nozzle with the quenching flow off and suggest means of reducing them if excessive. A finite element dynamic simulation of the pipe run was performed to determine the likely mode shapes. This information was used to optimize the placement of velocity probes on the pipe. Field measurements of vibration were taken for several operating conditions. This data was analyzed and the results used to refine the support stiffness used in the finite element simulation. The finite element model was then used to predict the nozzle forces and moments. In turn this data was used to determine the local stresses in the nozzle. The ASME Section III code was used to determine the allowable fully reversing stresses for the unit in question. It was found that the endurance limit of 83 MPa was exceeded in the analysis only when using the most conservative estimates for each uncertainty. It was recommended that if the safety factor was not deemed high enough, the nozzle should be built up with a reinforcing pad no thicker than 12 mm

A seamless ubiquitous emergency medical service for crisis situations.

Science.gov (United States)

Lin, Bor-Shing

2016-04-01

In crisis situations, a seamless ubiquitous communication is necessary to provide emergency medical service to save people's lives. An excellent prehospital emergency medicine provides immediate medical care to increase the survival rate of patients. On their way to the hospital, ambulance personnel must transmit real-time and uninterrupted patient information to the hospital to apprise the physician of the situation and provide options to the ambulance personnel. In emergency and crisis situations, many communication channels can be unserviceable because of damage to equipment or loss of power. Thus, data transmission over wireless communication to achieve uninterrupted network services is a major obstacle. This study proposes a mobile middleware for cognitive radio (CR) for improving the wireless communication link. CRs can sense their operating environment and optimize the spectrum usage so that the mobile middleware can integrate the existing wireless communication systems with a seamless communication service in heterogeneous network environments. Eventually, the proposed seamless mobile communication middleware was ported into an embedded system, which is compatible with the actual network environment without the need for changing the original system architecture. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Localised surface plasmon-like resonance generated by microwave electromagnetic waves in pipe defects

Science.gov (United States)

Alobaidi, Wissam M.; Nima, Zeid A.; Sandgren, Eric

2018-01-01

Localised surface plasmon (LSP)-like resonance phenomena were simulated in COMSOL Multiphysics™, and the electric field enhancement was evaluated in eight pipe defects using the microwave band from 1.80 to 3.00 GHz and analysed by finite element analysis (FEA). The simulation was carried out, in each defect case, on a pipe that has 762 mm length and 152.4 mm inner diameter, and 12.7 mm pipe wall thickness. Defects were positioned in the middle of the pipe and were named as follows; SD: Square Defect, FCD: fillet corner defect, FD: fillet defect, HCD: half circle defect, TCD: triangle corner defect, TD: triangle defect, ZD: zigzag defect, GD: gear defect. The LSP electric field, and scattering parametric (S21, and S11) waves were evaluated in all cases and found to be strongly dependent on the size and the shape of the defect rather than the pipe and or the medium materials.

Hydroforming SRF Three-cell Cavity from Seamless Niobium Tube

Energy Technology Data Exchange (ETDEWEB)

Yamanaka, Masashi [KEK, Tsukuba; Dohmae, Takeshi [KEK, Tsukuba; Hocker, Andy [Fermilab; Inoue, Hitoshi [KEK, Tsukuba; Park, Gunn-Tae [KEK, Tsukuba; Tajima, Tsuyoshi [Los Alamos; Umemori, Kensei [KEK, Tsukuba

2016-06-01

We are developing the manufacturing method for superconducting radio frequency (SRF) cavities by using a hydroforming instead of using conventional electron beam welding. We expect higher reliability and reduced cost with hydroforming. For successful hydroforming, high-purity seamless niobium tubes with good formability as well as advancing the hydroforming technique are necessary. Using a seamless niobium tube from ATI Wah Chang, we were able to successfully hydroform a 1.3 GHz three-cell TESLA-like cavity and obtained an Eacc of 32 MV/m. A barrel polishing process was omitted after the hydroforming. The vertical test was carried out with very rough inside surface. We got amazing and interesting result.

Velocity and turbulence measurements of oil-water flow in horizontal and slightly inclined pipes using PIV

OpenAIRE

Kumara, W.A.S.; Halvorsen, Britt; Melaaen, Morten Christian

2009-01-01

Oil-water flows in horizontal and slightly inclined pipes are investigated using Particle Image Velocimetry (PIV). PIV offers a powerful non-invasive tool to study such flow fields. The experiments are conducted in a 15 m long, 56 mm diameter, inclinable steel pipe using Exxsol D60 oil (viscosity 1.64 mPa s, density 790 kg/m3) and water (viscosity 1.0 mPa s, density 996 kg/m3) as test fluids. The test pipe inclination is changed in the range from 5° upward to 5° downward. The experiments are ...

A study for a guide chart of lower and upper boundary regions to avoid the condensation-induced water hammer in a long horizontal pipe

International Nuclear Information System (INIS)

Lee, Byung Jin

1995-02-01

Effects of the key system parameters such as the pipe length, the pipe diameter, the feedwater temperature and the system pressure on the critical flow rates of both the upper and the lower boundaries have been examined for long horizontal pipes. The upper and lower critical flow rates are sensitive to the pipe diameter, the pipe length and the system pressure, but not to the feedwater temperature over the practical operating ranges. Guide charts of the CIWH region boundary have been developed to be used in the system design and operation to predict the operating conditions vulnerable to the CIWH. The charts illustrate a series of the operating ranges bounded by the lower and the upper limiting curves where the water hammer is very likely to occur. A design and operational procedure has also been provided to help the designer and the operator to avoid the CIWH

TSTA Piping and Flame Arrestor Operating Experience Data

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, Lee C.; Willms, R. Scott

2014-10-01

The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium handling technology and experiment research at the Los Alamos National Laboratory. The facility operated from 1984 to 2001, running a prototype fusion fuel processing loop with ~100 grams of tritium as well as small experiments. There have been several operating experience reports written on this facility’s operation and maintenance experience. This paper describes analysis of two additional components from TSTA, small diameter gas piping that handled small amounts of tritium in a nitrogen carrier gas, and the flame arrestor used in this piping system. The operating experiences and the component failure rates for these components are discussed in this paper. Comparison data from other applications are also presented.

Development of a screening procedure for vibrational fatigue in small bore piping

International Nuclear Information System (INIS)

Smith, J.K.; Riccardella, P.C.; Gosselin, S.R.

1995-01-01

Approximately 80% of the documented fatigue failures in nuclear power plants are caused by high cycle vibrational fatigue. These failures typically occur in socket welded pipe fittings in small bore piping (2 in. nominal diameter and smaller). These failures have been unexpected, and have caused costly, unscheduled outages in some cases. In order to reduce the number of vibrational fatigue failures in operating nuclear power plants, a vibrational fatigue screening procedure has been developed under Electric Power Research Institute (EPRI) sponsorship. The purpose of this paper is to describe this procedure, and to discuss topics related to vibrational fatigue failures. These topics include sources of vibration in nuclear power plants, the effect of socket welds on vibrational fatigue failures, vibrational fatigue screening criteria for small bore piping systems, and good design practices for reducing the number of vibrational fatigue failures in small bore piping

Alpha contamination assessment for D ampersand D activities: Monitoring pipe interiors

International Nuclear Information System (INIS)

Rawool-Sullivan, M.W.; Conaway, J.G.; MacArthur, D.W.; Vaccarella, J.

1996-02-01

We have developed a prototype instrument capable of assessing alpha-emitting contamination on interior surfaces of ducts, pipes, tanks, and other enclosed volumes without inserting a probe. Air is drawn through the potentially contaminated volume and then through a detection grid, where ions created in the air by alpha particles are collected and the resulting charge measured with a sensitive electrometer. A filter at the intake end of the contaminated volume excludes externally created ions, so only ions generated inside the volume are detected. We have studied the response of this prototype in initial experiments using calibrated alpha sources with various pipe diameters and configurations, air flows, and source locations in the pipes. The results of these experiments indicate that this method can be an effective approach to assessing internal contamination

49 CFR 179.500 - Specification DOT-107A * * * * seamless steel tank car tanks.

Science.gov (United States)

2010-10-01

... car tanks. 179.500 Section 179.500 Transportation Other Regulations Relating to Transportation... REGULATIONS SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.500 Specification DOT-107A * * * * seamless steel tank car tanks. ...

A leak-before-break strategy for CANDU primary piping systems

International Nuclear Information System (INIS)

Aggarwal, M.L.; Kozluk, M.J.; Lin, T.C.; Manning, B.W.; Vijay, D.K.

1986-01-01

Recent advances in elastic-plastic fracture mechanics have made it possible to assess the stability of cracks in ductile piping systems. These technological developments have been used by Ontario Hydro as the nucleus of an approach for demonstrating that CANDU primary heat transport piping systems will not break catastrophically; at worst they would leak at a detectable rate. This leak-before-break approach has been taken on the Darlington nuclear generating station as a design stage alternative to the provision of pipe whip restraints on large diameter, primary heat transport system piping. Positive conclusions reached via this approach are considered sufficient to exclude the requirement to provide protective devices, such as pipe whip restraints. In arriving at the proposed leak-before-break approach a review of current and proposed leak-before-break licensing positions of other jurisdictions (particularly those in the United States and the Federal Republic of Germany) was carried out. The approach presented makes use of recent American developments in the area of elastic-plastic fracture mechanics. It also gives consideration to aspects which are unique to the pressurized heavy water (CANDU) reactors used by Ontario Hydro. The proposed leak-before-break approach is described and its use is illustrated by applying it to the Darlington generating station primary heat transport system pump suction piping. (author)

Seamless service: maintaining momentum.

Science.gov (United States)

Grinstead, N; Timoney, R

1994-01-01

Describes the process used by the Mater Infirmorum Hospital in Belfast in 1992-1994 to achieve high quality care (Seamless Service), motivate staff to deliver and measure performance. Aims of the project include focusing the organization on the customer, improving teamwork and motivation at all levels. After comprehensive data collection from GPs, patients and staff management forums developed a full TQM strategy to gain support and maintain momentum including innovative staff events (every staff member was given the opportunity to attend) where multilevel, multidisciplinary workshops enabled staff to design customer care standards, develop teams and lead customer-driven change.

Degradation of homogeneous polymer solutions in high shear turbulent pipe flow

Science.gov (United States)

Elbing, B. R.; Winkel, E. S.; Solomon, M. J.; Ceccio, S. L.

2009-12-01

This study quantifies degradation of polyethylene oxide (PEO) and polyacrylamide (PAM) polymer solutions in large diameter (2.72 cm) turbulent pipe flow at Reynolds numbers to 3 × 105 and shear rates greater than 105 1/s. The present results support a universal scaling law for polymer chain scission reported by Vanapalli et al. (2006) that predicts the maximum chain drag force to be proportional to Re 3/2, validating this scaling law at higher Reynolds numbers than prior studies. Use of this scaling gives estimated backbone bond strengths from PEO and PAM of 3.2 and 3.8 nN, respectively. Additionally, with the use of synthetic seawater as a solvent the onset of drag reduction occurred at higher shear rates relative to the pure water solvent solutions, but had little influence on the extent of degradation at higher shear rates. These results are significant for large diameter pipe flow applications that use polymers to reduce drag.

Analysis of the failure performance of internally pressurized piping with surface flaws

International Nuclear Information System (INIS)

Iorio, A.F; Crespi, J.C.

1987-01-01

Due to frequent failures an Atucha I PHWR moderator circuit branch piping, made of stainless steel type AISI 347 (DIN 1.4550), studies have been made, involving the application of several fracture mechanics criteria, in order to determine the conditions of leak-before-break (L.BB) and the critical crack length of the piping. These studies lead to the conclusions that, for a straight pipe of outer diameter of 219 mm and 16 mm wall thickness, with a circumferential flaw and the principal stress being in the bending, the L.BB criteria are satisfied, being the critical crack length of the order of 400 mm. A better mechanical finishing and heat treatment was suggested in order to improve the resistance to crack initiation. (Author)

Conformally encapsulated multi-electrode arrays with seamless insulation

Energy Technology Data Exchange (ETDEWEB)

Tabada, Phillipe J.; Shah, Kedar G.; Tolosa, Vanessa; Pannu, Satinderall S.; Tooker, Angela; Delima, Terri; Sheth, Heeral; Felix, Sarah

2016-11-22

Thin-film multi-electrode arrays (MEA) having one or more electrically conductive beams conformally encapsulated in a seamless block of electrically insulating material, and methods of fabricating such MEAs using reproducible, microfabrication processes. One or more electrically conductive traces are formed on scaffold material that is subsequently removed to suspend the traces over a substrate by support portions of the trace beam in contact with the substrate. By encapsulating the suspended traces, either individually or together, with a single continuous layer of an electrically insulating material, a seamless block of electrically insulating material is formed that conforms to the shape of the trace beam structure, including any trace backings which provide suspension support. Electrical contacts, electrodes, or leads of the traces are exposed from the encapsulated trace beam structure by removing the substrate.

Investigations on penetration control for automated pipe welding system

International Nuclear Information System (INIS)

Fujiki, Daisuke; Sato, Akihiro; Funamoto, Takao; Matsumoto, Toshimi; Kobayashi, Masahiro

1995-01-01

We have been investigating process conditions forming sound root bead by orbital welding technique for nuclear power stations. Specimens used were stainless steel (SUS304) pipes (318.5 mm outside diameter and 15.4 mm thickness), and pulsed gas tungsten-arc (GTA) welder was adopted. We have found process conditions to form sound root bead by changing both heat input conditions and joint designs. It is found that reducing volume of molten metal is necessary to form sound root bead. And it is also found that changing joint designs is effective to reduce volume of molten metal. By selecting proper joint designs, we could form sound root bead in constant heat input conditions in every position of pipe. (author)

A study on the characteristics of upward air-water two-phase flow in a large pipe

International Nuclear Information System (INIS)

Shen, Xiuzhong; Mishima, Kaichiro; Nakamura, Hideo

2003-01-01

Adiabatic upward air-water two-phase flow in a vertical large pipe (inner diameter, D: 0.2 m, ratio of pipe length to diameter, L/D: 60.5.) was experimentally investigated under various inlet conditions. Flow regime was observed and void fraction, bubble frequency, Sauter mean diameter, interfacial area concentration (IAC) and interfacial direction were measured with optical four-sensor probe. Characteristics of various flow regimes were analyzed carefully. Both the void fraction and the IAC demonstrated radial wall-peak and core-peak distributions in the undisturbed bubbly flow and the other flow regimes, respectively. The existence of bubbly secondary flow accounts for the core-peak distribution in the agitated bubbly, churn bubbly, churn slug and churn froth flow. The bubble frequency showed a wall-peak radial distribution only when the bubbles were small in diameter and the flow was in the undisturbed bubbly flow. The Sauter mean diameter of bubbles did not change much in the main flow of undisturbed bubbly, agitated bubbly and churn bubbly flow regimes and showed a core peak radial distribution in the churn slug flow. In the latter flow regime, the secondary flow disintegrated the bubbles, resulting in the decrease of the Sauter mean diameter. The measurements of the interfacial direction showed that the bubbly main flow and secondary flow can be displayed by the main flow peak and the secondary flow peak, respectively, in the PDF of the interfacial directional angle between the interfacial direction and the z-axis, η zi . The local average η zi at the bubble front hemispheres reflects the local bubble movement and is in direct connection with the flow regimes. Based on the analysis, the authors classified the flow regimes in the vertical large pipe quantitatively by the local average η zi . Bubbles in the liquid phase moved in a zigzag line with no inclination toward any direction in the plane vertical to z-axis in the pipe core. The axial differential

Qualification of Manual Phased Array Ultrasonic Techniques for Pipe Weld Inspection in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Poirier, J.; Hayes, P.; Vicat, F. [GE Inspection Technologies (United States)

2011-07-01

Phasor XS can be used for piping weld inspection in any facilities that use EPRI procedures (example: nuclear power plant in Usa, Japan, ...). Whole pipe range is inspected with 5 probes and 6 wedges: 4 1-dimensional probe for sound wave scanning (different frequency, different apertures); 1 dual matrix probe for LW scanning; there are 3 types of wedges optimized for weld inspection. Weld is scanned in 'Raster Scan', maximum range from 35 up to 80 degrees. Probe selection is defined in the procedure according to pipe diameter, pipe thickness and type of access (single or dual side). We have to note that datasets for dual matrix probe are provided with the procedure because this kind of probe cannot be programmed inside Phasor XS

On the impact bending test technique for high-strength pipe steels

Science.gov (United States)

Arsenkin, A. M.; Odesskii, P. D.; Shabalov, I. P.; Likhachev, M. V.

2015-10-01

It is shown that the impact toughness (KCV-40 = 250 J/cm2) accepted for pipe steels of strength class K65 (σy ≥ 550 MPa) intended for large-diameter gas line pipes is ineffective to classify steels in fracture strength. The results obtained upon testing of specimens with a fatigue crack and additional sharp lateral grooves seem to be more effective. In energy consumption, a macrorelief with splits is found to be intermediate between ductile fracture and crystalline brittle fracture. A split formation mechanism is considered and a scheme is proposed for split formation.

Electrolytic etching of fine stainless-steel pipes patterned by laser-scan lithography

Science.gov (United States)

Takahashi, Hiroshi; Sagara, Tomoya; Horiuchi, Toshiyuki

2017-07-01

Recently, it is required to develop a method for fabricating cylindrical micro-components in the field of measurement and medical engineering. Here, electrolytic etching of fine stainless-steel pipes patterned by laser-scan lithography was researched. The pipe diameter was 100 μm. At first, a pipe coated with 3-7 μm thick positive resist (tok, PMER P LA-900) was exposed to a violet laser beam with a wavelength of 408 nm (Neoark,TC20-4030-45). The laser beam was reshaped in a circle by placing a pinhole, and irradiated on the pipe by reducing the size in 1/20 using a reduction projection optics. Linearly arrayed 22 slit patterns with a width of 25 μm and a length of 175 μm were delineated in every 90-degree circumferential direction. That is, 88 slits in total were delineated at an exposure speed of 110 μm/s. In the axial direction, patterns were delineated at intervals of 90 μm. Following the pattern delineation, the pipe masked by the resist patterns was electrolytically etched. The pipe was used as an anode and an aluminum cylinder was set as a cathode around the pipe. As the electrolyte, aqueous solution of NaCl and NH4Cl was used. After etching the pipe, the resist was removed by ultrasonic cleaning in acetone. Although feasibility for fabricating multi-slit pipes was demonstrated, sizes of the etched slits were enlarged being caused by the undercut, and the shapes were partially deformed, and all the pipes were snapped at the chuck side.

Numerical Study of Piping Limits for Installation of Large Diameter Buckets in Layered Sand

DEFF Research Database (Denmark)

Ibsen, Lars Bo; Thilsted, C.L.

2010-01-01

The bucket foundations, often referred as ‘suction caissons’, are large cylindrical structures, typically made in steel. The bucket foundations have the potential to be the cost-effective option for offshore wind turbines, if suction assisted penetration is employed. Suction installation may cause...... gradients developing in response to applied suction and the results are presented as simple closed form solutions useful for evaluation of suction thresholds against piping. These close form solutions are compared with large scale model test, performed in a natural seabed at a test site in Frederikshavn...

Study on production mechanism of welding residual stress at the juncture of a pipe penetrating a thick plate

International Nuclear Information System (INIS)

Mochizuki, Masahito; Enomoto, Kunio; Okamoto, Noriaki; Saitoh, Hideyo; Hayashi, Eisaku.

1994-01-01

This paper studies welding residual stresses at the intersection of a small diameter pipe penetrating a thick plate. The pipe is welded to the plate, and Tungsten Innert Gas (TIG) cladding is melted on the inner surface of the pipe to protect it from stress corrosion cracking due to long operation in nuclear power plants. Stresses are calculated by heat conduction analysis and thermal elasto-plastic analysis, and also measured by strain gauges. Welding residual stresses are shown to have no corrosive influence on the inner pipe surface, and the stresses are compressed enough to protect the pipe against stress corrosion cracking on the outer surface. It was also studied to make clear the production mechanism of the residual stresses which were generated by welding processes at the pipe. (author)

Optimum Design of FGX-CNT-Reinforced Reddy Pipes Conveying Fluid Subjected to Moving Load

Directory of Open Access Journals (Sweden)

Farid Vakili Tahami

2016-12-01

Full Text Available The harmony search algorithm is applied to the optimum designs of functionally graded (FG-carbon nanotubes (CNTs-reinforced pipes conveying fluid which are subjected to a moving load. The structure is modeled by the Reddy cylindrical shell theory, and the motion equations are derived by Hamilton's principle. The dynamic displacement of the system is derived based on the differential quadrature method (DQM. Moreover, the length, thickness, diameter, velocity, and acceleration of the load, the temperature and velocity of the fluid, and the volume fraction of CNT are considered for the design variables. The results illustrate that the optimum diameter of the pipe is decreased by increasing the volume percentage of CNTs. In addition, by increasing the moving load velocity and acceleration, the FS is decreased.

Scalability Optimization of Seamless Positioning Service

Directory of Open Access Journals (Sweden)

Juraj Machaj

2016-01-01

Full Text Available Recently positioning services are getting more attention not only within research community but also from service providers. From the service providers point of view positioning service that will be able to work seamlessly in all environments, for example, indoor, dense urban, and rural, has a huge potential to open new markets. However, such system does not only need to provide accurate position estimates but have to be scalable and resistant to fake positioning requests. In the previous works we have proposed a modular system, which is able to provide seamless positioning in various environments. The system automatically selects optimal positioning module based on available radio signals. The system currently consists of three positioning modules—GPS, GSM based positioning, and Wi-Fi based positioning. In this paper we will propose algorithm which will reduce time needed for position estimation and thus allow higher scalability of the modular system and thus allow providing positioning services to higher amount of users. Such improvement is extremely important, for real world application where large number of users will require position estimates, since positioning error is affected by response time of the positioning server.

TSTA piping and flame arrestor operating experience data

Energy Technology Data Exchange (ETDEWEB)

Cadwallader, Lee C., E-mail: Lee.Cadwallader@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States); Willms, R. Scott [ITER International Organization, Cadarache (France)

2015-10-15

Highlights: • Experiences from the Tritium Systems Test Assembly were examined. • Failure rates of copper piping and a flame arrestor were calculated. • The calculated failure rates compared well to similar data from the literature. • Tritium component failure rate data support fusion safety assessment. - Abstract: The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium handling technology and experiment research at the Los Alamos National Laboratory. The facility was operated with tritium for its research and development program from 1984 to 2001, running a prototype fusion fuel processing loop with ∼100 g of tritium as well as small experiments. There have been several operating experience reports written on this facility's operation and maintenance experience. This paper describes reliability analysis of two additional components from TSTA, small diameter copper gas piping that handled tritium in a nitrogen carrier gas, and the flame arrestor used in this piping system. The component failure rates for these components are discussed in this paper. Comparison data from other applications are also presented.

Fracture toughness evaluations of TP304 stainless steel pipes

International Nuclear Information System (INIS)

Rudland, D.L.; Brust, F.W.; Wilkowski, G.M.

1997-02-01

In the IPIRG-1 program, the J-R curve calculated for a 16-inch nominal diameter, Schedule 100 TP304 stainless steel (DP2-A8) surface-cracked pipe experiment (Experiment 1.3-3) was considerably lower than the quasi-static, monotonic J-R curve calculated from a C(T) specimen (A8-12a). The results from several related investigations conducted to determine the cause of the observed toughness difference are: (1) chemical analyses on sections of Pipe DP2-A8 from several surface-cracked pipe and material property specimen fracture surfaces indicate that there are two distinct heats of material within Pipe DP2-A8 that differ in chemical composition; (2) SEN(T) specimen experimental results indicate that the toughness of a surface-cracked specimen is highly dependent on the depth of the initial crack, in addition, the J-R curves from the SEN(T) specimens closely match the J-R curve from the surface-cracked pipe experiment; (3) C(T) experimental results suggest that there is a large difference in the quasi-static, monotonic toughness between the two heats of DP2-A8, as well as a toughness degradation in the lower toughness heat of material (DP2-A8II) when loaded with a dynamic, cyclic (R = -0.3) loading history

Numerical Investigation of Ice Slurry Flow in a Horizontal Pipe

Science.gov (United States)

Rawat, K. S.; Pratihar, A. K.

2018-02-01

In the last decade, phase changing material slurry (PCMS) gained much attention as a cooling medium due to its high energy storage capacity and transportability. However the flow of PCM slurry is a complex phenomenon as it affected by various parameters, i.e. fluid properties, velocity, particle size and concentration etc.. In the present work ice is used as a PCM and numerical investigation of heterogeneous slurry flow has been carried out using Eulerian KTGF model in a horizontal pipe. Firstly the present model is validated with existing experiment results available in the literature, and then model is applied to the present problem. Results show that, flow is almost homogeneous for ethanol based ice slurry with particle diameter of 0.1 mm at the velocity of 1 m/s. It is also found that ice particle distribution is more uniform at higher velocity, concentration of ice and ethanol in slurry. Results also show that ice concentration increases on the top of the pipe, and the effect of particle wall collision is more significant at higher particle diameter.

A novel numerical model for estimating the collapse pressure of flexible pipes

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Victor P.P.; Antoun Netto, Theodoro [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao em Engenharia], e-mail: victor@lts.coppe.ufrj.br

2009-07-01

As the worldwide oil and gas industry operational environments move to ultra-deep waters, failure mechanisms in flexible pipes such as instability of the armor layers under compression and hydrostatic collapse are more likely to occur. Therefore, it is important to develop reliable numerical tools to reproduce the failure mechanisms that may occur in flexible pipes. This work presents a representative finite element model of flexible pipe capable to reproduce its pre and post-collapse behavior under hydrostatic pressure. The model, developed in the scope of this work, uses beam elements and includes nonlinear kinematics and material behavior influences. The dependability of the numerical results is assessed in light of experimental tests on flexible pipes with 4 inches and 8 inches nominal diameter available in the literature (Souza, 2002). The applied methodology provided coherent values regarding the estimation of the collapse pressures and results have shown that the proposed model is capable to reproduce experimental results. (author)

Pipe support

International Nuclear Information System (INIS)

Pollono, L.P.

1979-01-01

A pipe support for high temperature, thin-walled piping runs such as those used in nuclear systems is described. A section of the pipe to be suppported is encircled by a tubular inner member comprised of two walls with an annular space therebetween. Compacted load-bearing thermal insulation is encapsulated within the annular space, and the inner member is clamped to the pipe by a constant clamping force split-ring clamp. The clamp may be connected to pipe hangers which provide desired support for the pipe

On the performance of air conditioner with heat pipe for cooling air in the condenser

Energy Technology Data Exchange (ETDEWEB)

Naphon, Paisarn, E-mail: paisarnn@swu.ac.t [Thermo-Fluids and Heat Transfer Enhancement Laboratory (TFHT), Department of Mechanical Engineering, Faculty of Engineering, Srinakharinwirot University, 63 Rangsit-Nakhornnayok Rd., Ongkharak, Nakhorn-Nayok 26120 (Thailand)

2010-11-15

Improvement of the air conditioning system performance by using the heat pipe for cooling air before entering the condenser is presented. In the experiment, the heat pipe is fabricated from the straight copper tube with the diameter and length of 10, 600 mm, respectively. The arrangements of the heat pipe sets are arranged in the staggered layout with the tube rows of 1, 2, 3. R134a refrigerant is used as working fluid in the heat pipe set for this present study. By comparing with a conventional air conditioning system, the air conditioning system with three rows of heat pipe gives the highest COP and EER with increasing of 6.4%, 17.5%, respectively. On the global warming and environment problems, the results of this study are expected to lead to guidelines that will allow the improved performance of the air conditioning systems which reduce its energy consumption.

On the performance of air conditioner with heat pipe for cooling air in the condenser

International Nuclear Information System (INIS)

Naphon, Paisarn

2010-01-01

Improvement of the air conditioning system performance by using the heat pipe for cooling air before entering the condenser is presented. In the experiment, the heat pipe is fabricated from the straight copper tube with the diameter and length of 10, 600 mm, respectively. The arrangements of the heat pipe sets are arranged in the staggered layout with the tube rows of 1, 2, 3. R134a refrigerant is used as working fluid in the heat pipe set for this present study. By comparing with a conventional air conditioning system, the air conditioning system with three rows of heat pipe gives the highest COP and EER with increasing of 6.4%, 17.5%, respectively. On the global warming and environment problems, the results of this study are expected to lead to guidelines that will allow the improved performance of the air conditioning systems which reduce its energy consumption.

A study on the heat transfer characteristics of a self-oscillating heat pipe

International Nuclear Information System (INIS)

Yoon, Seok Hun; Oh, Cheol; Choi, Jae Hyuk

2002-01-01

In this paper, the heat transfer characteristics of a self-oscillating heat pipe are experimentally investigated for the effect of various working fluid fill charge ratios and heat loads. The characteristics of temperature oscillations of the working fluid are also analysed based on chaotic dynamics. The heat pipe is composed of a heating section, a cooling section and an adiabatic section, and has a 0.002m internal diameter, a 0.34m length in each turn and consists of 19 turns. The heating and the cooling portion of each turn has a length of 70mm. A series of experiments was carried out to measure the temperature distributions and the pressure variations of the heat pipe. Furthermore, heat transfer performance, effective thermal conductivity, boiling heat transfer and condensation heat transfer coefficients are calculated for various operating conditions. Experimental results show the efficacy of this type of heat pipe

PCR-Based Seamless Genome Editing with High Efficiency and Fidelity in Escherichia coli

DEFF Research Database (Denmark)

Liu, Yilan; Yang, Maohua; Yan, Daojiang

2016-01-01

Efficiency and fidelity are the key obstacles for genome editing toolboxes. In the present study, a PCR-based tandem repeat assisted genome editing (TRAGE) method with high efficiency and fidelity was developed. The design of TRAGE is based on the mechanism of repair of spontaneous double...... for seamlessly deleting, substituting and inserting targeted genes using PCR products. The effects of different manipulations including sucrose addition time, subculture times in LB with sucrose and stages of inoculation on the efficiency were investigated. With our recommended procedure, seamless excision...... of cat-sacB cassette can be realized in 48 h efficiently. We believe that the developed method has great potential for seamless genome editing in E. coli....

Numerical simulation of X90 UOE pipe forming process

Science.gov (United States)

Zou, Tianxia; Ren, Qiang; Peng, Yinghong; Li, Dayong; Tang, Ding; Han, Jianzeng; Li, Xinwen; Wang, Xiaoxiu

2013-12-01

The UOE process is an important technique to manufacture large-diameter welding pipes which are increasingly applied in oil pipelines and offshore platforms. The forming process of UOE mainly consists of five successive operations: crimping, U-forming, O-forming, welding and mechanical expansion, through which a blank is formed into a pipe in a UOE pipe mill. The blank with an appropriate edge bevel is bent into a cylindrical shape by crimping (C-forming), U-forming and O-forming successively. After the O-forming, there is an open-seam between two ends of the plate. Then, the blank is welded by automatic four-electrode submerged arc welding technique. Subsequently, the welded pipe is expanded with a mechanical expander to get a high precision circular shape. The multiple operations in the UOE mill make it difficult to control the quality of the formed pipe. Therefore, process design mainly relies on experience in practical production. In this study, the UOE forming of an API X90 pipe is studied by using finite element simulation. The mechanical properties tests are performed on the API X90 pipeline steel blank. A two-dimensional finite element model under the hypothesis of plane strain condition is developed to simulate the UOE process according to data coming from the workshop. A kinematic hardening model is used in the simulation to take the Bauschinger effect into account. The deformation characteristics of the blank during the forming processes are analyzed. The simulation results show a significant coherence in the geometric configurations comparing with the practical manufacturing.

Fracture evaluation of a crack in the service water piping system to an emergency diesel generator

International Nuclear Information System (INIS)

Rudland, D.; Scott, P.; Rahman, S.; Wilkowski, G.

1995-01-01

A pipe fracture experiment was conducted on a section of 6-inch nominal diameter pipe which was degraded by microbiologically induced corrosion (MIC) at a circumferential girth weld. The pipe was a section of one of the service water piping system to one of the emergency diesel generators at the Haddam Neck (Connecticut Yankee) plant. The experimental results will help validate future ASME Section XI pipe flaw evaluation criteria for other than Class 1 piping. A critical aspect of this experiment was an assessment of the degree of conservatism embodied in the ASME definition of flaw size. The ASME flaw size definition assumes a rectangular shaped, constant depth flaw with a depth equal to its maximum depth for its entire length. Since most service flaws are very irregular in shape, this definition can be very conservative. Alternative equivalent flaw size definitions for irregular shaped flaws are explored in this paper. (author). 7 refs., 2 figs., 4 tabs

Seamless user experiences in a brand new library

KAUST Repository

Vijayakumar, J.K.

2012-01-01

In order to provide seamless user experiences, the brand new libraries are far better positioned. They do not have to manage much in print, at least for the journal section, but huge electronic collection accessible via Internet. They do not worry

Pipe clamp effects on thin-walled pipe design

International Nuclear Information System (INIS)

Lindquist, M.R.

1980-01-01

Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from a three-dimensional shell finite element pipe model with clamp loads applied over the clamp/pipe contact area are shown. Analyses performed to categorize clamp induced piping loads as primary or secondary in nature are described. The ELCLAMP Computer Code, which performs analyses at clamp locations combining clamp induced stresses with stresses from overall piping system loads, is discussed. Grouping and enveloping methods to reduce the number of individual clamp locations requiring analysis are described

Apparatus and method for pulsed laser deposition of materials on wires and pipes

Science.gov (United States)

Fernandez, Felix E.

2003-01-01

Methods and apparatuses are disclosed which allow uniform coatings to be applied by pulsed laser deposition (PLD) on inner and outer surfaces of cylindrical objects, such as rods, pipes, tubes, and wires. The use of PLD makes this technique particularly suitable for complex multicomponent materials, such as superconducting ceramics. Rigid objects of any length, i.e., pipes up to a few meters, and with diameters from less than 1 centimeter to over 10 centimeters can be coated using this technique. Further, deposition is effected simultaneously onto an annular region of the pipe wall. This particular arrangement simplifies the apparatus, reduces film uniformity control difficulties, and can result in faster operation cycles. In addition, flexible wires of any length can be continuously coated using the disclosed invention.

Automatic seismic support design of piping system by an object oriented expert system

International Nuclear Information System (INIS)

Nakatogawa, T.; Takayama, Y.; Hayashi, Y.; Fukuda, T.; Yamamoto, Y.; Haruna, T.

1990-01-01

The seismic support design of piping systems of nuclear power plants requires many experienced engineers and plenty of man-hours, because the seismic design conditions are very severe, the bulk volume of the piping systems is hyge and the design procedures are very complicated. Therefore we have developed a piping seismic design expert system, which utilizes the piping design data base of a 3 dimensional CAD system and automatically determines the piping support locations and support styles. The data base of this system contains the maximum allowable seismic support span lengths for straight piping and the span length reduction factors for bends, branches, concentrated masses in the piping, and so forth. The system automatically produces the support design according to the design knowledge extracted and collected from expert design engineers, and using design information such as piping specifications which give diameters and thickness and piping geometric configurations. The automatic seismic support design provided by this expert system achieves in the reduction of design man-hours, improvement of design quality, verification of design result, optimization of support locations and prevention of input duplication. In the development of this system, we had to derive the design logic from expert design engineers and this could not be simply expressed descriptively. Also we had to make programs for different kinds of design knowledge. For these reasons we adopted the object oriented programming paradigm (Smalltalk-80) which is suitable for combining programs and carrying out the design work

Effects of the inner mould material on the aluminium–316L stainless steel explosive clad pipe

International Nuclear Information System (INIS)

Guo, Xunzhong; Tao, Jie; Wang, Wentao; Li, Huaguan; Wang, Chen

2013-01-01

Highlights: ► Different mould materials were adopted to evaluate the effect of the constraint on the clad quality. ► The interface characteristics of clad pipe were analyzed for the different clad pipe. ► The clad pipes possess excellent bonding quality. - Abstract: The clad pipe played an important part in the pipeline system of the nuclear power industry. To prepare the clad pipe with even macrosize and excellent bonding quality, in this work, different mould materials were adopted to evaluate the effect of the constraint on the clad quality of the bimetal pipe prepared by explosive cladding. The experiment results indicated that, the dimension uniformity and bonding interface of clad pipe were poor by using low melting point alloy as mould material; the local bulge or the cracking of the clad pipe existed when the SiC powder was utilized. When the steel mould was adopted, the outer diameter of the clad pipe was uniform from head to tail. In addition, the metallurgical bonding was formed. Furthermore, the results of shear test, bending test and flattening test showed that the bonding quality was excellent. Therefore, the Al–316L SS clad pipe could endure the second plastic forming

Reliable pipeline repair system for very large pipe size

Energy Technology Data Exchange (ETDEWEB)

Charalambides, John N.; Sousa, Alexandre Barreto de [Oceaneering International, Inc., Houston, TX (United States)

2004-07-01

The oil and gas industry worldwide has been mainly depending on the long-term reliability of rigid pipelines to ensure the transportation of hydrocarbons, crude oil, gas, fuel, etc. Many other methods are also utilized onshore and offshore (e.g. flexible lines, FPSO's, etc.), but when it comes to the underwater transportation of very high volumes of oil and gas, the industry commonly uses large size rigid pipelines (i.e. steel pipes). Oil and gas operators learned to depend on the long-lasting integrity of these very large pipelines and many times they forget or disregard that even steel pipelines degrade over time and more often that that, they are also susceptible to various forms of damage (minor or major, environmental or external, etc.). Over the recent years the industry had recognized the need of implementing an 'emergency repair plan' to account for such unforeseen events and the oil and gas operators have become 'smarter' by being 'pro-active' in order to ensure 'flow assurance'. When we consider very large diameter steel pipelines such as 42' and 48' nominal pipe size (NPS), the industry worldwide does not provide 'ready-made', 'off-the-shelf' repair hardware that can be easily shipped to the offshore location and effect a major repair within acceptable time frames and avoid substantial profit losses due to 'down-time' in production. The typical time required to establish a solid repair system for large pipe diameters could be as long as six or more months (depending on the availability of raw materials). This paper will present in detail the Emergency Pipeline Repair Systems (EPRS) that Oceaneering successfully designed, manufactured, tested and provided to two major oil and gas operators, located in two different continents (Gulf of Mexico, U.S.A. and Arabian Gulf, U.A.E.), for two different very large pipe sizes (42'' and 48'' Nominal Pipe Sizes

"Seamlessly" Learning Chinese: Contextual Meaning Making and Vocabulary Growth in a Seamless Chinese as a Second Language Learning Environment

Science.gov (United States)

Wong, Lung-Hsiang; King, Ronnel B.; Chai, Ching Sing; Liu, May

2016-01-01

Second language learners are typically hampered by the lack of a natural environment to use the target language for authentic communication purpose (as a means for "learning by applying"). Thus, we propose MyCLOUD, a mobile-assisted seamless language learning approach that aims to nurture a second language social network that bridges…

Mobile Seamless Technology Enhanced CSL Oral Communication

Science.gov (United States)

Lan, Yu-Ju; Lin, Yen-Ting

2016-01-01

The current study aimed at investigating how mobile seamless technology can be used to enhance the pragmatic competence of learners of Chinese as a second language (CSL). 34 overseas CSL learners participated in this study. They were randomly assigned into two groups: the classroom group, executing language tasks in fake contexts in a traditional…

New application technology for 'in situ' pipeline protection using pigging techniques

Energy Technology Data Exchange (ETDEWEB)

Pretorius, Louis Charles [Corrocoat SA (PTY) Ltd., Durban (South Africa)

2005-07-01

Pigging of long pipelines is a technique for in situ (field) coating, creating seamless internal structural linings. Originally developed for cleaning pipes, the system was adapted to apply internal anti-corrosion protection to pipes using a thin epoxy layer, which had some problems in weld coverage, stress cracking, poor cold weather curing and the inability to fill pitting corrosion metal loss. New coating materials, revised application methods and modified pigging equipment have made it possible to apply in situ liquid film coatings up to 1 mm thick, as an internal corrosion barrier to pipes, in a single application (similar to continuous screeding) resulting in a bonded 'GRP pipe within a steel pipe'. The method can be used for new projects on fully welded pipe lines avoiding coating problems associated with flange joints and/or couplings, or for refurbishment of old pipelines, varying from 150-900 mm diameter, up to 12 km long. Pipes can be buried, submerged, continuously welded or flanged. Many different pipes, such as oil platform to shore based pipelines, can all be treated using this method. Thick film polymer pigging techniques create new possibilities for Engineers to extend the life of pipeline systems, with significant cost savings compared to replacement pipe. (author)

Determination of the modulus of soil reactions for small diameter plastic pipes; Determinacao do modulo de reacao do solo para dutos plasticos de pequeno diametro

Energy Technology Data Exchange (ETDEWEB)

Costa, Yuri D. [Costa-Lins Consultoria Geotecnica (Brazil)]. E-mail: ydjcosta@sc.usp.br; Bueno, Benedito S. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia]. E-mail: bsbueno@sc.usp.br

2005-07-01

The evaluation of the deflection of buried pipes is often impaired by the selection of reliable design values for the modulus of soil reaction (E'), which is available from a limited number of sources in the literature. This paper presents results of E' from a series of laboratory tests comprising plastic pipes embedded in a granular soil. E' was determined from measurements of the pipe deflections and the stresses in the soil mass at the spring line of the pipe. Measurements of the pipe deflections involved the development of a transducer device capable of measuring radial displacements in selected positions around the transverse section of the pipe. Investigations of the effects of depth of embedment and degree of soil compaction on E' were accomplished with the developed testing program. Previsions of the pipe deflection using the Iowa Formula and the analytical solution of Burns and Richard (1964) were compared with the experimental results. Very good agreement was obtained between the experimental results and the solution of Burns and Richard (1964) incorporating experimental E' values as input data. The analyses were further extended to the suggestion of replacing E' by the confined compression modulus of the surrounding soil. (author)

Seamless Synthetic Aperture Radar Archive for Interferometry Analysis

Science.gov (United States)

Baker, S.; Baru, C.; Bryson, G.; Buechler, B.; Crosby, C.; Fielding, E.; Meertens, C.; Nicoll, J.; Youn, C.

2014-11-01

The NASA Advancing Collaborative Connections for Earth System Science (ACCESS) seamless synthetic aperture radar (SAR) archive (SSARA) project is a collaboration between UNAVCO, the Alaska Satellite Facility (ASF), the Jet Propulsion Laboratory (JPL), and OpenTopography at the San Diego Supercomputer Center (SDSC) to design and implement a seamless distributed access system for SAR data and derived interferometric SAR (InSAR) data products. A unified application programming interface (API) has been created to search the SAR archives at ASF and UNAVCO, 30 and 90-m SRTM DEM data available through OpenTopography, and tropospheric data from the NASA OSCAR project at JPL. The federated query service provides users a single access point to search for SAR granules, InSAR pairs, and corresponding DEM and tropospheric data products from the four archives, as well as the ability to search and download pre-processed InSAR products from ASF and UNAVCO.

Single-Phase Microgrid with Seamless Transition Capabilities between Modes of Operation

DEFF Research Database (Denmark)

Micallef, Alexander; Apap, Maurice; Spiteri-Staines, Cyril

2015-01-01

with the secondary control loops that are used to synchronize the microgrid as a single unit to the grid. Simulation results are given that show the seamless transitions between the two modes without any disconnection times for the CC-VSIs and VC-VSIs connected to the microgrid.......Microgrids are an effective way to increase the penetration of DG into the grid. They are capable of operating either in grid-connected or in islanded mode thereby increasing the supply reliability for the end user. This paper focuses on achieving seamless transitions from islanded to grid-connected...

Methodology to translate policy assessment problems into scenarios: the example of the SEAMLESS integrated framework

NARCIS (Netherlands)

Therond, O.; Belhouchette, H.; Janssen, S.J.C.; Louhichi, K.; Ewert, F.; Bergez, J.E.; Wery, J.; Heckelei, T.; Olsson, J.A.; Leenhardt, D.; Ittersum, van M.K.

2009-01-01

Scenario-based approaches in environmental and policy assessment studies are increasingly applied within integrated assessment and modelling frameworks. The SEAMLESS project develops such an integrated framework (SEAMLESS-IF) aiming to assess, ex-ante, impacts of alternative agro-environmental

DEM study of granular discharge rate through a vertical pipe with a bend outlet in small absorber sphere system

Energy Technology Data Exchange (ETDEWEB)

Li, Tianjin, E-mail: tjli@tsinghua.edu.cn; Zhang, He; Liu, Malin; Huang, Zhiyong; Bo, Hanliang; Dong, Yujie

2017-04-01

Highlights: • The work concerns granular flow in a vertical pipe with a bend. • Discharge rate fluctuation in vertical pipe are mainly from velocity fluctuation. • Steady discharge rate decreases rapidly and saturates with μ{sub s} increasing. • Steady discharge rate W{sub s} still obey the 5/2 power law of pipe internal diameter. • A correlation developed for steady discharge rate for this new geometry. - Abstract: Absorber sphere pneumatic conveying is a special application of pneumatic conveying technique in the pebble bed High Temperature Gas-Cooled Reactor (HTGR or HTR). Granular discharge through a vertical pipe with a bend outlet is one of the control modes to determine solid mass flowrate which is an important parameter for the design of absorber sphere pneumatic conveying. Granular discharge rate through the vertical pipe with a bend outlet in the small absorber sphere system are investigated by discrete element method simulation. The effect of geometry parameters on discharge rate, the discharge rate fluctuation in the vertical pipe, and the effect of friction on steady discharge rate (W{sub s}) are analyzed and discussed. The phenomena of discharge rate fluctuation in the vertical pipe are observed, which are mainly resulted from the evolution of the average downward granular velocity. The steady discharge rate decreases rapidly with sliding friction coefficient increasing from 0.125 to 0.5, and gradually saturates with the friction coefficient further increasing from 0.5 to 1. It is interesting that the linear relation between W{sub s}{sup 2/5} and pipe internal diameter D with zero intercept are found for the vertical pipe discharge with a bend outlet, which is different from the orifice discharge through a hopper or silo with none-zero intercept. A correlation similar to Beverloo’s correlation is developed to predict the steady discharge rate through the vertical pipe with a bend outlet. These results are helpful for the design of sphere

The residual stress distribution in welded pipe inner surface of stainless steel from the nuclear power plant in Ringhals

International Nuclear Information System (INIS)

Larsson, L.E.

1984-06-01

The axial residual stress distribution on the inner surface of welded pipes of stainless steel SS 2333 (AISI 304) have been measured using the X-ray diffraction technique. Four halves of two pipes with the outer diameter of 114 mm and wall thickness of 10 mm were investigated. The result on the pipe inner surface shows compressive stresses in the weld metal and tensile stresses within a region between 8-23 mm with a maximum of 180MPa at a distance of 17 mm from the weld centerline. The maximum axial and circumferential residual stresses on the pipe outer surface are of the magnitude of 100 MPa. By cutting the pipes into two halves these stresses are relaxed by about 35 MPa. (author)

Optimization of Wellhead Piping Design for Production Wells at Development of Steam-Water Geothermal Fields

Directory of Open Access Journals (Sweden)

A.N. Shulyupin

2017-03-01

Full Text Available At present, the exploitation of geothermal resources develops in a fair competition with other types of energy resources. This leads to actuality of questions which associated with the more efficient use of existing wells, because cost of their drilling is a significant share of geothermal projects. In domestic practice of development of geothermal resources the steam-water wells have greatest energy potential. One way to improve the performance of these wells is a providing of smooth change of direction of motion of steam-water mixture from the vertical, in the well, to the horizontal, in steam gathering system. Typical wellhead piping of domestic steam-water wells involves the removal of the mixture through a cross bar at a right angle. Cross bar can generate considerable pressure loss that increases the operating pressure at the mouth of the well and reduces flow rate. It seems reasonable to substitute the typical cross bar by smooth pipe bend. This reduces wellhead resistance coefficient by more than on 2. Increase of curvature radius of pipe bend reduces the pressure loss to a local resistance but increases the friction pressure loss. There is an optimal curvature radius of pipe bend for minimum pressure loss in view of a local resistance and friction in the pipe bend. Calculations have shown that the optimum value for the radius of curvature is found in the range from 1.4 to 4.5 tube internal diameters. However, for technological reasons it is recommended to choose the radius of curvature from 1.4 to 2.4 diameters. Mounting of smooth pipe bend on the wellhead can provide significant economic benefits. For Mutnovka field (Kamchatka, this effect is estimated at 17.5 million rubles in year.

Seamless communication in supply chains based on M2M technology

Directory of Open Access Journals (Sweden)

Walid Moneimne

2016-12-01

Full Text Available Background: Access to information is the key element in the successful and efficient organization of transport & logistic processes. The importance of real-time access to information is confirmed by a panel workshop carried out with support of design thinking methodology. There are two ways of gaining access to the right information - manual, where human agency is needed and fully automatic, where new M2M technology is implemented. Implementation of such technology improves seamless communication during transport execution and allows real-time access to needed information. The aim of the paper is to evaluate the influence of the effectiveness of using M2M technology and traditional way of communication as well as data gathering in order to ensure seamless communication in the supply chain. Methods: Survey, design thinking, desk research and real case study results were used in the paper. Results and conclusions: Seamless communication and implementation of M2M technology within the whole supply (including modes of transport and transport units chain is a backbone of the lean and reliable digital supply chain.

Effect of Polymer Type and Mixing of Polymers on Drag Reduction in Turbulent Pipe Flow

Directory of Open Access Journals (Sweden)

Salam Hadi Hussein

2017-05-01

Full Text Available The paper reports on studies on effect of the type of polymer on drag reduction. The study conducted through circular pipe using Carboxy Methyl Cellulose (CMC, Xanthan gum (XG and their mixing in equal ratios as additives in pipe of diameter 0.0381m. The study covered range of parameters like concentration, mean velocity and angle of inclination of pipe. The maximum drag reduction observed was about 58%, 46% and 46% for the three polymers respectively. It is found that the drag reduction for the mixture is close to the drag reduction for XG polymer. The SPSS program has been used for correlate the data that have been obtained. The drag reduction percentage is correlated in terms of Reynolds number Re, additive concentration C (ppm and angle of inclination of pipe (deg, and the relations obtained is mentioned.

Failure analysis of cracked head spray piping from the Dresden Unit 2 Boiling Water Reactor

International Nuclear Information System (INIS)

Diercks, D.R.; Dragel, G.M.

1983-07-01

Several sections of Type 304 stainless steel head spray piping, 6.25 cm (2.5 in.) in diameter, from the Dresden Unit 2 Boiling Water Reactor were examined to determine the nature and causes of coolant leakages detected during hydrostatic tests. Extensive pitting was observed on the outside surface of the piping, and three cracks, all located at a helical stripe apparently rubbed onto the outer surface of the piping, were also noted. Metallographic examination revealed that the cracking had initiated at the outer surface of the pipe, and showed it to be transgranular and highly branched, characteristic of chloride stress corrosion cracking. The surface pitting also appeared to have been caused by chlorides. A scanning electron microprobe x-ray analysis of the corrosion product in the cracks confirmed the presence of chlorides and also indicated the presence of calcium

Development of two-phase flow along a large vertical pipe

International Nuclear Information System (INIS)

Dirk Lucas; Prasser, H.M.

2005-01-01

Full text of publication follows: To qualify CFD codes for two-phase flow simulations, closure laws describing the interaction between the phases are needed. Vertical pipe flow is a suitable object for studying the corresponding phenomena in case of dispersed bubbly flow. Here, the bubbles move under clear boundary conditions, resulting in a shear field of nearly constant structure where the bubbles rise for a comparatively long time. This allows to study the lateral motion of the bubbles in a shear flow as well as bubble coalescence and break-up by comparing gas volume fraction distributions and bubble size distributions at different heights. Very detailed data were obtained at the TOPFLOW facility of the Forschungszentrum Rossendorf using an advanced wire-mesh sensor. This sensor measures the instantaneous conductivity distribution over the pipe cross section. The high frequency of the measurement (2500 frames/s) allows the detection of single bubbles by a special evaluation procedure. Bubble size distributions, gas volume fraction distributions and also gas fraction distributions decomposed according to the bubble size are delivered as result of the evaluation procedure. The use of two sensors allows to measure the profile of the gas velocity. In previous works similar data for pipe of 51.2 mm inner diameter were used for the validation of non-drag bubble forces [1] and the evaluation of the influence of radial profiles on the development of the flow pattern [2]. First investigations on scaling effects were done using data obtained at a pipe with an inner diameter of 194 mm [3]. A constant distance between gas injection and measuring plane of L/D ∼ 40 was used. From a new test series now measurements are available for varying distances between the injection device and the wire-mesh sensor. This allows the evaluation of the development of the flow along the pipe. The data are used for the development and validation of mesoscale models for the forces acting on

Nuclear piping and pipe support design and operability relating to loadings and small bore piping

International Nuclear Information System (INIS)

Stout, D.H.; Tubbs, J.M.; Callaway, W.O.; Tang, H.T.; Van Duyne, D.A.

1994-01-01

The present nuclear piping system design practices for loadings, multiple support design and small bore piping evaluation are overly conservative. The paper discusses the results developed for realistic definitions of loadings and loading combinations with methodology for combining loads under various conditions for supports and multiple support design. The paper also discusses a simplified method developed for performing deadweight and thermal evaluations of small bore piping systems. Although the simplified method is oriented towards the qualification of piping in older plants, this approach is applicable to plants designed to any edition of the ASME Section III or B31.1 piping codes

Investigation and evaluation of stress-corrosion cracking in piping of light water reactor plants

International Nuclear Information System (INIS)

1979-01-01

In 1975, a Pipe Cracking Study Group, established by the United States Nuclear Regulatory Commission (USNRC), reviewed intergranular stress-corrosion cracking (IGSCC) in Bioling Water Reactors (BWRs) and issued a report. During 1978, IGSCC was reported for the first time in large-diameter piping (> 20 in.) in a BWR in Germany. This discovery, together with the reported questions concerning the interpretation of ultrasonic inspections, led to the activation of a new Pipe Crack Study Group (PCSG) by USNRC. The charter of the new PCSG was expanded: (1) to include review of potential for stress-corrosion cracking in Pressurized Water Reactors (PWRs) as well as BWRs, (2) to examine operating experience in foreign reactors relevant to IGSCC, and (3) to study five specific questions. The PCSG limited the scope of the study to BWR and PWR piping runs and safe ends attached to the reactor pressure vessel. Not considered were components such as the reactor pressure vessel, pumps, valves, steam generators, large steam turbines, etc. Throughout this report, as well as in the title, the safe ends are arbitrarily defined as piping

Numerical study of heat and mass transfer in inertial suspensions in pipes.

Science.gov (United States)

Niazi Ardekani, Mehdi; Brandt, Luca

2017-11-01

Controlling heat and mass transfer in particulate suspensions has many important applications such as packed and fluidized bed reactors and industrial dryers. In this work, we study the heat and mass transfer within a suspension of spherical particles in a laminar pipe flow, using the immersed boundary method (IBM) to account for the solid fluid interactions and a volume of fluid (VoF) method to resolve temperature equation both inside and outside of the particles. Tracers that follow the fluid streamlines are considered to investigate mass transfer within the suspension. Different particle volume fractions 5, 15, 30 and 40% are simulated for different pipe to particle diameter ratios: 5, 10 and 15. The preliminary results quantify the heat and mass transfer enhancement with respect to a single-phase laminar pipe flow. We show in particular that the heat transfer from the wall saturates for volume fractions more than 30%, however at high particle Reynolds numbers (small diameter ratios) the heat transfer continues to increase. Regarding the dispersion of tracer particles we show that the diffusivity of tracers increases with volume fraction in radial and stream-wise directions however it goes through a peak at 15% in the azimuthal direction. European Research Council, Grant No. ERC-2013-CoG- 616186, TRITOS; SNIC (the Swedish National Infrastructure for Computing).

An Open Platform for Seamless Sensor Support in Healthcare for the Internet of Things

Directory of Open Access Journals (Sweden)

Jorge Miranda

2016-12-01

Full Text Available Population aging and increasing pressure on health systems are two issues that demand solutions. Involving and empowering citizens as active managers of their health represents a desirable shift from the current culture mainly focused on treatment of disease, to one also focused on continuous health management and well-being. Current developments in technological areas such as the Internet of Things (IoT, lead to new technological solutions that can aid this shift in the healthcare sector. This study presents the design, development, implementation and evaluation of a platform called Common Recognition and Identification Platform (CRIP, a part of the CareStore project, which aims at supporting caregivers and citizens to manage health routines in a seamless way. Specifically, the CRIP offers sensor-based support for seamless identification of users and health devices. A set of initial requirements was defined with a focus on usability limitations and current sensor technologies. The CRIP was designed and implemented using several technologies that enable seamless integration and interaction of sensors and people, namely Near Field Communication and fingerprint biometrics for identification and authentication, Bluetooth for communication with health devices and web services for wider integration with other platforms. Two CRIP prototypes were implemented and evaluated in laboratory during a period of eight months. The evaluations consisted of identifying users and devices, as well as seamlessly configure and acquire vital data from the last. Also, the entire Carestore platform was deployed in a nursing home where its usability was evaluated with caregivers. The evaluations helped assess that seamless identification of users and seamless configuration and communication with health devices is feasible and can help enable the IoT on healthcare applications. Therefore, the CRIP and similar platforms could be transformed into a valuable enabling

An Open Platform for Seamless Sensor Support in Healthcare for the Internet of Things

Science.gov (United States)

Miranda, Jorge; Cabral, Jorge; Wagner, Stefan Rahr; Fischer Pedersen, Christian; Ravelo, Blaise; Memon, Mukhtiar; Mathiesen, Morten

2016-01-01

Population aging and increasing pressure on health systems are two issues that demand solutions. Involving and empowering citizens as active managers of their health represents a desirable shift from the current culture mainly focused on treatment of disease, to one also focused on continuous health management and well-being. Current developments in technological areas such as the Internet of Things (IoT), lead to new technological solutions that can aid this shift in the healthcare sector. This study presents the design, development, implementation and evaluation of a platform called Common Recognition and Identification Platform (CRIP), a part of the CareStore project, which aims at supporting caregivers and citizens to manage health routines in a seamless way. Specifically, the CRIP offers sensor-based support for seamless identification of users and health devices. A set of initial requirements was defined with a focus on usability limitations and current sensor technologies. The CRIP was designed and implemented using several technologies that enable seamless integration and interaction of sensors and people, namely Near Field Communication and fingerprint biometrics for identification and authentication, Bluetooth for communication with health devices and web services for wider integration with other platforms. Two CRIP prototypes were implemented and evaluated in laboratory during a period of eight months. The evaluations consisted of identifying users and devices, as well as seamlessly configure and acquire vital data from the last. Also, the entire Carestore platform was deployed in a nursing home where its usability was evaluated with caregivers. The evaluations helped assess that seamless identification of users and seamless configuration and communication with health devices is feasible and can help enable the IoT on healthcare applications. Therefore, the CRIP and similar platforms could be transformed into a valuable enabling technology for secure and

An Open Platform for Seamless Sensor Support in Healthcare for the Internet of Things.

Science.gov (United States)

Miranda, Jorge; Cabral, Jorge; Wagner, Stefan Rahr; Fischer Pedersen, Christian; Ravelo, Blaise; Memon, Mukhtiar; Mathiesen, Morten

2016-12-08

Population aging and increasing pressure on health systems are two issues that demand solutions. Involving and empowering citizens as active managers of their health represents a desirable shift from the current culture mainly focused on treatment of disease, to one also focused on continuous health management and well-being. Current developments in technological areas such as the Internet of Things (IoT), lead to new technological solutions that can aid this shift in the healthcare sector. This study presents the design, development, implementation and evaluation of a platform called Common Recognition and Identification Platform (CRIP), a part of the CareStore project, which aims at supporting caregivers and citizens to manage health routines in a seamless way. Specifically, the CRIP offers sensor-based support for seamless identification of users and health devices. A set of initial requirements was defined with a focus on usability limitations and current sensor technologies. The CRIP was designed and implemented using several technologies that enable seamless integration and interaction of sensors and people, namely Near Field Communication and fingerprint biometrics for identification and authentication, Bluetooth for communication with health devices and web services for wider integration with other platforms. Two CRIP prototypes were implemented and evaluated in laboratory during a period of eight months. The evaluations consisted of identifying users and devices, as well as seamlessly configure and acquire vital data from the last. Also, the entire Carestore platform was deployed in a nursing home where its usability was evaluated with caregivers. The evaluations helped assess that seamless identification of users and seamless configuration and communication with health devices is feasible and can help enable the IoT on healthcare applications. Therefore, the CRIP and similar platforms could be transformed into a valuable enabling technology for secure and

Investigation of guided waves propagation in pipe buried in sand

International Nuclear Information System (INIS)

Leinov, Eli; Cawley, Peter; Lowe, Michael J.S.

2014-01-01

The inspection of pipelines by guided wave testing is a well-established method for the detection of corrosion defects in pipelines, and is currently used routinely in a variety of industries, e.g. petrochemical and energy. When the method is applied to pipes buried in soil, test ranges tend to be significantly compromised because of attenuation of the waves caused by energy radiating into the soil. Moreover, the variability of soil conditions dictates different attenuation characteristics, which in-turn results in different, unpredictable, test ranges. We investigate experimentally the propagation and attenuation characteristics of guided waves in pipes buried in fine sand using a well characterized full scale experimental apparatus. The apparatus consists of an 8 inch-diameter, 5.6-meters long steel pipe embedded over 3 meters of its length in a rectangular container filled with fine sand, and an air-bladder for the application of overburden pressure. Longitudinal and torsional guided waves are excited in the pipe and recorded using a transducer ring (Guided Ultrasonics Ltd). Acoustic properties of the sand are measured independently in-situ and used to make model predictions of wave behavior in the buried pipe. We present the methodology and the systematic measurements of the guided waves under a range of conditions, including loose and compacted sand. It is found that the application of overburden pressure modifies the compaction of the sand and increases the attenuation, and that the measurement of the acoustic properties of sand allows model prediction of the attenuation of guided waves in buried pipes with a high level of confidence

TransCanada PipeLines Limited 1998 annual report : TransCanada energy solutions

International Nuclear Information System (INIS)

1999-01-01

Financial information from TransCanada PipeLines Limited and a review of the company's 1998 operations was made available for the benefit of shareholders. TransCanada's pipeline system transports natural gas and crude oil from Western Canada Sedimentary Basin to North America's major energy markets. Net earnings from continuing operations for 1998, before unusual charges, were $575 million ($ 355 million after unusual charges) compared to $522 million for 1997. Solid performances from the energy transmission and international business, when compared to 1997, were more than offset by a decreased contribution from energy processing. TransCanada recorded integration costs of $166 million, after tax, related to the merger with NOVA in 1998, which was the major operational accomplishment during the year, creating a seamless economic energy delivery, processing and marketing system from the wellhead to the market. tabs., figs

Seamless service: research and action.

Science.gov (United States)

Grinstead, N; Timoney, R

1994-01-01

Describes the process used by the Mater Infirmorum Hospital in Belfast in 1992-1994 to achieve high quality care (Seamless Service), and motivate staff to deliver and measure performance. Aims of the project include focusing the organization on the customer, improving teamwork and motivation at all levels. After comprehensive data collection from GPs, patients and staff forums developed a full TQM strategy to gain support and maintain momentum including innovative staff events (every staff member was given the opportunity to attend) where multilevel, multidisciplinary workshops enabled staff to design customer care standards, develop teams and lead customer-driven change.

Experiments on hydraulically-compensated Compressed Air Energy Storage (CAES) system using large-diameter vertical pipe two-phase flow test facility: test facility and test procedure

International Nuclear Information System (INIS)

Ohtsu, Iwao; Murata, Hideo; Kukita, Yutaka; Kumamaru, Hiroshige.

1996-07-01

JAERI, the University of Tokyo, the Central Research Institute of Electric Power Industry and Shimizu Corporation jointing performed and experimental study on two-phase flow in the hydraulically-compensated Compressed Air Energy Storage (CAES) system with a large-diameter vertical pipe two-phase flow test facility from 1993 to 1995. A hydraulically-compensated CAES system is a proposed, conceptual energy storage system where energy is stored in the form of compressed air in an underground cavern which is sealed by a deep (several hundred meters) water shaft. The shaft water head maintains a constant pressure in the cavern, of several mega Pascals, even during loading or unloading of the cavern with air. The dissolved air in the water, however, may create voids in the shaft when the water rises through the shaft during the loading, being forced by the air flow into the cavern. The voids may reduce the effective head of the shaft, and thus the seal may fail, if significant bubbling should occur in the shaft. This bubbling phenomenon (termed 'Champaign effect') and potential failure of the water seal ('blowout') are simulated in a scaled-height, scaled-diameter facility. Carbon dioxide is used to simulate high solubility of air in the full-height, full-pressure system. This report describes the expected and potential two-phase flow phenomena in a hydraulically-compensated CAES system, the test facility and the test procedure, a method to estimate quantities which are not directly measured by using measured quantities and hydrodynamic basic equations, and desirable additional instrumentation. (author)

The use of radiography for thickness measurement and corrosion monitoring in pipes

International Nuclear Information System (INIS)

Edalati, K.; Rastkhah, N.; Kermani, A.; Seiedi, M.; Movafeghi, A.

2006-01-01

In this study of pipes of 150 mm diameters, thickness ranging from 4.2 to 15.0 mm was determined by using two radiography techniques: tangential radiography and double wall radiography. It was concluded that thickness losses of 10%, 20% and 50% could be determined by these methods. Formulae were developed for the double wall radiography method with a high precision of thickness measurement for non-insulated pipes. The precision was comparable with ultrasonic measurement results. Corrosion type and corrosion surface could be observed by these methods. Internal or external corrosion produced different effects in tangential radiography. Insulation removal was not necessary using the radiographic techniques

The use of radiography for thickness measurement and corrosion monitoring in pipes

Energy Technology Data Exchange (ETDEWEB)

Edalati, K. [Department of NDT, Nuclear Safety and Radiation Protection Technological Centre, AEOI, P.O. Box 14155-1399, Tehran (Iran, Islamic Republic of)]. E-mail: NDT99@aeoi.org.ir; Rastkhah, N. [Department of NDT, Nuclear Safety and Radiation Protection Technological Centre, AEOI, P.O. Box 14155-1399, Tehran (Iran, Islamic Republic of); Kermani, A. [Department of NDT, Nuclear Safety and Radiation Protection Technological Centre, AEOI, P.O. Box 14155-1399, Tehran (Iran, Islamic Republic of); Seiedi, M. [Department of NDT, Nuclear Safety and Radiation Protection Technological Centre, AEOI, P.O. Box 14155-1399, Tehran (Iran, Islamic Republic of); Movafeghi, A. [Department of NDT, Nuclear Safety and Radiation Protection Technological Centre, AEOI, P.O. Box 14155-1399, Tehran (Iran, Islamic Republic of)

2006-10-15

In this study of pipes of 150 mm diameters, thickness ranging from 4.2 to 15.0 mm was determined by using two radiography techniques: tangential radiography and double wall radiography. It was concluded that thickness losses of 10%, 20% and 50% could be determined by these methods. Formulae were developed for the double wall radiography method with a high precision of thickness measurement for non-insulated pipes. The precision was comparable with ultrasonic measurement results. Corrosion type and corrosion surface could be observed by these methods. Internal or external corrosion produced different effects in tangential radiography. Insulation removal was not necessary using the radiographic techniques.

Experimental investigations on bubble turbulent diffusion in a vertical large diameter pipe by means of wire-mesh sensors and correlation techniques

International Nuclear Information System (INIS)

Annalisa Manera; Horst-Michael Prasser; Dirk Lucas

2005-01-01

Full text of publication follows: A large number of experiments for water-air vertical flows in a large-diameter pipe has been carried out at the TOPFLOW facility (Forschunszentrum Rossendorf). The experiments cover a wide range of liquid and superficial gas velocity. The test section consists of a vertical pipe of ∼194 mm and 8.5 m long. At a distance of 7.6 m from the air injection, two wire-mesh sensors are installed. The two sensors are mounted at a distance of 63.3 mm from each other. The wire-mesh sensors measure sequences of instantaneous two-dimensional gas-fraction distributions in the cross-section in which they are mounted with a spatial resolution of 3 mm and a frequency of 2500 Hz. The total dimension of the matrix of measuring points for each mesh sensor is 64 x 64. In a central region of the measuring plane, where the void-fraction gradients are small, points of the first wire-mesh sensor are individually cross-correlated in time domain with measuring points belonging to the second wire-mesh sensor. The cross-correlation functions were calculated for pairs of points that are located accurately above each other as well as for points with a lateral distance. The lateral distance was varied from 0 to 48 mm (16 points), which is still within 50% of the pipe radius, i.e. in the region of small void-fraction gradients. The maximum of each of the 17 correlations is selected in order to derive a spatial correlation in the radial direction. The obtained spatial cross-correlations shows a maximum at zero lateral distance and decrease with growing lateral shift. In a region without gradients, the lateral displacement of bubbles is dominated by turbulent diffusion. This gives the opportunity to derive bubble turbulent diffusion coefficients from the spreading of the spatial correlations. At this aim, the spatial correlations have been first corrected to take into account the finite spatial resolution of the sensor and the finite dimension of the bubbles. The

LMFBR flexible pipe joint development program. Annual technical progress report, government fiscal year 1977

International Nuclear Information System (INIS)

1978-01-01

Currently, the ASME Boiler and Pressure Vessel Code does not allow the use of flexible pipe joints (bellows) in Section III, Class 1 reactor primary piping systems. Studies have shown that the primary piping loops of LMFBR's could be simplified by using these joints. This simplification translates directly into shorter primary piping runs and reduced costs for the primary piping system. Further cost savings result through reduced vault sizes and reduced containment building diameter. In addition, the use of flexible joints localizes the motions from thermally-induced piping growth into components which are specifically designed to accommodate this motion. This reduces the stress levels in the piping system and its components. It is thus economically and structurally important that flexible piping joints be available to the LMFBR designer. The overall objective of the Flexible Joint Program is to provide this availability. This will be accomplished through the development of ASME rules which allow the appropriate use of such joints in Section III, Class 1 piping systems and through the development and demonstration of construction methods which satisfy these rules. The rule development includes analytic and testing methodology formulations which will be supported by subscale bellows testing. The construction development and demonstration encompass the design, fabrication, and in-sodium testing of prototypical LMFBR plant-size flexible pipe joints which meet all ASME rule requirements. The satisfactory completion of these developmental goals will result in an approved flexible pipe joint design for the LMFBR. Progress is summarized in the following efforts undertaken during 1977 to accomplish these goals: (1) code case support, (2) engineering and design, (3) material development, (4) testing, and (5) manufacturing development

Revisited the mathematical derivation wall thickness measurement of pipe for radiography

Energy Technology Data Exchange (ETDEWEB)

Hamzah, A.R.; Amir, S.M.M. [Non Destructive Testing(NDT) Group, Industrial Technology Div., Malaysian Nuclear Agency, Selangor (Malaysia)

2007-07-01

Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the Pythagoras theorem and geometrical principles. In order to derive the maximum penetration wall thickness a similar approach is used. (authors)

Fatigue evaluation of piping connections under thermal transients

International Nuclear Information System (INIS)

Aquino, C.T.E. de; Maneschy, J.E.

1993-01-01

In designing nuclear power plant piping, thermal transients, caused by non-steady operation conditions, should be considered. These events may reduce considerably the lifetime of the pipes, creating the necessity of using structural elements designed in such a way to minimize the acting thermal stresses. Typical examples of the usage of these elements are the connections between pipes of small and large diameters, in which it is usually used a weldolet. Nevertheless, in some situations, the thermal stresses caused by the transients are greater than the allowable limits, being, in this case, an alternative for best results, the introduction of a special fitting replacing the weldolet. Such a fitting is designed in a way to permit a better distribution of the stresses, reducing its maximum value to acceptable levels. This paper intends to present a fatigue evaluation of a connection, using the above mentioned fitting, when subjected to a load expressed in terms of a step thermal gradient, varying from 263 deg to 40 deg C. Two different methodologies are used in this analysis: (a) Determination of the temperature distribution from the heat transfer equations for piping, being the stresses calculated according to ASME III NB-3600. (b) Thermal and stress analyses using axisymmetric elements, according to the rules presented at ASME III NB-3200. In the first case, named simplified analysis, the computer code used is the PIPESTRESS, while in the second case, the ANSYS program was adopted

The impacts of cooling construction on the ability distract the heat of condensation part of the heat pipe

Directory of Open Access Journals (Sweden)

Gavlas S.

2013-04-01

Full Text Available Heat pipes as cooling devices have a high potential. Their power to affect a variety of factors – the vapour pressure, the amount of media work etc. Itis therefore necessary to verify the calculated parameters also practically. To determine the performance of transmitted heat pipe is the best calorimetric method. When it is out of the flow and the temperature difference the cooling part of the heat pipe determines its transmitted power. The contribution is focused on comparison of two types of coolers. The first type is looped capillary cooler for the condenser section. The small diameter capillary is secured high coolant turbulence and hence heat dissipation. The second type is non-contact cooling, where cooling fluid washes direct heat pipe wall.

Investigation of Freeze and Thaw Cycles of a Gas-Charged Heat Pipe

Science.gov (United States)

Ku, Jentung; Ottenstein, Laura; Krimchansky, Alexander

2012-01-01

The traditional constant conductance heat pipes (CCHPs) currently used on most spacecraft run the risk of bursting the pipe when the working fluid is frozen and later thawed. One method to avoid pipe bursting is to use a gas-charged heat pipe (GCHP) that can sustain repeated freeze/thaw cycles. The construction of the GCHP is similar to that of the traditional CCHP except that a small amount of non-condensable gas (NCG) is introduced and a small length is added to the CCHP condenser to serve as the NCG reservoir. During the normal operation, the NCG is mostly confined to the reservoir, and the GCHP functions as a passive variable conductance heat pipe (VCHP). When the liquid begins to freeze in the condenser section, the NCG will expand to fill the central core of the heat pipe, and ice will be formed only in the grooves located on the inner surface of the heat pipe in a controlled fashion. The ice will not bridge the diameter of the heat pipe, thus avoiding the risk of pipe bursting during freeze/thaw cycles. A GCHP using ammonia as the working fluid was fabricated and then tested inside a thermal vacuum chamber. The GCHP demonstrated a heat transport capability of more than 200W at 298K as designed. Twenty-seven freeze/thaw cycles were conducted under various conditions where the evaporator temperature ranged from 163K to 253K and the condenser/reservoir temperatures ranged from 123K to 173K. In all tests, the GCHP restarted without any problem with heat loads between 10W and 100W. No performance degradation was noticed after 27 freeze/thaw cycles. The ability of the GCHP to sustain repeated freeze/thaw cycles was thus successfully demonstrated.

HPFRCC - Extruded Pipes

DEFF Research Database (Denmark)

Stang, Henrik; Pedersen, Carsten

1996-01-01

The present paper gives an overview of the research onHigh Performance Fiber Reinforced Cementitious Composite -- HPFRCC --pipes recently carried out at Department of Structural Engineering, Technical University of Denmark. The project combines material development, processing technique development......-w$ relationship is presented. Structural development involved definition of a new type of semi-flexiblecement based pipe, i.e. a cement based pipe characterized by the fact that the soil-pipe interaction related to pipe deformation is an importantcontribution to the in-situ load carrying capacity of the pipe...

Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki [and others

1997-04-01

The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program.

Effect of dynamic monotonic and cyclic loading on fracture behavior for Japanese carbon steel pipe STS410

International Nuclear Information System (INIS)

Kinoshita, Kanji; Murayama, Kouichi; Ogata, Hiroyuki

1997-01-01

The fracture behavior for Japanese carbon steel pipe STS410 was examined under dynamic monotonic and cyclic loading through a research program of International Piping Integrity Research Group (EPIRG-2), in order to evaluate the strength of pipe during the seismic event The tensile test and the fracture toughness test were conducted for base metal and TIG weld metal. Three base metal pipe specimens, 1,500mm in length and 6-inch diameter sch.120, were employed for a quasi-static monotonic, a dynamic monotonic and a dynamic cyclic loading pipe fracture tests. One weld joint pipe specimen was also employed for a dynamic cyclic loading test In the dynamic cyclic loading test, the displacement was controlled as applying the fully reversed load (R=-1). The pipe specimens with a circumferential through-wall crack were subjected four point bending load at 300C in air. Japanese STS410 carbon steel pipe material was found to have high toughness under dynamic loading condition through the CT fracture toughness test. As the results of pipe fracture tests, the maximum moment to pipe fracture under dynamic monotonic and cyclic loading condition, could be estimated by plastic collapse criterion and the effect of dynamic monotonic loading and cyclic loading was a little on the maximum moment to pipe fracture of the STS410 carbon steel pipe. The STS410 carbon steel pipe seemed to be less sensitive to dynamic and cyclic loading effects than the A106Gr.B carbon steel pipe evaluated in IPIRG-1 program

Secondary Flow Phenomena in Rotating Radial Straight Pipes

OpenAIRE

Cheng, K. C.; Wang, Liqiu

1995-01-01

Flow visualization results for secondary flow phenomena near the exit of a rotating radial-axis straight pipe (length ࡁ = 82 cm, inside diameter d = 3.81 cm, ࡁ/d 21.52) are presented to study the stabilizing (relaminarization) and destabilizing (early transition from laminar to turbulent flow) effects of Coriolis forces for Reynolds numbers Re = 500 ∼ 4,500 and rotating speeds n = 0 ∼ 200 rpm. The flow visualization was realised by smoke injection method. The main features of the trans...

Application of BP neural network for LRAD-based alpha contamination monitoring inside pipes

International Nuclear Information System (INIS)

Wu Xuemei; Li Zhe; Zhang Jinzhao; Li Pingchuan; Su Jilong; Tuo Xianguo; Liu Mingzhe

2012-01-01

Factors of airspeed, flux, activity, source position, pipe length and pipe diameter affect nonlinearly source activity readout of the Long Range Alpha Detection (LRAD). In this paper, multiparameter influence experiment is carried out using variable-control method, aiming at studying relationships between the readout and each of the factors. The back propagation (BP) neural network model is established to overcome the nonlinear effects of the factors on the readout, with the readout and the multiparameters being the input, and the source activity being the output. Experiment data of 948 groups are used for BP neural network forecasting, with an average relative error of 3.4218×10 -4 . And in a 100-group test, an average relative error of 2.217×10 -2 is obtained. It shows that with this method source radioactivity in pipes can be simulated. (authors)

Pipe damping

International Nuclear Information System (INIS)

Ware, A.G.

1985-01-01

Studies are being conducted at the Idaho National Engineering Laboratory to determine whether an increase in the damping values used in seismic structural analyses of nuclear piping systems is justified. Increasing the allowable damping would allow fewer piping supports which could lead to safer, more reliable, and less costly piping systems. Test data from availble literature were examined to determine the important parameters contributing to piping system damping, and each was investigated in separate-effects tests. From the combined results a world pipe damping data bank was established and multiple regression analyses performed to assess the relative contributions of the various parameters. The program is being extended to determine damping applicable to higher frequency (33 to 100 Hz) fluid-induced loadings. The goals of the program are to establish a methodology for predicting piping system damping and to recommend revised guidelines for the damping values to be included in analyses

Pulsating Heat pipe Only for Space (PHOS): results of the REXUS 18 sounding rocket campaign

International Nuclear Information System (INIS)

Creatini, F; Guidi, G M; Belfi, F; Cicero, G; Fioriti, D; Di Prizio, D; Piacquadio, S; Becatti, G; Orlandini, G; Frigerio, A; Fontanesi, S; Nannipieri, P; Rognini, M; Morganti, N; Filippeschi, S; Di Marco, P; Fanucci, L; Baronti, F; Mameli, M; Manzoni, M

2015-01-01

Two Closed Loop Pulsating Heat Pipes (CLPHPs) are tested on board REXUS 18 sounding rocket in order to obtain data over a relatively long microgravity period (approximately 90 s). The CLPHPs are partially filled with FC-72 and have, respectively, an inner tube diameter larger (3 mm) and slightly smaller (1.6 mm) than the critical diameter evaluated in static Earth gravity conditions. On ground, the small diameter CLPHP effectively works as a Pulsating Heat Pipe (PHP): the characteristic slug and plug flow pattern forms inside the tube and the heat exchange is triggered by thermally driven self-sustained oscillations of the working fluid. On the other hand, the large diameter CLPHP works as a two- phase thermosyphon in vertical position and doesn't work in horizontal position: in this particular condition, the working fluid stratifies within the device as the surface tension force is no longer able to balance buoyancy. Then, the idea to test the CLPHPs in reduced gravity conditions: as the gravity reduces the buoyancy forces becomes less intense and it is possible to recreate the typical PHP flow pattern also for larger inner tube diameters. This allows to increase the heat transfer rate and, consequently, to decrease the overall thermal resistance. Even though it was not possible to experience low gravity conditions due to a failure in the yoyo de-spin system, the thermal response to the peculiar acceleration field (hyper-gravity) experienced on board are thoroughly described. (paper)

Common Ambient Assisted Living Home Platform for Seamless Care

DEFF Research Database (Denmark)

Wagner, Stefan Rahr; Stenner, Rene; Memon, Mukhtiar

The CareStore project is investigating the feasibility of creating an open and flexible infrastructure for facilitating seamless deployment of assisted living devices and applications on heterogeneous platforms. The Common Ambient Assisted Living Home Platform (CAALHP) is intended to be the main ...

Production of Seamless Superconducting Radio Frequency Cavities from Ultra-fine Grained Niobium, Phase II Final Report

Energy Technology Data Exchange (ETDEWEB)

Roy Crooks, Ph.D., P.E.

2009-10-31

The positron and electron linacs of the International Linear Collider (ILC) will require over 14,000, nine-cell, one meter length, superconducting radio frequency (SRF) cavities [ILC Reference Design Report, 2007]. Manufacturing on this scale will benefit from more efficient fabrication methods. The current methods of fabricating SRF cavities involve deep drawing of the halves of each of the elliptical cells and joining them by high-vacuum, electron beam welding, with at least 19 circumferential welds per cavity. The welding is costly and has undesirable effects on the cavity surfaces, including grain-scale surface roughening at the weld seams. Hydroforming of seamless tubes avoids welding, but hydroforming of coarse-grained seamless tubes results in strain-induced surface roughening. Surface roughness limits accelerating fields, because asperities prematurely exceed the critical magnetic field and become normal conducting. This project explored the technical and economic feasibility of an improved processing method for seamless tubes for hydroforming. Severe deformation of bulk material was first used to produce a fine structure, followed by extrusion and flow-forming methods of tube making. Extrusion of the randomly oriented, fine-grained bulk material proceeded under largely steady-state conditions, and resulted in a uniform structure, which was found to be finer and more crystallographically random than standard (high purity) RRR niobium sheet metal. A 165 mm diameter billet of RRR grade niobium was processed into five, 150 mm I.D. tubes, each over 1.8 m in length, to meet the dimensions used by the DESY ILC hydroforming machine. Mechanical properties met specifications. Costs of prototype tube production were approximately twice the price of RRR niobium sheet, and are expected to be comparable with economies of scale. Hydroforming and superconducting testing will be pursued in subsequent collaborations with DESY and Fermilab. SRF Cavities are used to construct

Seamless user experiences in a brand new library

KAUST Repository

Vijayakumar, J.K.

2012-10-30

In order to provide seamless user experiences, the brand new libraries are far better positioned. They do not have to manage much in print, at least for the journal section, but huge electronic collection accessible via Internet. They do not worry about migrating to new systems or technology; they just start with whatever the latest available in the market, whether it is new generation ILMS, discovery tools, content management systems, mobile technologies, cloud computing etc. Patrons\\' expectations for seamless experience are met - regardless of their location, device and service they opted for. The story of the two and half years old, Saudi Arabia\\'s brand new King Abdullah University of Science and Technology\\'s Library is not different. Huge amount of electronic resources also provide ever increasing challenges to the new generation libraries in collecting, organizing and delivering the right information, to the right person at the right time. Implementation of a good ILMS supported with better electronic resource management features will help in setting the house right. Well-designed user interfaces, supported with the web scale discovery tools will help the users to have a better search experience. Availability of library collection through the campus mobile applications, latest proxy technologies for out-campus access and integrating the resources to the campus e-learning platform are the main features of the library’s seamless experiences. Libguide platform is used for the first time in Saudi Arabia, to create online research guides by subject librarians. An institutional repository, based on D-Space platform is about to release. Ninety percent of our collection is online; they are purchased, organized and accessed online, like any other brand new academic research libraries. Analysis of usage statistics of different resources show that they are highly used and usage is increased over two years, as the technology improved and implemented.

Evaluation of the efficiency and utility of recombinant enzyme-free seamless DNA cloning methods

Directory of Open Access Journals (Sweden)

Ken Motohashi

2017-03-01

Full Text Available Simple and low-cost recombinant enzyme-free seamless DNA cloning methods have recently become available. In vivo Escherichia coli cloning (iVEC can directly transform a mixture of insert and vector DNA fragments into E. coli, which are ligated by endogenous homologous recombination activity in the cells. Seamless ligation cloning extract (SLiCE cloning uses the endogenous recombination activity of E. coli cellular extracts in vitro to ligate insert and vector DNA fragments. An evaluation of the efficiency and utility of these methods is important in deciding the adoption of a seamless cloning method as a useful tool. In this study, both seamless cloning methods incorporated inserting DNA fragments into linearized DNA vectors through short (15–39 bp end homology regions. However, colony formation was 30–60-fold higher with SLiCE cloning in end homology regions between 15 and 29 bp than with the iVEC method using DH5α competent cells. E. coli AQ3625 strains, which harbor a sbcA gene mutation that activates the RecE homologous recombination pathway, can be used to efficiently ligate insert and vector DNA fragments with short-end homology regions in vivo. Using AQ3625 competent cells in the iVEC method improved the rate of colony formation, but the efficiency and accuracy of SLiCE cloning were still higher. In addition, the efficiency of seamless cloning methods depends on the intrinsic competency of E. coli cells. The competency of chemically competent AQ3625 cells was lower than that of competent DH5α cells, in all cases of chemically competent cell preparations using the three different methods. Moreover, SLiCE cloning permits the use of both homemade and commercially available competent cells because it can use general E. coli recA− strains such as DH5α as host cells for transformation. Therefore, between the two methods, SLiCE cloning provides both higher efficiency and better utility than the iVEC method for seamless DNA plasmid

Mitigation of inside surface residual stress of type 304 stainless steel pipe welds by inside water cooling method

International Nuclear Information System (INIS)

Sasaki, R.

1980-01-01

The weld residual stress distributions, macro- and microstructures of heat affected zone and IGSCC susceptibility of Type 304 stainless steel pipe welds by natural and inside water cooling methods have been investigated. The residual stresses of pipe welds by the natural cooling method are high tensile on both the inside and the outside surface. While the residual stresses on the inside surface of pipe welds by the inside water cooling method are compressive in both axial and circumferential directions for each pipe size from 2 to 24 inch diameter. The sensitized zones of welds by the inside water cooling method are closer to the fusion line, much narrower and milder than those by the natural cooling method. According to the constant extension rate test results for specimens taken from the inside surface of pipe welds, the inside water cooled welds are more resistant to IGSCC than naturally cooled ones

Numerical Analysis of Heat transfer Enhancement in a double pipe heat exchanger with a holed twisted tape

Directory of Open Access Journals (Sweden)

Kumar Akarsh

2018-01-01

Full Text Available In the present study numerical analysis of enhancement in heat transfer characteristics in a double pipe heat exchanger is studied using a holed twisted tape.The twisted tape with a constant twist ratio is inserted in a double pipe heat exchanger. Holes of diameter 1mm, 3 mm and 5 mm were drilled at regular pitch throughout the length of the tape. Numerical modeling of a double pipe heat exchanger with the holed twisted tape was constructed considering hot fluid flowing in the inner pipe and cold fluid through the annulus.Simulation was done for varied mass flow rates of hot fluid in the turbulent condition keeping the mass flow rate of cold fluid being constant. Thermal properties like Outlet temperatures, Nusselt number, overall heat transfer coefficient, heat transfer rate and pressure drop were determined for all the cases. Results indicated that normaltwisted tape without holes performed better than the bare tube. In the tested range of mass flow rates the average Nusselt number and heat transfer rate were increased by 85% and 34% respectively. Performance of Twisted tape with holes was slightly reduced than the normal twisted tape and it deteriorated further for higher values hole diameter. Pressure drop was found to be higher for the holed twisted tape than the normal tape.

Seamless Image Mosaicking via Synchronization

Science.gov (United States)

Santellani, E.; Maset, E.; Fusiello, A.

2018-05-01

This paper proposes an innovative method to create high-quality seamless planar mosaics. The developed pipeline ensures good robustness against many common mosaicking problems (e.g., misalignments, colour distortion, moving objects, parallax) and differs from other works in the literature because a global approach, known as synchronization, is used for image registration and colour correction. To better conceal the mosaic seamlines, images are cut along specific paths, computed using a Voronoi decomposition of the mosaic area and a shortest path algorithm. Results obtained on challenging real datasets show that the colour correction mitigates significantly the colour variations between the original images and the seams on the final mosaic are not evident.

PERFORMANCE EVALUATION OF AN INNOVATIVE FIBER REINFORCED GEOPOLYMER SPRAY-APPLIED MORTAR FOR LARGE DIAMETER WASTEWATER MAIN REHABILITATION IN HOUSTON, TX

Science.gov (United States)

This report describes the performance evaluation of a fiber reinforced geopolymer spray-applied mortar, which has potential as a structural alternative to traditional open cut techniques used in large-diameter sewer pipes. Geopolymer is a sustainable green material that incorpor...

Bayesian Belief Networks for predicting drinking water distribution system pipe breaks

International Nuclear Information System (INIS)

Francis, Royce A.; Guikema, Seth D.; Henneman, Lucas

2014-01-01

In this paper, we use Bayesian Belief Networks (BBNs) to construct a knowledge model for pipe breaks in a water zone. To the authors’ knowledge, this is the first attempt to model drinking water distribution system pipe breaks using BBNs. Development of expert systems such as BBNs for analyzing drinking water distribution system data is not only important for pipe break prediction, but is also a first step in preventing water loss and water quality deterioration through the application of machine learning techniques to facilitate data-based distribution system monitoring and asset management. Due to the difficulties in collecting, preparing, and managing drinking water distribution system data, most pipe break models can be classified as “statistical–physical” or “hypothesis-generating.” We develop the BBN with the hope of contributing to the “hypothesis-generating” class of models, while demonstrating the possibility that BBNs might also be used as “statistical–physical” models. Our model is learned from pipe breaks and covariate data from a mid-Atlantic United States (U.S.) drinking water distribution system network. BBN models are learned using a constraint-based method, a score-based method, and a hybrid method. Model evaluation is based on log-likelihood scoring. Sensitivity analysis using mutual information criterion is also reported. While our results indicate general agreement with prior results reported in pipe break modeling studies, they also suggest that it may be difficult to select among model alternatives. This model uncertainty may mean that more research is needed for understanding whether additional pipe break risk factors beyond age, break history, pipe material, and pipe diameter might be important for asset management planning. - Highlights: • We show Bayesian Networks for predictive and diagnostic management of water distribution systems. • Our model may enable system operators and managers to prioritize system

Pipe connector

International Nuclear Information System (INIS)

Sullivan, T.E.; Pardini, J.A.

1978-01-01

A safety test facility for testing sodium-cooled nuclear reactor components includes a reactor vessel and a heat exchanger submerged in sodium in the tank. The reactor vessel and heat exchanger are connected by an expansion/deflection pipe coupling comprising a pair of coaxially and slidably engaged tubular elements having radially enlarged opposed end portions of which at least a part is of spherical contour adapted to engage conical sockets in the ends of pipes leading out of the reactor vessel and in to the heat exchanger. A spring surrounding the pipe coupling urges the end portions apart and into engagement with the spherical sockets. Since the pipe coupling is submerged in liquid a limited amount of leakage of sodium from the pipe can be tolerated

Physical Modelling of Large Diameter Piles in Coarse-Grained Soil

DEFF Research Database (Denmark)

Brødbæk, K. T.; Augustesen, Anders Hust; Møller, M.

2011-01-01

of increasing the effective stresses. The test setup is thoroughly described in the paper. Two non-slender aluminium pipe piles subjected to lateral loads have been tested in the laboratory. The piles are heavily instrumented with strain gauges in order to obtain p-y curves, displacement and bending moment......Monopiles are an often-used foundation concept for offshore wind turbine converters. These piles are highly subjected to lateral loads and overturning bending moments due to wind and wave forces. To ensure enough stiffness of the foundation and an acceptable pile-head deflection, monopiles...... with diameters of 4 to 6 m are typically employed. In current practice these piles are traditionally designed by means of the p-y curve method although the method is developed and verified for slender piles in sand with diameters up to approximately 2 m. One of the limitations of the p-y curves used in current...

Experimental Study on Pipe Sections against Impact Loading

Directory of Open Access Journals (Sweden)

Engin GÜCÜYEN

2018-02-01

Full Text Available Pipelines are significant structural systems that transfer necessary materials from one place to another. They are under the effect of static and dynamic loads during their service lives. Investigations have become important to determine the effects of sudden dynamic loads with technological developments. Researchers study the mechanical properties of different materials and structural members under dynamic effects such as earthquake, wind, blast, rock falling and vehicle crushing. For this purpose, different test setups have been developed to investigate the behaviour of test members. In this study, galvanized and water filled galvanized pipe sections having three different diameter values are produced in a laboratory to perform tests under impact loading. The behaviour of the pipes is determined by free falling test apparatus. In addition, measurement devices as accelerometer, dynamic force sensor, lvdt, and data logger are used in the experimental program. So, acceleration, impact force, and displacement values are obtained during the tests. Besides, damage developments of the pipes are also observed to determine the impact resistances of test members. The results are compared to each other and it is stated that while acceleration and impact force values decrease, displacement values increase as the test members approach to collapse damage situation.

Transient thermal performance analysis of micro heat pipes

International Nuclear Information System (INIS)

Liu, Xiangdong; Chen, Yongping

2013-01-01

A theoretical analysis of transient fluid flow and heat transfer in a triangular micro heat pipes (MHP) has been conducted to study the thermal response characteristics. By introducing the system identification theory, the quantitative evaluation of the MHP's transient thermal performance is realized. The results indicate that the evaporation and condensation processes are both extended into the adiabatic section. During the start-up process, the capillary radius along axial direction of MHP decreases drastically while the liquid velocity increases quickly at the early transient stage and an approximately linear decrease in wall temperature arises along the axial direction. The MHP behaves as a first-order LTI control system with the constant input power as the 'step input' and the evaporator wall temperature as the 'output'. Two corresponding evaluation criteria derived from the control theory, time constant and temperature constant, are able to quantitatively evaluate the thermal response speed and temperature level of MHP under start-up, which show that a larger triangular groove's hydraulic diameter within 0.18–0.42 mm is able to accelerate the start-up and decrease the start-up temperature level of MHP. Additionally, the MHP starts up fastest using the fluid of ethanol and most slowly using the working fluid of methanol, and the start-up temperature reaches maximum level for acetone and minimum level for the methanol. -- Highlights: • Transient thermal response of micro heat pipe is simulated by an improved model. • Control theory is introduced to quantify the thermal response of micro heat pipe. • Evaluation criteria are proposed to represent thermal response of micro heat pipe. • Effects of groove dimensions and working fluids on start-up of micro heat pipe are evaluated

Reactor process water (PW) piping inspections, 1984--1990

International Nuclear Information System (INIS)

Ehrhart, W.S.; Elder, J.B.; Sprayberry, R.E.; Vande Kamp, R.W.

1990-01-01

In July 1983, the NRC ordered the shutdown of five boiling water reactors (BWR's) because of concerns about reliability of ultrasonic examination for detecting intergranular stress corrosion cracking (IGSCC). These concerns arose because of leaking piping at Niagara Mohawk's Nine Mile Point which was attributed to IGSCC. The leaks were detected shortly after completion of ultrasonic examinations of the piping. At that time, the Dupont plant manager at Savannah River (SR) directed that investigations be performed to determine if similar problems could exist in SR reactors. Investigation determined that all conditions believed necessary for the initiation and propagation of IGSCC in austenitic stainless steel exist in SR reactor process water (PW) systems. Sensitized, high carbon, austenitic stainless steel, a high purity water system with high levels of dissolved oxygen, and the residual stresses associated with welding during construction combine to provide the necessary conditions. A periodic UT inspection program is now in place to monitor the condition of the reactor PW piping systems. The program is patterned after NRC NUREG 0313, i.e., welds are placed in categories based on their history. Welds in upgraded or replacement piping are examined on a standard schedule (at least every five years) while welds with evidence of IGSCC, evaluated as acceptable for service, are inspected at every extended outage (15 to 18 months). This includes all welds in PW systems three inches in diameter and above. Welds are replaced when MSCC exceeds the replacement criteria of more than twenty percent of pipe circumference of fifty percent of through-wall depth. In the future, we intend to perform flow sizing with automated UT techniques in addition to manual sizing to provide more information for comparison with future examinations

Behavior of water jet horizontally discharged from a small circular hole set on a circular pipe-surface into air

International Nuclear Information System (INIS)

Tsuyuki, Koji; Igarashi, Saburo; Sudo, Seiichi; Yamabe, Masahiro; Kikuchi, Akira; Oba, Risaburo

2001-01-01

In order to clarify the behavior of the water jet horizontally discharged from a small circular hole set on a circular pipe surface into air, in this paper, for the first step, we systematically observed the jet aspects, the efflux angle, the discharge coefficient and so on, when the hole diameter d is much smaller than the pipe diameter D. Since the upstream kinetic energy from the hole is somewhat higher than the downstream counterpart, the upstream partial jet with higher efflux angle crashes into the downstream partial jet and drives out the latter into up- and down-side, resulting in a marked pair of vortices, so that resulting in a three-dimensional spiral flow accompanying with marked surface waves. (author)

Failure Analysis of PRDS Pipe in a Thermal Power Plant Boiler

Science.gov (United States)

Ghosh, Debashis; Ray, Subrata; Mandal, Jiten; Mandal, Nilrudra; Shukla, Awdhesh Kumar

2018-04-01

The pressure reducer desuperheater (PRDS) pipeline is used for reducing the pressure and desuperheating of the steam in different auxiliary pipeline. When the PRDS pipeline is failed, the reliability of the boiler is affected. This paper investigates the probable cause/causes of failure of the PRDS tapping line. In that context, visual inspection, outside diameter and wall thickness measurement, chemical analysis, metallographic examination and hardness measurement are conducted as part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it has been concluded that the PRDS pipeline has mainly failed due to graphitization due to prolonged exposure of the pipe at higher temperature. The improper material used is mainly responsible for premature failure of the pipe.

1998 Annual Study Report. Standardization of methods for evaluating characteristics of high-strength, large-diameter steel pipes for superhigh-pressure natural gas pipelines; 1998 nendo seika hokokusho. Chokoatsu tennen gas pipeline yo kokyodo daikei kokan no tokusei hoho no hyojunka

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The pipelines for safely transmitting superhigh-pressure natural gas should have excellent characteristics. The steel pipe is required to have a sufficient toughness, more concretely Charpy impact-absorbing energy, to prevent propagating shear fracture characteristic of natural gas pipelines. Recently, the natural gas pipeline is increasingly required to have higher design pressures (15 Mpa or higher) and grade (X80 or higher). In order to develop the techniques for simulating crack propagation in the propagating shear fracture of natural gas pipe lines as part of the programs to cope with these trends, the 1998 efforts were directed to reviewing the research results obtained so far and analysis of the problems to be solved and tasks to be taken, based on which the analytical procedure for gas releasing phenomena during the fracture process was basically developed, the material characteristic data were collected by the laboratory scale toughness tests, and the preliminary tests with rupture disks were conducted to verify the above analytical procedure. These efforts have established the bases for evaluating the characteristics of high-strength, large-diameter steel pipes in the light of safety against fracture, and greatly advanced the program towards the final target of developing the international specification drafts for toughness. (NEDO)

Metallurgical failure investigation of a pipe connector fracture of an expansion vessel

International Nuclear Information System (INIS)

Neidel, Andreas

2016-01-01

A pipe connector of an expansion vessel of a safety heat exchanger was torn off in a test facility's natural gas compressor. From a material point of view, the cause of the damage is a fatigue fracture induced by pulsating bending stress. The fatigue fracture originated from both, the pipe's outer surface as well as from its inner surface, which is consistent with the given stress situation (pulsating bending stress). Material defects or welding-induced flaws were not observed. Corrosion, wear, or thermal overload which may have promoted the damage, were not observed either. The primary cause was a major design error. Cases of dynamic load were obviously not duly taken into account during designing, so that the free-swinging mass of the expansion vessel which was mounted to a pipe of a diameter of only half an inch and, furthermore, installed in an angle of 45 (additional static preload.), could cause the fatigue failure induced by pulsating bending stress in the zone of highest stresses at the transition of the expansion vessel and the the pipe connector due to dynamic operating loads which always occur in plants like these.

Application of failure assessment diagram methods to cracked straight pipes and elbows

International Nuclear Information System (INIS)

Ainsworth, R.A.; Gintalas, M.; Sahu, M.K.; Chattopadhyay, J.; Dutta, B.K.

2016-01-01

This paper reports fracture assessments of large-scale straight pipes and elbows of various pipe diameters and crack sizes. The assessments estimate the load for ductile fracture initiation using the failure assessment diagram method. Recent solutions in the literature for stress intensity factor and limit load provide the analysis inputs. An assessment of constraint effects is also performed using recent solutions for elastic T-stress. It is found that predictions of initiation load are close to the experimental values for straight pipes under pure bending. For elbows, there is generally increased conservatism in the sense that the experimental loads are greater than those predicted. The effects of constraint are found not to be a major contributor to the initiation fracture assessments but may have some influence on the ductile crack extension. - Highlights: • This paper presents assessments of the loads for ductile fracture initiation in 21 large-scale piping tests. • Modern stress intensity factor and limit load solutions were used for standard failure assessment diagram methods. • This leads to generally accurate assessments of the loads for ductile crack initiation. • The effects of constraint are found not to be a major contributor to the initiation fracture assessments.

Seamless Language Learning: Second Language Learning with Social Media

Science.gov (United States)

Wong, Lung-Hsiang; Chai, Ching Sing; Aw, Guat Poh

2017-01-01

This conceptual paper describes a language learning model that applies social media to foster contextualized and connected language learning in communities. The model emphasizes weaving together different forms of language learning activities that take place in different learning contexts to achieve seamless language learning. it promotes social…

Distance tracking scheme for seamless handover in IMS-based ...

African Journals Online (AJOL)

This paper proposes a fast and seamless handover scheme for systems based on IP Multimedia Subsystem (IMS) architectural framework with Universal Mobile Telecommunications System (UMTS) access network. In the scheme the location, direction and movement pattern of a Mobile Node (MN) in a network cell are ...

Laminar Mixed Convection Heat Transfer Correlation for Horizontal Pipes

International Nuclear Information System (INIS)

Chae, Myeong Seon; Chung, Bum Jin

2013-01-01

This study aimed at producing experimental results and developing a new heat transfer correlation based upon a semi-empirical buoyancy coefficient. Mixed convection mass transfers inside horizontal pipe were investigated for the pipe of various length-to-diameters with varying Re. Forced convection correlation was developed using a very short cathode. With the length of cathode increase and Re decrease, the heat transfer rates were enhanced and becomes higher than that of forced convection. An empirical buoyancy coefficient was derived from correlation of natural convection and forced convection with the addition of L/D. And the heat transfer correlation for laminar mixed convection was developed using the buoyancy coefficient, it describes not only current results, but also results of other studies. Mixed convection occurs when the driving forces of both forced and natural convections are of comparable magnitude (Gr/Re 2 ∼1). It is classical problem but is still an active area of research for various thermal applications such as flat plate solar collectors, nuclear reactors and heat exchangers. The effect of buoyancy on heat transfer in a forced flow is varied by the direction of the buoyancy force. In a horizontal pipe the direction of the forced and buoyancy forces are perpendicular. The studies on the mixed convections of the horizontal pipes were not investigated very much due to the lack of practical uses compared to those of vertical pipes. Even the definitions on the buoyancy coefficient that presents the relative influence of the forced and the natural convections, are different by scholars. And the proposed heat transfer correlations do not agree

Crack stability in a representative piping system under combined inertial and seismic/dynamic displacement-controlled stresses. Subtask 1.3 final report

International Nuclear Information System (INIS)

Scott, P.; Olson, R.; Wilkowski, O.G.; Marschall, C.; Schmidt, R.

1997-06-01

This report presents the results from Subtask 1.3 of the International Piping Integrity Research Group (IPIRG) program. The objective of Subtask 1.3 is to develop data to assess analysis methodologies for characterizing the fracture behavior of circumferentially cracked pipe in a representative piping system under combined inertial and displacement-controlled stresses. A unique experimental facility was designed and constructed. The piping system evaluated is an expansion loop with over 30 meters of 16-inch diameter Schedule 100 pipe. The experimental facility is equipped with special hardware to ensure system boundary conditions could be appropriately modeled. The test matrix involved one uncracked and five cracked dynamic pipe-system experiments. The uncracked experiment was conducted to evaluate piping system damping and natural frequency characteristics. The cracked-pipe experiments evaluated the fracture behavior, pipe system response, and stability characteristics of five different materials. All cracked-pipe experiments were conducted at PWR conditions. Material characterization efforts provided tensile and fracture toughness properties of the different pipe materials at various strain rates and temperatures. Results from all pipe-system experiments and material characterization efforts are presented. Results of fracture mechanics analyses, dynamic finite element stress analyses, and stability analyses are presented and compared with experimental results

Crack stability in a representative piping system under combined inertial and seismic/dynamic displacement-controlled stresses. Subtask 1.3 final report

Energy Technology Data Exchange (ETDEWEB)

Scott, P.; Olson, R.; Wilkowski, O.G.; Marschall, C.; Schmidt, R.

1997-06-01

This report presents the results from Subtask 1.3 of the International Piping Integrity Research Group (IPIRG) program. The objective of Subtask 1.3 is to develop data to assess analysis methodologies for characterizing the fracture behavior of circumferentially cracked pipe in a representative piping system under combined inertial and displacement-controlled stresses. A unique experimental facility was designed and constructed. The piping system evaluated is an expansion loop with over 30 meters of 16-inch diameter Schedule 100 pipe. The experimental facility is equipped with special hardware to ensure system boundary conditions could be appropriately modeled. The test matrix involved one uncracked and five cracked dynamic pipe-system experiments. The uncracked experiment was conducted to evaluate piping system damping and natural frequency characteristics. The cracked-pipe experiments evaluated the fracture behavior, pipe system response, and stability characteristics of five different materials. All cracked-pipe experiments were conducted at PWR conditions. Material characterization efforts provided tensile and fracture toughness properties of the different pipe materials at various strain rates and temperatures. Results from all pipe-system experiments and material characterization efforts are presented. Results of fracture mechanics analyses, dynamic finite element stress analyses, and stability analyses are presented and compared with experimental results.