Sample records for welded x70 pipeline

  1. Anodic Dissolution of API X70 Pipeline Steel in Arabian Gulf Seawater after Different Exposure Intervals


    El-Sayed M. Sherif; Abdulhakim A. Almajid


    The anodic dissolution of API X70 pipeline steel in Arabian Gulf seawater (AGSW) was investigated using open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), cyclic potentiodynamic polarization (CPP), and current-time measurements. The electrochemical experiments revealed that the X70 pipeline steel suffers both general and pitting corrosion in the AGSW solution. It was found that the general corrosion decreases as a result of decreasing the corrosion current density (jc...

  2. Determination of acoustoelastic constant in API-5L-X70 welded pipes; Determinacao da constante acustoelastica de tubos API-5L-X70 com solda

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    Bittencourt, Marcelo de Siqueira Queiroz; Fonseca, Manoel Antonio da Costa [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Oliveira, Carlos Henrique Francisco de [PETROBRAS S.A., Rio de de Janeiro, RJ (Brazil)


    To preserve the environment and avoid financial losses resulting from leaks in the transport of natural oil and gas the industry is particularly concerned to ensure the structural integrity of their pipelines. Grounded pipes may be exposed to damages due to unstable soil movement, and in extreme cases, to failure. Then, techniques to assess stress in pipelines are of central importance. The ultrasonic birefringence technique is an efficient method to measure residual stress. It is based on the changing velocity of the shear wave when it crosses a material under stress; this phenomenon is known as acoustoelasticity. The knowledge of the parameter called acoustoelastic constant is necessary to measure stress using this technique. By the mechanical conformation in the manufacture of welded tubes, from rolled plates, different anisotropy degrees are showed around the cross section of these tubes. In this paper it was studied the acoustoelastic constant for the API-5L-X70 steel pipes, with different thicknesses, diameters and manufacturing processes so as to be able to use this technique to stress measurement in pipelines. (author)

  3. Slow strain rate corrosion and fracture characteristics of X-52 and X-70 pipeline steels

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    Contreras, A. [Instituto Mexicano del Petroleo, Programa de Investigacion y Desarrollo de Ductos, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, C.P. 07730, Mexico, D.F. (Mexico)]. E-mail:; Albiter, A. [Instituto Mexicano del Petroleo, Programa de Investigacion y Desarrollo de Ductos, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, C.P. 07730, Mexico, D.F. (Mexico); Salazar, M. [Instituto Mexicano del Petroleo, Programa de Investigacion y Desarrollo de Ductos, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, C.P. 07730, Mexico, D.F. (Mexico); Perez, R. [Instituto Mexicano del Petroleo, Programa de Investigacion y Desarrollo de Ductos, Eje Central Lazaro Cardenas 152, San Bartolo Atepehuacan, C.P. 07730, Mexico, D.F. (Mexico)


    The susceptibility to stress corrosion cracking (SCC) in a NACE solution saturated with H{sub 2}S, of the X-52 and X-70 steels was studied using slow strain rate tests (SSRT) and electrochemical evaluations. SCC tests were performed in samples which include the longitudinal weld bead of the pipeline steels and were carried out in the NACE solution at both room temperature and 50 deg. C. After failure, the fracture surfaces were observed in a scanning electron microscope (SEM) and the chemical analysis were obtained using X-rays energy dispersive (EDXs) techniques. The specimens tested in air, exhibited a ductile type of failure, and whereas, those tested in the corrosive solution showed a brittle fracture. Specimens tested in the NACE solution saturated with H{sub 2}S presented high susceptibility to SCC. Corrosion was found to be an important factor in the initiation of some cracks. In addition, the effect of the temperature on the corrosion attack was explored. The susceptibility to SCC was manifested as a decrease in the mechanical properties. Potentiodynamic polarization curves and hydrogen permeation measurements were made. The diffusion of atomic hydrogen was related to this fracture forms. The hydrogen permeation flux increased with the increasing of temperature.

  4. Anodic Dissolution of API X70 Pipeline Steel in Arabian Gulf Seawater after Different Exposure Intervals

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    El-Sayed M. Sherif


    Full Text Available The anodic dissolution of API X70 pipeline steel in Arabian Gulf seawater (AGSW was investigated using open-circuit potential (OCP, electrochemical impedance spectroscopy (EIS, cyclic potentiodynamic polarization (CPP, and current-time measurements. The electrochemical experiments revealed that the X70 pipeline steel suffers both general and pitting corrosion in the AGSW solution. It was found that the general corrosion decreases as a result of decreasing the corrosion current density (jcorr, corrosion rate (Rcorr and absolute currents as well as the increase of polarization resistance of X70 with increasing the exposure time. On the other hand, the pitting corrosion was found to increase with increasing the immersion time. This was confirmed by the increase of current with time and by the SEM images that were obtained on the steel surface after 20 h immersion before applying an amount of 0–.35 V versus Ag/AgCl for 1 h.

  5. Study of sulphate-reducing bacteria corrosion in the weld joint for API X-70 steel

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    Flores, J. E.; Patino-Carachure, C.; Alfonso, I.; Rodriguez, J. A.; Rosas, G.


    The corrosion behavior originated by sulfate-reducing bacteria (SRB) was studied in two regions of welded API X-70 steel pipeline. The studies were focused on base material (BM) and heat affected zone (HAZ), from the internal region of the pipe. SRB were extracted from oil and grown in a Postgate medium. Corrosion was evaluated at 60 degree centigrade for times between 5 and 64 days. Potentiodynamic polarization curves, obtained by electrochemical techniques, indicated surface activation at short times. Structural and morphological characterizations were carried out by scanning electron microscopy (SEM) and optical microscopy (OM). H{sub 2}S concentration and pH were also measured. Results showed an important increase in the corrosion damage up to 20 days, influenced by the SRB activity, which lead to a maximum of H{sub 2}S (pH minimum). It was found a localized corrosion attack in the HAZ in a higher quantity compared to BM; and the formation of a thin film on the steel surface, originated by corrosion products and bacterial activity. (Author) 15 refs.

  6. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

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    Shengrong Wang


    Full Text Available The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM,energy dispersive X-ray spectroscopy (EDS, and X-ray diffraction (XRD. The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface. α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS are consistent with potentiodynamic polarization tests.

  7. Effect of different microstructural parameters on hydrogen induced cracking in an API X70 pipeline steel (United States)

    Mohtadi-Bonab, M. A.; Eskandari, M.; Karimdadashi, R.; Szpunar, J. A.


    In this study, the surface and cross section of an as-received API X70 pipeline steel was studied by SEM and EDS techniques in order to categorize the shape and morphology of inclusions. Then, an electrochemical hydrogen charging using a mixed solution of 0.2 M sulfuric acid and 3 g/l ammonium thiocyanate has been utilized to create hydrogen cracks in X70 steel. After hydrogen charging experiments, the cross section of this steel has been accurately checked by SEM in order to find out hydrogen cracks. The region of hydrogen cracks was investigated by SEM and EBSD techniques to predict the role of different microstructural parameters involving hydrogen induced cracking (HIC) phenomenon. The results showed that inclusions were randomly distributed in the cross section of tested specimens. Moreover, different types of inclusions in as-received X70 steel were found. However, only inclusions which were hard, brittle and incoherent with the metal matrix, such as manganese sulfide and carbonitride precipitates, were recognized to be harmful to HIC phenomenon. Moreover, HIC cracks propagate dominantly in transgraular manner through differently oriented grains with no clear preferential trend. Moreover, a different type of HIC crack with about 15-20 degrees of deviation from the rolling direction was found and studied by EBSD technique and role of micro-texture parameters on HIC was discussed.

  8. Study of sulphate-reducing bacteria corrosion in the weld joint for API X-70 steel

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    Flores, J. E.


    Full Text Available The corrosion behavior originated by sulfate-reducing bacteria (SRB was studied in two regions of welded API X-70 steel pipeline. The studies were focused on base material (BM and heat affected zone (HAZ, from the internal region of the pipe. SRB were extracted from oil and grown in a Postgate medium. Corrosion was evaluated at 60 °C for times between 5 and 64 days. Potentiodynamic polarization curves, obtained by electrochemical techniques, indicated surface activation at short times. Structural and morphological characterizations were carried out by scanning electron microscopy (SEM and optical microscopy (OM. H2S concentration and pH were also measured. Results showed an important increase in the corrosion damage up to 20 days, influenced by the SRB activity, which lead to a maximum of H2S (pH minimum. It was found a localized corrosion attack in the HAZ in a higher quantity compared to BM; and the formation of a thin film on the steel surface, originated by corrosion products and bacterial activity.

    El comportamiento ante la corrosión, originada por bacterias sulfato-reductoras (SRB, fue estudiado en dos regiones de un tubo de acero soldado API X-70. Los estudios se enfocaron en el material base (BM y la zona afectada térmicamente (HAZ, en la parte interna del tubo. Las SRB fueron extraídas del petróleo y cultivadas en un medio Postgate. El comportamiento a la corrosión fue evaluado a una temperatura de 60 °C, por periodos comprendidos entre 5 y 64 días. El análisis de las curvas de polarización potenciodinámicas, obtenidas por técnicas electroquímicas, indicó la activación de la superficie para tiempos cortos. La superficie fue caracterizada estructural y morfológicamente mediante microscopia electrónica de barrido (SEM, así como mediante microscopía óptica (OM. La concentración de H2S y el pH también fueron medidos. Los resultados mostraron un aumento importante de la corrosi

  9. Influence of crystallographic texture in X70 pipeline steels on toughness anisotropy and delamination (United States)

    Al-Jabr, Haytham M.

    The effects of microstructure and crystallographic texture in four commercially-produced API X70 pipeline steels and their relation to planar anisotropy of toughness and delamination were evaluated. The experimental steels were processed through either a hot strip mill, a Steckel mill, or a compact strip mill. Different processing routes were selected to obtain plates with potential variations in the microstructure and anisotropic characteristics. Tensile and Charpy impact testing were used to evaluate the mechanical properties in three orientations: longitudinal (L), transverse (T) and diagonal (D) with respect to the rolling direction to evaluate mechanical property anisotropy. The yield and tensile strengths were higher in the T orientation and toughness was lower in the D orientation for all plates. Delamination was observed in some of the ductile fracture surfaces of the impact samples. To further study the splitting behavior and effects on impact toughness, a modified impact test (MCVN) specimen with side grooves was designed to intensify induced stresses parallel to the notch root and thus facilitate evaluation of delamination. Scanning electron microscopy combined with electron backscattered diffraction (EBSD) were used to evaluate the grain size, microstructural constituents, and crystallographic texture to determine the factors leading to delamination and the anisotropy in toughness. The ferrite grain size is mainly responsible for the differences in DBTTs between the L and T orientations. The higher DBTT in the D orientation observed in pipeline steels is attributed to crystallographic texture. The higher DBTT in the D direction is due to the higher volume fraction of grains having their {100} planes parallel or close to the primary fracture plane for the D orientation. An equation based on a new "brittleness parameter," based on an assessment of grain orientations based on EBSD data, was developed to predict the changes in DBTTs with respect to sample

  10. Pitting Initiation and Propagation of X70 Pipeline Steel Exposed to Chloride-Containing Environments

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    Zixuan Yang


    Full Text Available Inclusion-induced pitting initiation mechanisms in X70 steel were investigated by scanning electron microscopy, scanning Kelvin probe force microscopy (SKPFM, immersion and electrochemical polarization tests in chloride-containing ion solutions. There are three inclusion types in the X70 steel. Corrosion test results indicated that pitting corrosion resistance of type A inclusion < type C inclusion < type B inclusion, i.e., (Mn, CaS < matrix < (Al, CaO. SKPFM test results show that the type A inclusion exhibited both lower and higher potentials than the matrix, while the type B inclusion exhibited higher potential than the matrix. The corrosion test and the SKPFM potential test results are consistent. Potentiodynamic polarization results indicate that the type A and C are active inclusions, while the type B is an inactive inclusion. Three kinds of possible mechanisms of inclusion-induced pitting corrosion are established for the X70 steel.

  11. Characterization of HAZ of API X70 Microalloyed Steel Welded by Cold-Wire Tandem Submerged Arc Welding (United States)

    Mohammadijoo, Mohsen; Kenny, Stephen; Collins, Laurie; Henein, Hani; Ivey, Douglas G.


    High-strength low-carbon microalloyed steels may be adversely affected by the high-heat input and thermal cycle that they experience during tandem submerged arc welding. The heat-affected zone (HAZ), particularly the coarse-grained heat-affected zone (CGHAZ), i.e., the region adjacent to the fusion line, has been known to show lower fracture toughness compared with the rest of the steel. The deterioration in toughness of the CGHAZ is attributed to the formation of martensite-austenite (M-A) constituents, local brittle zones, and large prior austenite grains (PAG). In the present work, the influence of the addition of a cold wire at various wire feed rates in cold-wire tandem submerged arc welding, a recently developed welding process for pipeline manufacturing, on the microstructure and mechanical properties of the HAZ of a microalloyed steel has been studied. The cold wire moderates the heat input of welding by consuming the heat of the trail electrode. Macrostructural analysis showed a decrease in the CGHAZ size by addition of a cold wire. Microstructural evaluation, using both tint etching optical microscopy and scanning electron microscopy, indicated the formation of finer PAGs and less fraction of M-A constituents with refined morphology within the CGHAZ when the cold wire was fed at 25.4 cm/min. This resulted in an improvement in the HAZ impact fracture toughness. These improvements are attributed to lower actual heat introduced to the weldment and lower peak temperature in the CGHAZ by cold-wire addition. However, a faster feed rate of the cold wire at 76.2 cm/min adversely affected the toughness due to the formation of slender M-A constituents caused by the relatively faster cooling rate in the CGHAZ.

  12. Study of verification and validation of standard welding procedure specifications guidelines for API 5L X-70 grade line pipe welding

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    Qazi H. A. A.


    Full Text Available Verification and validation of welding procedure specifications for X-70 grade line pipe welding was performed as per clause 8.2, Annexure B and D of API 5L, 45th Edition to check weld integrity in its future application conditions. Hot rolled coils were imported from China, de-coiling, strip edge milling, three roller bending to from pipe, inside and outside submerged arc welding of pipe, online ultrasonic testing of weld, HAZ and pipe body, cutting at fixed random length of pipe, visual inspection of pipe, Fluoroscopic inspection of pipe, welding procedure qualification test pieces marking at weld portion of the pipe, tensile testing, guided bend testing, CVN Impact testing were performed. Detailed study was conducted to explore possible explanations and variation in mechanical properties, WPS is examined and qualified as per API 5L 45th Edition.

  13. Anodic Dissolution Behavior of the Crack Tip of X70 Pipeline Steel in Near-Neutral pH Environment (United States)

    Cui, Zhongyu; Wang, Liwei; Liu, Zhiyong; Du, Cuiwei; Li, Xiaogang; Wang, Xin


    In this work, the anodic dissolution behavior of the fresh metal surface at crack tip of X70 steel in near-neutral pH environment was investigated using galvanic corrosion simulation method. The solution environment, strain, strain rate, hydrogen enrichment, and fresh metal surface at the crack tip were considered. Corrosion current of the specimen during fast stretching increased linearly with plastic strain. The increment and increase rate of the corrosion current during plastic deformation stage were dependent on the strain rate. Combining Faraday's law and crack tip strain rate equation, the crack growth rate (CGR) induced by the anodic dissolution of the fresh metal surface was calculated. Results show that CGR caused by anodic dissolution was roughly one order lower than that measured on the compact tensile specimen under cyclic load. This finding indicated that hydrogen embrittlement may play a dominate role in stress corrosion crack propagation of pipeline steels in near-neutral pH environment.

  14. A study of processes for welding pipelines

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    Weston, J. (ed.)


    A review was made of exisiting and potential processes for welding pipelines: fusion welding (arc, electron beam, laser, thermit) and forge welding (friction, flash, magnetically impelled arc butt, upset butt, explosive, shielded active gas, gas pressure). Consideration of J-lay operations gave indications that were reflections of the status of the processes in terms of normal land and offshore S-lay operation: forge welding processes, although having promise require considerable development; fusion welding processes offer several possibilities (mechanized GMA welding likely to be used in 1991-2); laser welding requires development in all pipeline areas: a production machine for electron beam welding will involve high costs. Nondestructive testing techniques are also reviewed. Demand for faster quality assessment is being addressed by speeding radiographic film processing and through the development of real time radiography and automatic ultrasonic testing. Conclusions on most likely future process developments are: SMAW with cellulosic electrodes is best for tie-ins, short pip runs; SMAW continues to be important for small-diameter lines, although mechanized GMA could be used, along with mechanical joining, MIAB, radial fraction, and flash butt; mechanized GMA welding is likely to predominate for large diameter lines and probably will be used for the first J-lay line (other techniques could be used too); and welding of piping for station facilities involves both shop welding of sub-assemblies and on-site welding of pipe and sub-assemblies to each other (site welding uses both SMAW and GMAW). Figs, tabs.

  15. The effect of processing parameters on the dynamic recrystallisation behaviour of API-X70 pipeline steel

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    Al Shahrani, Abdullah, E-mail: [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Yazdipour, Nima; Dehghan-Manshadi, Ali [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Gazder, Azdiar A. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2519 (Australia); Cayron, Cyril [CEA, DRT, LITEN, Minatec, 38054 Grenoble Cedex 9 (France); Pereloma, Elena V. [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, New South Wales 2522 (Australia); Electron Microscopy Centre, University of Wollongong, New South Wales 2519 (Australia)


    The effect of deformation temperature and strain rate on the dynamic recrystallisation (DRX) behaviour of X70 pipeline steel was investigated. DRX parameters such as the critical and peak stresses and strains as well as the deformation activation energy were determined in the temperature range between 925 °C and 1125 °C for strain rates of 0.1, 1 and 5 s{sup −1}. The relationship between the peak stresses and strains with the Zener–Hollomon parameter was determined. The dynamically recrystallised volume fraction was computed as a function of the different temperatures and strain rates. The APRGE software was applied for the first time on electron back-scattering diffraction data of dynamically recrystallised microstructures in order to reconstruct the prior austenite from the as-quenched martensite phase. The dynamically recrystallised flow stress curves and microstructure were also predicted using cellular automata modelling. The results show an earlier onset of DRX with a decrease in strain rate or an increase in deformation temperature. The dynamically recrystallised grain size is also found to decrease with an increase in strain rate and a lowering of deformation temperature.

  16. Effects of Heat-Affected Zone Microstructure on Fracture Toughness of Two X70 Pipe Girth Welds (United States)

    Park, Dong-Yeob; Amirkhiz, Babak Shalchi; Gravel, Jean-Philippe; Wang, Yiyu; Li, Leijun; Zavadil, Renata; Liang, Jie; Liu, Pei; He, Anqiang; Arafin, Muhammad


    In the previous study, unstable brittle crack extensions were observed during ductile tearing from all the single-edge notched bend [SE(B)] specimens with an initial crack placed in heat-affected zone (HAZ), machined from one of the two studied X70 pipe girth welds, performed at 258 K (-15 °C). Thus their microstructures and properties have been investigated using optical microscopy, microhardness measurement, and advanced scanning electron microscopy and transmission electron microscopy so as to (1) characterize their metallographic properties including crystallographic texture and (2) correlate them with the unstable brittle crack occurrence and propagation. The results suggest that HAZ softening—strength loss—is a major factor responsible for the cleavage occurrence in the given HAZ specimens as it could induce a large local strain concentration by limiting plasticity in base metal when a ductile crack crosses from the HAZ to the base metal. The HAZ softening seems to be associated with the disappearance of pearlite packets in the HAZ region, which presumably occurred during welding, for the given material. High angle grain boundaries in the fine-grained HAZ appear to affect the direction of cleavage propagation at the point of cleavage initiation ( i.e., pop-in).

  17. Hardness and microstructural characterization of API 5L X70 steel pipes welded by HF/ERW process; Caracterizacao microestrutural e de dureza em tubos de aco API 5L X70 soldados pelo processo HF/ERW

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    Calcada, Mauricio Vieira; Voorwald, Herman Jacobus Cornelis; Nascimento, Marcelino Pereira do [UNESP, Guaratingueta, SP (Brazil). Faculdade de Engenharia


    The materials that stand in the manufacture of steel pipes are called API, that should have, high mechanical resistance, high corrosion resistance, high fatigue resistance, good weldability, and other properties. Thus, the purpose of this project was to evaluate the microstructure and hardness of welded joints by the HF/ERW process of API 5L X70 steel pipes. The microstructural analysis was performed using a surface finish with grit sizes from 220 to 25 {mu}m e polishing with diamond paste from 9 {mu}m to 0.05 {mu}m; the revelation was made with 3% Nital attack. The Vickers hardness was performed across the welded joint by 33 points to indentation. The results were: 80.5 {+-} 3.4% of ferrite and 19.5 {+-} 3.4% of perlite for microanalysis. As for hardness, the values were: 215.69 HV10 for weld line, 218.65 HV10 for ZTA and 218.95 HV10 for base metal. (author)

  18. A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel


    Zixuan Yang; Bo Kan; Jinxu Li; Lijie Qiao; Alex A. Volinsky; Yanjing Su


    Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and pro...

  19. A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel (United States)

    Yang, Zixuan; Kan, Bo; Li, Jinxu; Su, Yanjing; Qiao, Lijie; Volinsky, Alex A.


    Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance. PMID:29135912

  20. A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel

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    Zixuan Yang


    Full Text Available Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance.

  1. Development of high strength pipes grade API 5L X70 PSL2 offshore by the HFIW Process (High Frequency Induction Welding)

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    Cordeiro, Wilson R.; Melo, Luis C.R.; Gomes, Igor O.; Boni, Luiz P.; Sanctis, Marco A.M. di [Apolo Tubulars, Lorena, SP (Brazil)


    High strength pipes can be manufactured with excellency in dimensional tolerances, rapidity and efficiency through HFIW process (High Frequency Induction Welding). API 5L 6 5/8 x 0,374 in pipes were made of thin, hot rolled and coiled plates with dimensional 9,300 x 1.040,0 x 140.000 mm. Mechanical tests, chemical and microstructural analysis were performed. For the microstructural analysis, ferrite and perlitic structure were detected. All the results obtained are according to API 5L, 44{sup th} edition, 2008 for the grade API 5L X70 PSL2 Offshore. (author)

  2. Early generation pipeline girth welding practices and their implications for integrity management of North American pipelines

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    Amend, Bill [DNV Columbus, Inc., Yorba Linda, CA (United States)


    In response to the interest in ensuring the continued safe operation of vintage pipelines and the integrity management challenges related to those pipelines, PRCI sponsored in 2009 a project called {sup V}intage Girth Weld Defect Assessment - Comprehensive Study{sup .} Its objectives focused on girth welds made with the shielded metal arc welding (SMAW) process, particularly with regard to: review of approaches for evaluating the integrity of these welds; description of the typical characteristics and properties of SMAW vintage welds; determination of gaps in available information and technology that hinder effective integrity assessment and management of vintage girth welds. A very extensive literature review was performed as part of this project. Key findings include the following. The failure rate of early generation girth welds is low, especially when considering the rate of catastrophic failures. Pipeline girth welds are unlikely to fail unless subjected to axial strains that far exceed the strains related to internal pressure alone.

  3. Leak in spiral weld in a 16 inches gas pipeline

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    Fazzini, Pablo G.; Bona, Jeremias de [GIE S.A., Mar del Plata (Argentina); Otegui, Jose L. [University of Mar del Plata (Argentina)


    This paper discusses a failure analysis after a leak in the spiral weld of a 16 inches natural gas pipeline, in service since 1974. The leak was the result of the coalescence of two different defects, on each surface of the pipe wall, located in the center of the inner cord of the helical DSAW weld. Fractographic and metallographic studies revealed that the leak was a combination of three conditions. During fabrication of the pipe, segregation in grain boundary grouped in mid weld. During service, these segregations underwent a process of selective galvanic corrosion. One of these volumetric defects coincided with a tubular pore in the outer weld. Pigging of the pipeline in 2005 for cleaning likely contributed to the increase of the leak flow, when eliminating corrosion product plugs. Although these defects are likely to repeat, fracture mechanics shows that a defect of this type is unlikely to cause a blowout. (author)

  4. Strip specimen tests for pipeline materials and girth welds

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    Mohr, William C. [Edison Welding Institute (EWI), Columbus, Ohio (United States)


    Strip specimen testing of pipeline materials has been widely applied as a method of getting data relevant to the performance of pipelines under axial direction loading. Comparisons of strip specimen against smaller standard tests (round tensile bar, fracture toughness specimens, polished round bars) and against full-scale or large-scale testing will be explored. Data from early-generation pipe welds from the 1920's to the 1940's to the most recent materials for offshore reeled pipe will be used for examples. Strip samples can provide full thickness information to take account of varying material properties or imperfection distribution through the thickness. Strip samples can also accommodate measurement of effects of the original surface finish or weld surface shape. Strip samples have more design flexibility than standard tests, but must be designed to limit stress concentrations and effects of local bending. (author)

  5. The Investigation of Structure Heterogeneous Joint Welds in Pipelines

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    Lyubimova Lyudmila


    Full Text Available Welding joints of dissimilar steels don’t withstand design life. One of the important causes of premature destructions can be the acceleration of steel structural degradation due to cyclic mechanical and thermal gradients. Two zones of tube from steel 12H18N9T, exhibiting the structural instability at early stages of the decomposition of a supersaturated solid austenite solution, were subjected to investigation. Methods of x-ray spectral and structure analysis, micro hardnessmetry were applied for the research. Made the following conclusions, inside and outside tube wall surfaces of hazardous zones in welding joint have different technological and resource characteristics. The microhardness very sensitive to changes of metal structure and can be regarded as integral characteristic of strength and ductility. The welding processes are responsible for the further fibering of tube wall structure, they impact to the characteristics of hot-resistance and long-term strength due to development of ring cracks in the welding joint of pipeline. The monitoring of microhardness and structural phase conversions can be used for control by changes of mechanical properties in result of post welding and reductive heat treatment of welding joints.

  6. GMAW (Gas Metal Arc Welding) process development for girth welding of high strength pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, Vaidyanath; Daniel, Joe; Quintana, Marie [The Lincoln Electric Company, Cleveland, OH (United States); Chen, Yaoshan [Center for Reliable Energy Systems (CRES), Dublin, OH (United States); Souza, Antonio [Lincoln Electric do Brasil, Guarulhos, SP (Brazil)


    This paper highlights some of the results and findings from the first phase of a consolidated program co-funded by US Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA) and Pipeline Research Council Inc (PRCI) to develop pipe weld assessment and qualification methods and optimize X 100 pipe welding technologies. One objective of the program is to establish the range of viable welding options for X 100 line pipe, and define the essential variables to provide welding process control for reliable and consistent mechanical performance of the weldments. In this first phase, a series of narrow gap girth welds were made with pulsed gas metal arc welding (GMAW), instrumented with thermocouples in the heat affected zone (HAZ) and weld metal to obtain the associated thermal profiles, and instrumented to measure true energy input as opposed to conventional heat input. Results reveal that true heat input is 16%-22% higher than conventional heat input. The thermal profile measurements correlate very well with thermal model predictions using true energy input data, which indicates the viability of treating the latter as an essential variable. Ongoing microstructural and mechanical testing work will enable validation of an integrated thermal-microstructural model being developed for these applications. Outputs from this model will be used to correlate essential welding process variables with weld microstructure and hardness. This will ultimately enable development of a list of essential variables and the ranges needed to ensure mechanical properties are achieved in practice, recommendations for controlling and monitoring these essential variables and test methods suitable for classification of welding consumables. (author)

  7. Intelligent Control of Welding Gun Pose for Pipeline Welding Robot Based on Improved Radial Basis Function Network and Expert System


    Jingwen Tian; Meijuan Gao; Yonggang He


    Since the control system of the welding gun pose in whole‐position welding is complicated and nonlinear, an intelligent control system of welding gun pose for a pipeline welding robot based on an improved radial basis function neural network (IRBFNN) and expert system (ES) is presented in this paper. The structure of the IRBFNN is constructed and the improved genetic algorithm is adopted to optimize the network structure. This control system makes full use of the characteristics of the IRBFNN...

  8. Equipment for Preparing Pipeline Position Butts for Welding

    Directory of Open Access Journals (Sweden)

    Lobanov L.M.


    Full Text Available The results of developments of the Ye.O.Paton Electric Welding Institute and its specialized departments on the designing national equipment models for preparation during the assembly the edges and butt ends of pipeline position butts with the diameter from 14 up to 159 mm, repair and modernization of power engineering objects, including the power units of nuclear and heat electric stations, in chemical and machine building, at enterprises of oil-gas complex and other branches of industry are presented.

  9. Underwater Wet Repair Welding of API 5L X65M Pipeline Steel

    Directory of Open Access Journals (Sweden)

    Rogalski Grzegorz


    Full Text Available This paper presents results of the research of effect of polymer insulation of pipeline made of API 5L X65M steel as well as underwater wet welding parameters on properties of joints made by covered electrodes. Effect of heat input on structure and hardness of joints during repair of underwater pipeline was analyzed. Welding defects like microcracks, micro-lacks of fusion, slag inclusions, as well as HAZ hardness increase over an assumed acceptance criterion for welded joints in pipes without anticorrosion polymer insulation, were identified. A significant effect of polimer insulation on structure and properties of welded joints, was found.

  10. Hybrid laser-gas metal arc welding (GMAW) of high strength steel gas transmission pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Ian D.; Norfolk, Mark I. [Edison Welding Institute (EWI), Columbus, Ohio (United States)


    Hybrid Laser/arc welding process (HLAW) can complete 5G welds, assure weld soundness, material properties, and an acceptable geometric profile. Combining new lasers and pulsed gas metal arc welding (GMAW-P) has led to important innovations in the HLAW process, increasing travel speed for successful root pass welding. High power Yb fiber lasers allow a 10 kW laser to be built the size of a refrigerator, allowing portability for use on the pipeline right-of-way. The objective was to develop and apply an innovative HLAW system for mechanized welding of high strength, high integrity, pipelines and develop 5G welding procedures for X80 and X100 pipe, including mechanical testing to API 1104. A cost-matched JIP developed a prototype HLAW head based on a commercially available bug and band system (CRC-Evans P450). Under the US Department of Transportation (DOT) project, the subject of this paper, the system was used to advance pipeline girth welding productivity. External hybrid root pass welding achieved full penetration welds with a 4-mm root at a travel speed of 2.3-m/min. Welds were made 'double down' using laser powers up to 10 kW and travel speeds up to 3-m/min. The final objective of the project was to demonstrate the hybrid LBW/GMAW system under simulated field conditions. (author)

  11. Health monitoring of pipeline girth weld using empirical mode decomposition (United States)

    Rezaei, Davood; Taheri, Farid


    In the present paper the Hilbert-Huang transform (HHT), as a time-series analysis technique, has been combined with a local diagnostic approach in an effort to identify flaws in pipeline girth welds. This method is based on monitoring the free vibration signals of the pipe at its healthy and flawed states, and processing the signals through the HHT and its associated signal decomposition technique, known as empirical mode decomposition (EMD). The EMD method decomposes the vibration signals into a collection of intrinsic mode functions (IMFs). The deviations in structural integrity, measured from a healthy-state baseline, are subsequently evaluated by two damage sensitive parameters. The first is a damage index, referred to as the EM-EDI, which is established based on an energy comparison of the first or second IMF of the vibration signals, before and after occurrence of damage. The second parameter is the evaluation of the lag in instantaneous phase, a quantity derived from the HHT. In the developed methodologies, the pipe's free vibration is monitored by piezoceramic sensors and a laser Doppler vibrometer. The effectiveness of the proposed techniques is demonstrated through a set of numerical and experimental studies on a steel pipe with a mid-span girth weld, for both pressurized and nonpressurized conditions. To simulate a crack, a narrow notch is cut on one side of the girth weld. Several damage scenarios, including notches of different depths and at various locations on the pipe, are investigated. Results from both numerical and experimental studies reveal that in all damage cases the sensor located at the notch vicinity could successfully detect the notch and qualitatively predict its severity. The effect of internal pressure on the damage identification method is also monitored. Overall, the results are encouraging and promise the effectiveness of the proposed approaches as inexpensive systems for structural health monitoring purposes.

  12. Underwater Wet Repair Welding of API 5L X65M Pipeline Steel

    National Research Council Canada - National Science Library

    Grzegorz Rogalski; Dariusz Fydrych; Jerzy Łabanowski


    This paper presents results of the research of effect of polymer insulation of pipeline made of API 5L X65M steel as well as underwater wet welding parameters on properties of joints made by covered electrodes...

  13. Numerical simulation of temperature field in multiple-wire submerged arc welding of X80 pipeline steel (United States)

    Yan, Chunyan; Jiang, Han; Wu, Lichao; Kan, Chenxia; Yu, Wen


    Three dimensional (3D) finite element (FE) simulation was implemented to predict the temperature distribution during multiple-wire submerged arc welding (SAW) throughout the welded joint of X80 pipeline steel. A moving heat source model based on Goldak’s double-ellipsoid heat flux distribution was applied in the simulation to capture the heating effect of the welding arc. Effects of welding speed, wire spacing and leading wire current on temperature distribution were further investigated. The simulation results show that both welding speed and wire spacing have significant effects on welding temperature distribution in X80 pipeline steel welded joint.

  14. Intelligent Control of Welding Gun Pose for Pipeline Welding Robot Based on Improved Radial Basis Function Network and Expert System

    Directory of Open Access Journals (Sweden)

    Jingwen Tian


    Full Text Available Since the control system of the welding gun pose in whole-position welding is complicated and nonlinear, an intelligent control system of welding gun pose for a pipeline welding robot based on an improved radial basis function neural network (IRBFNN and expert system (ES is presented in this paper. The structure of the IRBFNN is constructed and the improved genetic algorithm is adopted to optimize the network structure. This control system makes full use of the characteristics of the IRBFNN and the ES. The ADXRS300 micro-mechanical gyro is used as the welding gun position sensor in this system. When the welding gun position is obtained, an appropriate pitch angle can be obtained through expert knowledge and the numeric reasoning capacity of the IRBFNN. ARM is used as the controller to drive the welding gun pitch angle step motor in order to adjust the pitch angle of the welding gun in real-time. The experiment results show that the intelligent control system of the welding gun pose using the IRBFNN and expert system is feasible and it enhances the welding quality. This system has wide prospects for application.

  15. Method to reduce arc blow during DC arc welding of pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Espina-Hernandez, J. H.; Rueda-Morales, G.L.; Caleyo, F.; Hallen, J. M. [Instituto Politecnico Nacional, Mexico, (Mexico); Lopez-Montenegro, A.; Perz-Baruch, E. [Pemex Exploracion y Produccion, Tabasco, (Mexico)


    Steel pipelines are huge ferromagnetic structures and can be easily subjected to arc blow during the DC arc welding process. The development of methods to avoid arc blow during pipeline DC arc welding is a major objective in the pipeline industry. This study developed a simple procedure to compensate the residual magnetic field in the groove during DC arc welding. A Gaussmeter was used to perform magnetic flux density measurements in pipelines in southern Mexico. These data were used to perform magnetic finite element simulations using FEMM. Different variables were studied such as the residual magnetic field in the groove or the position of the coil with respect to the groove. An empirical predictive equation was developed from these trials to compensate for the residual magnetic field. A new method of compensating for the residual magnetic field in the groove by selecting the number of coil turns and the position of the coil with respect to the groove was established.

  16. Development of a telerobotic welding virtual environment for nuclear pipeline maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Dong, N.; Li, H.C.; Gao, H.M.; Ni, J.; Wu, L. [Harbin Inst. of Technology (China). National Key Laboratory of Advanced Welding Production Technology


    Telerobotic welding is used to maintain nuclear pipelines in hazardous and narrow environments. This paper presented a virtual environment designed to both visualize and operate a telerobotic system. The system was designed to allow operators to handle the virtual robot at local sites using a keyboard or mouse as well as to control data transfer and the robot's motor. Sensor information transfer was directed from the robot to the virtual environment via photoelectricity encoder data, visual data, force data, laser disposed data and welding data. Sensor information was presented in the virtual environment. The virtual environment design included both modelling and calibration capabilities for designing static and dynamic objects. A kinematic analysis of the 9 degrees of freedom pipeline welding robot was presented. Pipeline calibration was conducted using a surface tracking strategy with a shared force control technique. Results of the study showed that the virtual environment increased the accuracy of the telerobotic system. 5 refs., 2 tabs., 8 figs.

  17. Anti-Thixotropic Analysis of Pipeline Metal Losses in Welded ...

    African Journals Online (AJOL)

    This paper examines the causes of metal loss induced by cutting wear within the internal walls of pipelines which could lead to unpredicted and unexpected pipeline failure and the attendant oil spillage in Nigeria. To determine the rate of wear, the flow properties were determined. Flow was found to be turbulent containing ...

  18. 75 FR 14243 - Pipeline Safety: Girth Weld Quality Issues Due to Improper Transitioning, Misalignment, and... (United States)


    ... Engineers (ASME) B31.8, Gas Transmission and Distribution Piping Systems or ASME B31.4 Pipeline... appurtenance. ASME B31.4, Figure 434.8.6(a)-(2), Acceptable Butt Welded Joint Design for Unequal Wall Thickness and ASME B31.8, Figure I5, Acceptable Design for Unequal Wall Thickness, give guidance for wall...

  19. Optimum Design and Development of High Strength and Toughness Welding Wire for Pipeline Steel (United States)

    Chen, Cuixin; Xue, Haitao; Yin, Fuxing; Peng, Huifen; Zhi, Lei; Wang, Sixu

    Pipeline steel with higher strength(>800MPa) has been gradually used in recent years, so how to achieve good match of base metal and weld deposit is very important for its practical application. Based on the alloy system of 0.02-0.04%C, 2.0%Mn and 0.5%Si, four different kinds of welding wires were designed and produced. The effects of alloy elements on phase transformation and mechanical properties were analyzed. Experimental results show that the designed steels with the addition of 2-4% Ni+Cr+Mo and 800MPa) and good elongation (>15%). The microstructure of deposits metal is mainly composed of granular bainite and M-A constituents with the mean size of 0.2-07μm are dispersed on ferritic matrix. The deposited metals have good match of strength (>800MPa) and impact toughness (>130J) which well meet the requirement of pipeline welding.

  20. Reasons for crack nucleation in welded joints of main gas-pipelines after a long-term operation (United States)

    Maruschak, P. O.; Bishchak, R. T.; Shlapak, L. S.; Panin, S. V.


    A crack of operational origin in the welded joint of the main gas pipeline is analyzed. The reasons for its nucleation and impact on technological microdefects that were formed earlier during the welding are found. Micromechanisms and stages of nucleation and propagation of the crack are investigated.


    Directory of Open Access Journals (Sweden)

    Mr. Pavel V. Bakhmatov


    Full Text Available Summary . The article focuses on the arc impulse frequency effect on the structure and properties of welded connections in aluminum pipeline systems hand-operated with argon-arc welding nonconsumable rod on MasterTig3500. It was revealed that the frequency of the welding current impulses plays an important role in the forming of the welded connection. The authors determined the optimal value of the welding current frequency significantly accelerating the welding process to ensure consistent quality of the weld. The authors detailed some features of cleaning assembly parts with a wire brush prior to welding process.

  2. Microstructure and mechanical properties of hard zone in friction stir welded X80 pipeline steel relative to different heat input

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Hakan, E-mail: [Engineering and Architecture Faculty, Mechanical Engineering Department, Uludag University, 16059 Gorukle-Bursa (Turkey); Nelson, Tracy W. [Mechanical Engineering Department, Brigham Young University, 435 CTB, Provo, UT 84602 (United States)


    The study was conducted to investigate the microstructure and mechanical properties of the hard zone in friction stir welded X80 pipeline steel at different heat inputs. Microstructural analysis of the welds was carried out using optical microscopy, transmission electron microscopy, and microhardness. Heat input during friction stir welding process had a significant influence on the microstructure and mechanical properties in the hard zone along the advancing side of the weld nugget. Based on the results, the linear relationships between heat input and post-weld microstructures and mechanical properties in the hard zone of friction stir welded X80 steels were established. It can be concluded that with decrease in heat input the bainitic structure in the hard zone becomes finer and so hard zone strength increases.

  3. Evaluation on ductile tearing properties of girth weld pipelines using SE(T) and SE(B) specimens

    Energy Technology Data Exchange (ETDEWEB)

    Mathias, Leonardo Luiz Siqueira; Ruggieri, Claudio [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Naval e Oceanica


    Predictive methodologies aimed at quantifying the impact of defects in oil and gas pipelines play a key role in safety assessment procedures of in-service facilities. Current methodologies for structural integrity assessments advocate the use of geometry dependent resistance curves so that crack-tip constraint in the test specimen closely matches the crack tip constraint for the structural component. Testing standards now under development to measure fracture resistance of pipeline steels (J and CTOD) most often employ single edge notched specimens under tension (SENT) to match a postulated defect in the structural component. This paper presents an investigation of the ductile tearing properties for a girth weld of an API 5L X80 pipeline steel using experimentally measured crack growth resistance curves (J-R curves). Testing of the girth weld pipeline steels employed side-grooved, clamped SE(T) specimen with center-crack weld and side-grooved, three-point bending SE(B) (or SENB) specimens to determine the J-R curves. The methods were compared in terms of geometry, relative crack size and crack-tip constraint, and the results were applied to a case study, to evaluate the degree of conservativeness in defect acceptance criteria. The tests involving SE(B) specimens are usually considered conservative, however, the comparison between this two methods may point an accurate alternative for girth weld assessments, since adequate geometry is adopted to describe accurately the structure's behavior. (author)

  4. Dry hyperbaric gas metal arc welding of subsea pipelines: experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Azar, Amin S.


    Ambitions in exploration of oil and gas fields at deeper water depth require continuous investigation and maintenance. The transportation pipelines laid in deep waters are both subjected to corrosion and buckling due to environmental phenomena. They may also often undergo branching (namely hot tapping) to redirect (or add to) the transportation paths. Mechanical joints and welding are both considered as available alternatives when sectioning and replacement of the pipes at shallow waters is necessary, yet, welding is more promising for deep waters where remote operation is central. Fusion welding on the other hand comprises several technological detractions for sound operations under high ambient pressures disregarding its low cost and flexibility. The foremost detracting phenomenon in the arc welding is called 'arc root constriction', which is defined as arc geometry shrinkage under the increased pressure. Consequently, the power delivery to the weld pool at different pressure levels is a major worry. Effects of ionization and dissociation energies of different gases and mixtures, partial pressure of environmental gases including hydrogen and oxygen, gasification and degasification of the weld metal, inclusions that affect the phase transformation, absorption and desorption kinetics, oxidation and deoxidation reactions and many more are the phenomena that can possibly be altered by the gas type and ambient pressure level. Spattering and fume generation is a problematic issue since the arc is rather unstable under high pressure. Thus, seeking the effect of different chamber gas mixtures on welding parameters, final microstructure and mechanical properties is the main objective of this work.Statistical analysis of the collected voltage and current waveforms is carried out to identify the source of arc misbehavior and instability (discussed in Paper I). The stochastic parameters is related to the electrical stability and resolved into a number of varying

  5. Pipeline welding with Flux Cored and Metal Cored Wire; Soldagem de dutos com processos Arame Tubular e de Alma Metalica

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ubirajara Pereira da [ITW Soldagem Brasil Miller-Hobart, Sao Paulo, SP (Brazil)


    Different welding process like SMAW, Semi-Automatic FCAW Gas-shielded and Self-shielded and Mechanized GMAW-MAG with Solid Wire are suggested to weld Transmission Pipelines. Presently, the largest extensions of Transmission Pipelines under construction, are in China like Lines West-East, Zong-Wu, Shan-Jing Fuxian and some others, totalizing about 8.000 km, and all using Semi-Automatic Self Shielded Flux Cored Arc Welding Process. Also, several papers and magazines that covers Transmission Pipelines Welding, not frequently mention Operational aspects of the process and some other variables like environment and site geography. This presentation intends to cover some of the Operational aspects of the Flux Cored Arc Welding and GMAW-Metal Cored in order to give sufficient information for Construction, Engineering, Projects e Contractors so they can evaluate these Process against the SMAW or even Mechanized Systems, considering the Operation Factor, Efficiency and Deposition Rate. We will not cover operational details of the GMAW Mechanized Systems but only suggest that be evaluated the possibility to replace the GMAW-Solid Wire by the GMAW-Metal Cored Wire. (author)

  6. Soldagem em operação de dutos de alta resistência e baixa espessura com ênfase nas trincas a frio In-service welding of pipelines in high strength low thickness with emphasis on cold cracks

    Directory of Open Access Journals (Sweden)

    Aldo Santos Pereira


    Full Text Available O objetivo deste trabalho foi avaliar a ocorrência de trincas a frio quando da soldagem de dutos em operação. Foram executados dois conjuntos de experimentos: o primeiro denominado de experimento "F", em que foi variada a folga entre a calha e o tubo, e utilizados metal de base e de adição de alto carbono equivalente; o segundo denominado de experimento "R", em que foi imposta alta restrição à junta soldada e, promovido o resfriamento rápido mediante fluxo de água no interior do tubo. Foram feitas as soldagens com os seguintes processos e materiais: processo eletrodo revestido (SMAW, tubo e calha em aço ASTM A 335 P5, metal de adição AWS E 8018-B8 (experimento "F". Processos MIG/MAG pulsado (GMAW-P e arame tubular auto-protegido (FCAW-S, tubo e calha em aço API 5L X70, metais de adição AWS ER 80S-G e AWS E 71T-11, respectivamente (experimento "R". Para detectar as trincas a frio foram realizados exame visual e a inspeção com líquidos penetrantes. Adicionalmente as soldas foram avaliadas por macrografia e medição de dureza. Não foram detectadas trincas, apesar da utilização de metais de base e de adição com alto carbono equivalente e da junta com alta restrição, com o objetivo de aumentar as tensões. Admite-se que não houve fissuração devido ao uso de processos e/consumíveis com baixo teor de hidrogênio.The aim of this study was to evaluate the occurence of cold cracks associated with in-service welding of pipelines. Two sets of experiments were performed : the first of them was called experiment "F", where the gap between sleeve and pipe was varied and base and weld metal of high carbon equivalent were used, the second set of experiment was denominated "R", when higher restriction was imposed to the welded joint, which was simultaneously more rapid cooled by water flow within the pipe. The welds were made ​​with the following procedures and materials: shielded metal arc welding (SMAW of tube and pipeline

  7. Determination of Elements and Carbon Content of Stainless Steel Welded Pipeline


    Pavel Hudeček; Petr Dostál


    Find out defects or problems of welds are not so simple from time to time. Specially, if weld has been made in rough environmental conditions like high temperature, dusty wind and humidity. It is important to assure have good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, difficult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosit...

  8. Determination of Elements and Carbon Content of Stainless Steel Welded Pipeline

    Directory of Open Access Journals (Sweden)

    Pavel Hudeček


    Full Text Available Find out defects or problems of welds are not so simple from time to time. Specially, if weld has been made in rough environmental conditions like high temperature, dusty wind and humidity. It is important to assure have good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, difficult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosity, lack of penetration and distortion can compromise the strength of the base metal, as well as the integrity of the weld. According of site inspection, there were suspicion of inclusions, leaker or segregation in root of weld. Surface treatment after welding and keep the intervals between single welds to not overheat the pipes. To recognize those suspicions, mechanical testing around weld joint, determination of carbon content and inductively coupled plasma atomic emission spectroscopy will be done.

  9. Thermal Behavior of an HSLA Steel and the Impact in Phase Transformation: Submerged Arc Welding (SAW) Process Approach to Pipelines (United States)

    Costa, P. S.; Reyes-Valdés, F. A.; Saldaña-Garcés, R.; Delgado, E. R.; Salinas-Rodríguez, A.

    Heat input during welding metal fusion generates different transformations, such as grain growth, hydrogen cracking, and the formation of brittle structures, generally associated with the heat-affected zone (HAZ). For this reason, it is very important to know the behavior of this area before welding. This paper presents a study of the thermal behavior and its effect on phase transformations in the HAZ, depending on cooling rates (0.1-200 °C/s) to obtain continuous cooling transformation (CCT) curves for an high-strength low-alloy (HSLA) steel. In order to determine the formed phases, optical microscopy and Vickers microhardness measurement were used. The experimental CCT curve was obtained from an HSLA steel, and the results showed that, with the used cooling conditions, the steel did not provide formation of brittle structures. Therefore, it is unlikely that welds made by submerged arc welding (SAW) may lead to hydrogen embrittlement in the HAZ, which is one of the biggest problems of cracking in gas conduction pipelines. In addition, with these results, it will be possible to control the microstructure to optimize the pipe fabrication with SAW process in industrial plants.

  10. Welding. (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This curriculum guide is designed for use by South Carolina vocational education teachers as a continuing set of lesson plans for a two-year course on welding. Covered in the individual sections of the guide are the following topics: an orientation to welding, oxyacetylene welding, advanced oxyacetylene welding, shielded metal arc welding, TIG…

  11. An automatic approach for nondestructive radiographic inspection of pipeline weld joint; Uma abordagem automatica aplicada a inspecao radiografica nao-destrutiva de soldas em tubulacoes

    Energy Technology Data Exchange (ETDEWEB)

    Felisberto, Marcelo K.; Schneider, Guilherme A.; Centeno, Tania M.; Arruda, Lucia V.R. de [Centro Federal de Educacao Tecnologica do Parana, Curitiba, PR (Brazil). CPGEI - Programa de Pos-graduacao em Engenharia Eletrica e Informatica Industrial


    The current work contributes to the research in the area of pipelines non-destructive testing by presenting new methodologies for the automatic analysis of welds radiographs. Object recognition techniques based on genetic algorithms were used for the automatic weld bead detection. In addiction, an image digital filter was also tested in the weld bead images and, as a result, supposed defects are highlighted, making them easier to be detected. These methodologies were tested for 120 digital radiographs from carbon steel pipeline welded joints. These images were acquired by a storage phosphor system, using double-wall radiographic exposing technique with single-wall radiographic viewing, according to the ASME V code. As a result, even human vision hard-perceptible defects are automatically highlighted and extracted from the whole image to be separately analyzed. (author)

  12. Automatic welding on the Hauts-de-France pipeline; Le soudage automatique sur l`artere des Hauts-de-France

    Energy Technology Data Exchange (ETDEWEB)

    Thebault, Y.; Bichet, J.; Darderet, Ch. [Gaz de France (GDF), 75 - Paris (France)


    The NorFra pipeline to carry Norwegian gas to France was inaugurated officially by France`s Prime Minister Lionel Jospin on October 9, 1998 at Dunkirk, France. Preliminary work on the Hauts-de-France pipeline which connects NorFra with the Paris area was covered in the October 1997 issue of Gaz d`Aujourd`hui. This contribution reviews automatic welding work on this new trunk line. (authors)

  13. The Influence Of Repair Welded Joint On The Life Of Steam Pipeline Made Of Cr-Mo Steel Serviced Beyond The Calculated Working Time

    Directory of Open Access Journals (Sweden)

    Zieliński A.


    Full Text Available The aim of the paper was to examine the influence of repair welded joints on the service life of steam pipelines for over 220 000 hours of service in creep conditions. The research included the study of the microstructure using scanning microscopy, the tests on mechanical properties at room and elevated temperature, determining the nil ductility transition temperature, and short-time creep tests to determine the residual life of the material. The tests allowed determining the time of further safe operation of elements of the steam pipeline with a repair welded joint, with reference to the base material, and the welded joint after service. The assessment of residual life and disposable residual life, and at the same time determining the possible time of further safe operation, has an essential meaning in the case of elements serviced considerably beyond the calculated working time.

  14. Joining of Materials with Diferent Properties Through Submerged Arc Welding Process and Destructive and Non-Destructive Testing of the Joints

    Directory of Open Access Journals (Sweden)

    Yakup Kaya


    Full Text Available In this study, X60, X65 and X70 steels used in petroleum and natural gas pipeline were joined with Submerged Arc Welding by using different type of welding fluxes (LN761 and P223 and wires (S1 and S2Mo. Initially, visual and radiographic inspection techniques were subjected to welded joints for determining surface and subsurface defects. After that, spectral analyses were carried out in order to determine the compositions of wire-flux-base metal on the joints. Impact toughness test were performed for determining toughness properties the joints. Furthermore, hardness and microstructure studies were also carried out on the samples. As a result of the visual and radiographic inspection on the welded samples, there were no weld defects on joints were observed. It was clearly understood that carbon ratio in the compositions of weld metal higher than base metal but lower than filler metal in terms of spectral analyses results. According to impact toughness test results, the joints obtained by using S2Mo welding wire and P223 welding flux had better impact toughness value than the joints obtained by S1 welding wire and LN 761 welding flux. With respect to hardness test, the highest hardness values were measured on weld metal. When the microstructure images were examined, it is clearly understood that similar images for all the joints were shown adjacent zones to weld metals heat affected zones and welding boundary, due to heat input constant.

  15. Microstructures and Mechanical Properties of Friction Tapered Stud Overlap Welding for X65 Pipeline Steel Under Wet Conditions (United States)

    Xu, Y. C.; Jing, H. Y.; Han, Y. D.; Xu, L. Y.


    This paper exhibits a novel in situ remediation technique named friction tapered stud overlap welding (FTSOW) to repair a through crack in structures and components in extremely harsh environments. Furthermore, this paper presents variations in process data, including rotational speed, stud displacement, welding force, and torque for a typical FTSOW weld. In the present study, the effects of welding parameters on the microstructures and mechanical properties of the welding joints were investigated. Inapposite welding parameters consisted of low rotational speeds and welding forces, and when utilized, they increased the occurrence of a lack of bonding and unfilled defects within the weld. The microstructures with a welding zone and heat-affected zone mainly consisted of upper bainite. The hardness value was highest in the welding zone and lowest in the base material. During the pull-out tests, all the welds failed in the stud. Moreover, the defect-free welds broke at the interface of the lap plate and substrate during the cruciform uniaxial tensile test. The best tensile test results at different depths and shear tests were 721.6 MPa and 581.9 MPa, respectively. The favorable Charpy impact-absorbed energy was 68.64 J at 0 °C. The Charpy impact tests revealed a brittle fracture characteristic with a large area of cleavage.

  16. Uma breve revisão histórica do desenvolvimento da soldagem dos aços API para tubulações A brief history review of development on API steels welding for pipeline

    Directory of Open Access Journals (Sweden)

    Jaime Casanova Soeiro Junior


    Full Text Available Este trabalho enfoca o desenvolvimento dos aços API para tubulações desde o aço API 5L X42, desenvolvido em 1948, através de laminação a quente seguida de tratamento térmico. Desde então foram feitos diferentes desenvolvimentos visando aumentar a resistência mecânica e a tenacidade, além de melhorar a soldabilidade. Entre eles, a adição de elementos de liga, produzindo os aços ARBL e a utilização de rotas de processamento termomecânico durante a laminação. Inicialmente a rota utilizada era a laminação a quente controlada (TMCR, com utilização de elemento microligante como Nb para os aços X60 e o conjunto Nb e V para os aços X65 e X70, associado a uma redução do teor de carbono. Posteriormente foi implantada a rota de fabricação do aço por laminação controlada seguida de resfriamento controlado (TMCP, com redução de carbono e adição de Nb e Ti para os aços X80, e adições de Mo, Nb, Be Ti para os X100. A redução do carbono foi motivada também para melhorar a sua soldabilidade e, por este motivo, estes aços são soldados por diferentes processos de soldagem, como o eletrodo revestido. Desenvolvimentos recentes com raiz feita com MAG-TC e enchimento com arame tubular tem dado resultados animadores.This paper is a brief history on the development of pipelines steels since the API 5L X42 steel, developed in 1948 by hot rolling followed by heat treatment. Subsequently different developments were made to increase the strength and toughness of these materials, and to improve their weldability. Among them, the addition of microalloying elements, producing HSLA steels and thermomechanical processing routes during hot rolling. Initially the route used was the controlled hot rolling (TMCR, together with microalloying element such as Nb for X60 steel and Nb plus V for X65 and X70 steels, associated with a reduction in carbon content. Later, the thermomechanical controlled process (TMCP manufacturing route was

  17. Welding. (United States)

    Cowan, Earl; And Others

    The curriculum guide for welding instruction contains 16 units presented in six sections. Each unit is divided into the following areas, each of which is color coded: terminal objectives, specific objectives, suggested activities, and instructional materials; information sheet; transparency masters; assignment sheet; test; and test answers. The…

  18. Construction of new tie-in in the Bolivia-Brazil Gas Pipeline (GASBOL) using hot tapping techniques; Derivacao do Gasoduto Bolivia-Brasil com a tecnica de hot-tapping

    Energy Technology Data Exchange (ETDEWEB)

    Frisoli, Caetano [TRANSPETRO - PETROBRAS Transportes, Rio de Janeiro, RJ (Brazil); Frota, Cristiane Souto; Leite Filho, Ismael Casono; Lobao Filho, Jesualdo Pereira; Saavedra, Marcelo Curto [Transportadora Brasileira Gasoduto Bolivia-Brasil, S.A., Rio de Janeiro, RJ (Brazil)


    To supply 2,4 MM m3/d of natural gas to Tres Lagoas thermo electric plant, it was necessary to install a new delivery point of 12'' in the 32'' trunk line of Bolivia-Brazil gas pipeline. The most efficient method for executing new delivery points and maintenance repairs in pipelines is using the 'hot-tapping' technique, because there is no need to stop flow and blow down lines. This paper shows the project, specifications, planning and a detailed job execution to support this new city-gate, using a T split sleeve welded in the pipeline, explaining all the activities. Complex and innovative aspects related to the welding and inspection processes, executed in a API 5L X70 pipe at 92 kgf/cm{sup 2}, are also reported. (author)

  19. Effect of Microstructure on Hydrogen Diffusion in Weld and API X52 Pipeline Steel Base Metals under Cathodic Protection

    Directory of Open Access Journals (Sweden)

    R. C. Souza


    Full Text Available The aim of this research was to evaluate the influence of microstructure on hydrogen permeation of weld and API X52 base metal under cathodic protection. The microstructures analyzed were of the API X52, as received, quenched, and annealed, and the welded zone. The test was performed in base metal (BM, quenched base metal (QBM, annealed base metal (ABM, and weld metal (WM. Hydrogen permeation flows were evaluated using electrochemical tests in a Devanathan cell. The potentiodynamic polarization curves were carried out to evaluate the corrosion resistance of each microstructure. All tests were carried out in synthetic soil solutions NS4 and NS4 + sodium thiosulfate at 25°C. The sodium thiosulfate was used to simulate sulfate reduction bacteria (SRB. Through polarization, assays established that the microstructure does not influence the corrosion resistance. The permeation tests showed that weld metal had lower hydrogen flow than base metal as received, quenched, and annealed.

  20. 49 CFR 192.235 - Preparation for welding. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Preparation for welding. 192.235 Section 192.235... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.235 Preparation for welding. Before beginning any welding, the welding surfaces must be clean and free of any material that...

  1. Effect of the welding process on the microstructure and microhardness of API 5L X80 steel welded joint used for oil transportation pipeline; Efeito do processo de soldagem sobre a microestrutura e a microdureza de juntas soldadas de aco API 5L X80 usado em tubulacoes para transporte de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Alves, R.T.P.; Albuquerque, S.F. [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Maciel, T.M.; Almeida, D.M.; Santos, M.A.


    This study had as objective to evaluate the microstructure and microhardness of API 5L X80 steel welded joints, used for pipelines to transport oil and gas, using the Shield Metal Arc Welding process with pre- heating temperature of 200 deg C and 400 deg C and the AWS E8010G electrode as filler metal. For this, besides the microhardness of the welded joint, the weld metals percentiles of micro-constituents and of columnar and regenerated grains and the medium size and extension of the heat affected zone were evaluated. The percentage of acicular ferrite in weld metal ranged from 13% to 33% which generated values of microhardness from 114 HV to 309 HV. (author)

  2. Evaluation of Hydrogen Cracking in Weld Metal Deposited using Cellulosic-Coated Electrodes (United States)


    Cellulosic-coated electrodes (primarily AWS EXX10-type) are traditionally used for "stovepipe" welding of pipelines because they are well suited for deposition of pipeline girth welds and are capable of high deposition rates when welding downhill. De...

  3. Assessment of Ductile-to-Brittle Transition Behavior of Localized Microstructural Regions in a Friction-Stir Welded X80 Pipeline Steel with Miniaturized Charpy V-Notch Testing (United States)

    Avila, Julian A.; Lucon, Enrico; Sowards, Jeffrey; Mei, Paulo Roberto; Ramirez, Antonio J.


    Friction-stir welding (FSW) is an alternative welding process for pipelines. This technology offers sound welds, good repeatability, and excellent mechanical properties. However, it is of paramount importance to determine the toughness of the welds at low temperatures in order to establish the limits of this technology. Ductile-to-brittle transition curves were generated in the present study by using a small-scale instrumented Charpy machine and miniaturized V-notch specimens (Kleinstprobe, KLST); notches were located in base metal, heat-affected, stirred, and hard zones within a FSW joint of API-5L X80 Pipeline Steel. Specimens were tested at temperatures between 77 K (-196 °C) and 298 K (25 °C). Based on the results obtained, the transition temperatures for the base material and heat-affected zone were below 173 K (-100 °C); conversely, for the stirred and hard zones, it was located around 213 K (-60 °C). Fracture surfaces were characterized and showed a ductile fracture mechanism at high impact energies and a mixture of ductile and brittle mechanisms at low impact energies.

  4. 49 CFR 195.224 - Welding: Weather. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions that...

  5. Development of API 5L X70 and X80 in the Brazilian Vallourec and Mannesmann Tubes industry; Desenvolvimento de acos API 5L X70 e X80 na Vallourec e Mannesmann Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Julio M. Silveira e; Carvalho, Ricardo N. de [Vallourec and Mannesmann Tubes - V e M do Brasil, Belo Horizonte, MG (Brazil)


    The demand for seamless pipes with resistance higher than those for API 5L X60 and X65 grades has increased in the last years. They are traditionally used up to now for applications on rigid risers for production and exportation and line pipes for oil and gas. In the case of seamless pipes, the great challenge is to fulfill the requirements of mechanical properties for X70 and X80 grades, quenched and tempered, with values of carbon equivalent low enough to assure a good weldability. This paper presents the results obtained by Vallourec and Mannesmann Tubes - V and M do Brazil on producing seamless pipes of X70 and X80 API grades, with outside diameter lower than 8 5/8{sup (} 219,1 mm ) and wall thickness up to 0,562{sup (} 14,3 mm ). Results of tensile, Charpy notch impact resistance and hardness tests are shown. Hydrogen-Induced and Environmental Cracking tests were also carried out, since for some applications is required a good resistance to these kinds of embrittlement mechanisms. The mechanical properties, microstructure and physical characteristics of welded joints were also evaluated. The results obtained up to now are quite promising, showing good suitability to the aimed final applications. (author)

  6. Study of API 5L X70 steel corrosion processes when in contact with some Brazilian soils; Estudo dos processos de corrosao de acos API 5L X70 em contato com alguns dos solos do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Sergio Luis de


    Pipelines, fuel storage tanks and other metallic structures are in permanent contact and exposed to different types of soils, of horizons or layers, or of soil aggressiveness. This interaction may cause expressive damages to the environment and to the planned work. Contamination may occur due to leakage of stored products, splitting during transportation, accidents caused by pipelines without extensive maintenance. The result of these accidents could be, among others, some financial losses. In order to recognize the dynamic interactions between metallic surfaces and the environment it is crucial to have preventive actions and to develop better-applied materials. API steel 5L X70 has been used in structures of low and high pressure with high mechanical strength and corrosion and, even so, it is susceptible to etching corrosion since it is in contact with different environments from mangrove regions to industrial environments. The present case evaluated the role of 5L X70 API steel in contact with different soil horizons representative of the Brazilian soil. This investigation correlated chemical species with solute ions in soil solution, secondary and primary phase minerals besides physical and chemical characteristics as pH, electric conductivity, total dissolved solids, among others, to the results of corrosion resistance and ways of corrosion. The evaluation was carried out using x-ray diffractometry, scanning electron microscopy, total reflection x-ray fluorescence, fuel injection flow besides texture and gravimetric analyses to soil characterization and mineralogy, identification of corrosion products, soil solution analyses, evaluation of tested materials and classification of ways and types of corrosion. This was an attempt to integrate the data to a better understanding of the process involving reagents and products. The results showed that different soil horizons such as different types of analyzed soils produce specific etching in metallic structures

  7. Historical case - welding on service in Brazil Bolivia gas pipeline at 92 Bar of pressure, in Tres Lagoas, Mato Grosso do Sul, Brazil; Caso historico: execucao de soldagem em operacao no gasoduto Bolivia-Brasil a pressao de 92 BAR, em Tres Lagoas, Mato Grosso do Sul, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Carlos Renato Aragonez de [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil)]|[PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Lobao Filho, Jesualdo Pereira [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil); Alcatrao, Mauro dos Santos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)


    The Bolivia-Brazil Natural Gas Pipeline - GASBOL - begins in the city of Santa Cruz of La Sierra, in Bolivia, arriving in Canoas (RS), in Brazil, traveling an extension of 3.150 km. TBG is the owner and operator from 2.593 km in Brazilian soil, with maximum nominal diameter 32 inches, capacity of transportations until 30 million cubic meter a day, and MAOP 100 bar. This work presents the steps for the qualification the welding procedure and the jobs for the welding in service at 92 bar of pressure, the measures to guarantee the integrity of the gas pipeline, including lines support, requirements for hydrostatic testing and the main equipment used during the jobs. It is made reference to an accident happened several month after in service welding in gas pipeline and presents the respective cause. (author)

  8. Residual stress evaluation by X-Ray diffraction and hole-drilling in an API 5L X70 steel pipe bent by hot induction

    Energy Technology Data Exchange (ETDEWEB)

    Ceglias, Rodrigo Braga; Alves, Juciane Maria; Botelho, Ramon Alves; Baeta Junior, Eustaquio de Souza; Santos, Igor Cuzzuol dos; Moraes, Nicki Robbers Darciano Cajueiro de; Oliveira, Rebeca Vieira de; Diniz, Saulo Brinco; Brandao, Luiz Paulo, E-mail: [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Mecanica e de Materiais


    The API 5L X70 steel is used in high-pressure gas transmission pipelines. Because of this, knowledge of presence of residual stress and their magnitude is important to assess the material integrity in service. For the pipeline manufacturing, tubes need to be curved which is often made using the hot induction bending process. This process can introduce different residual stress depending of tube position. For this research, in order to evaluate the residual stress, was used an API 5L X70 tube that was previously curved by hot induction process. Samples were taken from the extrados, intrados, neutral line and straight section of the curved tube. Residual stresses were studied by two conventional methods: X-Ray Diffraction (XRD) and Hole-Drilling, which are destructive and non-destructive methods, respectively, in order to assess their qualitative responses. Each of these methods presents particular methodologies in sample preparation and material analysis, but also they differ in factors such time consumption and cost of the analysis. The qualitative responses obtained by the two different methods were comparable and satisfactory and pointed out the existence of a compressive residual stress state in steel pipe. (author)

  9. 49 CFR 179.11 - Welding certification. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding certification. 179.11 Section 179.11 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Design Requirements § 179.11 Welding certification. (a) Welding procedures, welders and fabricators shall...

  10. Pipeline engineering

    CERN Document Server

    Liu, Henry


    PART I: PIPE FLOWSINTRODUCTIONDefinition and Scope Brief History of PipelinesExisting Major PipelinesImportance of PipelinesFreight (Solids) Transport by PipelinesTypes of PipelinesComponents of PipelinesAdvantages of PipelinesReferencesSINGLE-PHASE INCOMPRESSIBLE NEWTONIAN FLUIDIntroductionFlow RegimesLocal Mean Velocity and Its Distribution (Velocity Profile)Flow Equations for One-Dimensional AnalysisHydraulic and Energy Grade LinesCavitation in Pipeline SystemsPipe in Series and ParallelInterconnected ReservoirsPipe NetworkUnsteady Flow in PipeSINGLE-PHASE COMPRESSIBLE FLOW IN PIPEFlow Ana

  11. Lay Pipeline Abandonment Head during Some

    African Journals Online (AJOL)


    Dec 1, 2016 ... computations and analysis do not cover adequately the effect of number of cyclic wave loading on the girth welds on long exposure period, especially as certain degree of weld surface and buried imperfections are often allowed during pipeline fabrication. In a normal practice, stoppage of offshore pipe-lay.

  12. Explosive Welding of Pipes (United States)

    Drennov, Oleg; Drennov, Andrey; Burtseva, Olga


    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. Explosive welding of cylindrical surfaces is performed by launching of welded layer along longitudinal axis of construction. During this procedure, it is required to provide reliable resistance against radial convergent strains. The traditional method is application of fillers of pipe cavity, which are dense cylindrical objects having special designs. However, when connecting pipes consecutively in pipelines by explosive welding, removal of the fillers becomes difficult and sometimes impossible. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe.

  13. Controlled short-circuiting MIG-MAG welding process and procedures applied to the root pass in pipeline construction; Processo de soldagem MIG/MAG em curto-circuito controlado e procedimentos aplicados ao passe de raiz na construcao de linhas dutoviarias

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Regis H.G. e; Gohr Junior, Raul; Weck, Leonardo W.A. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Soldagem e Mecatronica (LABSOLDA)


    The work deals with the study and development of the Controlled Short-Circuiting MIG/MAG Welding Process (CCC) and procedures for the root pass on pipes, in pipelines construction. The developed process (CCC) consists in an semi-automatic slag free operation, yielding higher productivity than the Coated Electrode and TIG processes, with satisfactory properties on the root weld. The significant influence of the welding over the time schedule and construction cost makes the development of this technology attractive, in order to become available at low cost, enhancing the companies' competitiveness in the globalized oil sector. The developed system, a MIG/MAG variant, features the advantages of short-circuiting metal transfer and avoids its inconveniences (mainly with high CO{sub 2} content gases), enabling its use on pipes root welding. This is possible through current waveform control, providing process and weld pool stability. Procedures for the root pass were determined for each of the welding positions reached in thick walled pipes welding, with the CCC. Also, the low welder training time was notable. (author)

  14. Depressurization of a spread of Brazil-Bolivia gas pipeline and the emergency repair of a weld crack in a instrument derivation at Campo Grande compression station; Despressurizacao de trecho do gasoduto Bolivia-Brazil para reparo emergencial de trinca em uma derivacao de instrumento de temperatura na Estacao de Compressao de Campo Grande - MS

    Energy Technology Data Exchange (ETDEWEB)

    Dietrich, Carlos Ribeiro; Leite Junior, Ismael Casano [TBG - Transportadora Brasileira Gasoduto Bolivia Brasil S.A., Rio de Janeiro, RJ (Brazil)


    The purpose of this paper is to report the actions taken to repair a gas leak, at an original pressure of 100 kgf/cm{sup 2}, occurred due to a 1 1/2'' branch pipe weld crack, located on the 24'' Campo Grande - Mato Grosso do Sul Compression Station discharge pipe. This branch pipe was used to a thermo well installation and was submitted to an additional strength caused by thermo well vibration. The weld repair actions required an urgent depressurization of a 33 km spread of Bolivia-Brazil Pipeline in a timely manner, to avoid any negative impact in the operational schedule. (author)

  15. The effect of plastic strain at coiling temperatures on the hardness of Grade 483 (X70) steel

    Energy Technology Data Exchange (ETDEWEB)

    Wiskel, J.B.; Niemi, E.; Lu, J.; Ivey, D.G.; Henein, H. [Alberta Univ., Edmonton, AB (Canada). Advanced Materials Processing Lab


    This paper presents the results of a study which examined the hardness of Grade 483 (API X70) microalloyed steel in terms of the relationship between the processing parameters of the final coil temperature, cooling rate and imposed strain. Such steels are commonly used for petroleum pipelines because of their high strength, toughness and good weldability. The yield strength of the steel can be increased by a thermomechanical controlled process (TMCP) known as precipitation strengthening. This study considered the enhancement of fine nanocarbides in the ferrite microstructure. Processing changes that enhance the nucleation, while minimizing growth of these fine nanocarbides are needed. One method to improve nucleation rate is through the controlled deformation of the steel immediately following laminar, cooling and prior to coiling. The magnitude of plastic deformation, as well as the cooling rate during laminar cooling and the coiling temperature, all play a role on the kinetics of fine precipitate formation. In order to understand the relationship between the processing parameters of the final coil temperature, cooling rate and imposed strain, a simulated TMCP processing schedule was undertaken using a Gleeble thermo-mechanical test apparatus. A coiling temperature between 400 and 500 degrees C had little or no effect on the hardness of the steel for the conditions studied. However, hardness was found to increase with decreased apparent cooling rate, possibly due to enhanced precipitation. The study revealed that precipitation enhancement can be achieved through longer times at higher temperature or by the application of sufficient plastic deformation. It was concluded that further studies are needed to define the correct combination of cooling rate, coiling temperature and imposed strain that will further increase sample hardness via enhanced carbide precipitation. 11 refs., 1 tab., 5 figs.

  16. The Effect of Chemical Composition on Microstructure and Properties of Intercritically Reheated Coarse-Grained Heat-Affected Zone in X70 Steels (United States)

    Zhu, Zhixiong; Kuzmikova, Lenka; Li, Huijun; Barbaro, Frank


    The current study investigates the effect of different levels of Ti, N, and Ti/N ratios on microstructure and properties in the intercritically reheated coarse-grained heat-affected zone (ICCGHAZ) of two-pass submerged arc welds in API 5L grade X70 pipe. Gleeble simulation was employed to reproduce the ICCGHAZ of actual welds. Hardness and Charpy V-notch (CVN) tests were performed on the simulated samples. The microstructure of simulated ICCGHAZ was characterized by optical microscopy and scanning electron microscopy (SEM). LePera color etching technique was employed to identify and quantify the martensitic-austenitic (M-A) constituent. Results show that the simulated ICCGHAZ exhibited extremely low toughness, but in the studied range of Ti and N, there was no correlation with Ti/N ratio. The beneficial effect of near-stoichiometric Ti/N ratio observed in coarse-grained heat-affected zone (CGHAZ) did not translate to ICCGHAZ. This was because of the negative effect of the blocky M-A constituent formed on prior austenite grain boundaries.


    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; Nancy Porter; Mike Sullivan; Chris Neary


    The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforced composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created

  18. 49 CFR 195.216 - Welding: Miter joints. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Miter joints. 195.216 Section 195.216 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.216 Welding: Miter joints. A miter joint is not permitted (not including...

  19. 49 CFR 195.226 - Welding: Arc burns. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Arc burns. 195.226 Section 195.226 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.226 Welding: Arc burns. (a) Each arc burn must be repaired. (b) An arc burn may...

  20. 49 CFR 195.208 - Welding of supports and braces. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding of supports and braces. 195.208 Section 195.208 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.208 Welding of supports and braces. Supports or braces may...

  1. Effect of natural aging on the microstructural regions, mechanical properties, corrosion resistance and fracture in welded joints on API5L X52 steel pipeline

    Directory of Open Access Journals (Sweden)

    Vargas-Arista, Benjamín


    Full Text Available A characterization study was done to analyze how microstructural regions affect the mechanical properties, corrosion and fractography of the Heat Affected Zone (HAZ, weld bead and base metal for pipe naturally aged for 21 years at 30 °C. Results showed that microstructures exhibited damage and consequently decrease in properties, resulting in over-aged due to service. SEM analysis showed that base metal presented coarse ferrite grain. Tensile test indicated that microstructures showed discontinuous yield. Higher tensile strength was obtained for weld bead, which exhibited a lower impact energy in comparison to that of HAZ and base metal associated with brittle fracture by trans-granular cleavage. The degradation of properties was associated with the coarsening of nano-carbides observed through TEM images analysis, which was confirmed by SEM fractography of tensile and impact fracture surfaces. The weld bead reached the largest void density and highest susceptibility to corrosion in H2S media when compared to those of the HAZ and base metal.Se realizó un estudio de caracterización para analizar cómo la microestructura afecta a las propiedades mecánicas, corrosión y fractura de la zona afectada por calor (ZAC, soldadura y metal base para tubería envejecida naturalmente durante 21 años a 30 °C. Los resultados indicaron que las microestructuras presentaron daño y consecuentemente reducción en propiedades mecánicas, como consecuencia del envejecimiento por servicio. El estudio mediante MEB mostró que el metal base presenta grano ferrítico grueso. La prueba de tensión indicó que las microestructuras mostraron fluencia discontinua. La mayor resistencia a la tracción se presentó en la soldadura, la cual alcanzó menor energía de impacto en comparación con la ZAC y metal base asociado con fractura frágil por clivaje transgranular. La degradación de las propriedades está en relación con el engrosamiento de nanocarburos observados a

  2. Effect of Microstructure on HIC Susceptibility of API X70MS Linepipe Steel

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Joon-Ho; Sim, Ho-Seop; Park, Byung-Gyu [Dongkuk Steel R and D Center, Pohang (Korea, Republic of); Cho, Kyung-Mox [Pusan National University, Busan (Korea, Republic of)


    The resistance of hydrogen induced cracking (HIC) was investigated with different microstructures of API X70MS steel. Ferrite/acicular ferrite (F/AF), deformed ferrite/acicular ferrite, ferrite/bainite (F/B) and single acicular ferrite (AF) were obtained by thermo-mechanical controlled process (TMCP) with changing rolling and cooling conditions. HIC resistance was found to be affected by the type as well as morphology of the microstructure, and thus the behavior of crack initiation and propagation could be analyzed. It was found that single AF and deformed F/AF with uniformly distributed dislocation reduced HIC initiation. Banded microstructure with a hardness value below 250 HV, such as AF, showed good HIC propagation resistance due to high toughness. AF generally exhibited excellent crack initiation and propagation resistance, namely the best HIC susceptibility performance. AF might redeem the HIC resistance for the banded microstructure also.

  3. 49 CFR 195.230 - Welds: Repair or removal of defects. (United States)


    ... offshore pipeline being installed from a pipelay vessel, a weld must be removed if it has a crack that is... must be inspected to ensure its acceptability. (c) Repair of a crack, or of any defect in a previously... welding procedure used to make the original weld are met upon completion of the final weld repair. [Amdt...

  4. Northern pipelines : challenges and needs

    Energy Technology Data Exchange (ETDEWEB)

    Dean, D.; Brownie, D. [ProLog Canada Inc., Calgary, AB (Canada); Fafara, R. [TransCanada PipeLines Ltd., Calgary, AB (Canada)


    Working Group 10 presented experiences acquired from the operation of pipeline systems in a northern environment. There are currently 3 pipelines operating north of 60, notably the Shiha gas pipeline near Fort Liard, the Ikhil gas pipeline in Inuvik and the Norman Wells oil pipeline. Each has its unique commissioning, operating and maintenance challenges, as well as specific training and logistical support requirements for the use of in-line inspection tools and other forms of integrity assessment. The effectiveness of cathodic protection systems in a permafrost northern environment was also discussed. It was noted that the delay of the Mackenzie Gas Pipeline Project by two to three years due to joint regulatory review may lead to resource constraints for the project as well as competition for already scarce human resources. The issue of a potential timing conflict with the Alaskan Pipeline Project was also addressed as well as land use issues for routing of supply roads. Integrity monitoring and assessment issues were outlined with reference to pipe soil interaction monitoring in discontinuous permafrost; south facing denuded slope stability; base lining projects; and reclamation issues. It was noted that automatic welding and inspection will increase productivity, while reducing the need for manual labour. In response to anticipated training needs, companies are planning to involve and train Aboriginal labour and will provide camp living conditions that will attract labour. tabs., figs.

  5. Leadership Pipeline

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård


    Artiklen analyserer grundlaget for Leadership Pipeline modellen med henblik på en vurdering af substansen bag modellen, og perspektiverne for generalisering af modellen til en dansk organisatorisk kontekst.......Artiklen analyserer grundlaget for Leadership Pipeline modellen med henblik på en vurdering af substansen bag modellen, og perspektiverne for generalisering af modellen til en dansk organisatorisk kontekst....


    Energy Technology Data Exchange (ETDEWEB)

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan


    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  7. Welding Curriculum. (United States)

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum guide is a handbook for the development of welding trade programs. Based on a survey of Alaskan welding employers, it includes all competencies a student should acquire in such a welding program. The handbook stresses the importance of understanding the principles associated with the various elements of welding.…



    Marcos Theodoro Muller; Rafael Rodolfo de Melo; Diego Martins Stangerlin


    The term "wood welding" designates what can be defined as "welding of wood surfaces". This new process, that it provides the joint of wood pieces without the use of adhesives or any other additional material, provokes growing interest in the academic environment, although it is still in laboratorial state. Linear friction welding induced bymechanical vibration yields welded joints of flat wood surfaces. The phenomenon of the welding occurs in less time than 10 seconds, with the temperature in...

  9. Advanced Welding Concepts (United States)

    Ding, Robert J.


    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.


    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary


    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners


    Energy Technology Data Exchange (ETDEWEB)

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary


    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  12. Resistance welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.


    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has changed...

  13. X 100 welding technology - past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Marie [Lincoln Electric, Cleveland, OH, (United States); Hammond, John [Consultant Mettalurgist and Welding Enginner, Helfordshire, (United Kingdom)


    The X100 steel pipeline has been widely studied in the last decade. The welding process remains a major concern. This paper presents a review of the X100 welding technology literature. It summarizes the current state of the art regarding welding technology (manual, semi-automatic and mechanized) applied to X100 pipeline construction. The following aspects are developed: a synopsis of experience to date, a description of the current status and the pending developments in welding processes and consumables, an assessment of first and second level contractor capability and, to summarize, a review of the key knowledge and experience gaps. It appears that the modern X100 line pipe has been largely improved lately. The X100 pipeline reached the ISO, API and CSA requirements which is a first step to standardization. The development of main-line girth welding of X100 has been successful.

  14. Leadership Pipeline

    DEFF Research Database (Denmark)

    Elmholdt, Claus Westergård


    I artiklen undersøges det empiriske grundlag for Leader- ship Pipeline. Først beskrives Leadership Pipeline modellen om le- delsesbaner og skilleveje i opadgående transitioner mellem orga- nisatoriske ledelsesniveauer (Freedman, 1998; Charan, Drotter and Noel, 2001). Dernæst sættes fokus på det...... forholdet mellem kontinuitet- og diskontinuitet i ledel- seskompetencer på tværs af organisatoriske niveauer præsenteres og diskuteres. Afslutningsvis diskuteres begrænsningerne i en kompetencebaseret tilgang til Leadership Pipeline, og det foreslås, at succesfuld ledelse i ligeså høj grad afhænger af...

  15. 5. symposium of pipeline technology. Proceedings; 5. Symposium Pipelinetechnik. Vortraege

    Energy Technology Data Exchange (ETDEWEB)



    Innovations in the technical systems of rules for pipelines. Data and speech transmission at pipelines via light wiring. Dynamic leak detection and localisation. Future integrity as part of the total pipeline integrity. Assessment of pipeline flaws using the European SINTAP procedure. Automatic registration of alternating pressure loads. Rehabilitation of a crude oil pipeline. Online Inspektion von ''Non-piggable pipelines''. New technologies for the inspection of longitudinal welds and longitudinal oriented defects in pipelines. Construction of intelligent pigs with regard to the assessment of defects in pipelines. (orig./GL) [German] Aus dem Inhalt: Neuerungen im technischen Regelwerk fuer Fernleitungen. Daten- und Sprachuebertragung an Fernleitungen ueber Lichtwellenleiter. Dynamische Leckerkennung und -ortung. Future intergrity as part of the total pipeline integrity. Fehlerstellenbewertung an einer Pipeline durch Anwendung des SINTAP-Verfahrens. Automatische Lastwechselerfassung. Sanierung einer Rohoelpipeline. Online Inspektion von ''Non-piggable pipelines''. Neue Technologien im Bereich der Inspektion von Laengsnaehten und laengsorientierten Fehlern in Pipelines. Neubau von intelligenten Molchen unter dem Aspekt der Bewertung von Fehlern in Pipelines. (orig./GL)

  16. Welding Technician (United States)

    Smith, Ken


    About 95% of all manufactured goods in this country are welded or joined in some way. These welded products range in nature from bicycle handlebars and skyscrapers to bridges and race cars. The author discusses what students need to know about careers for welding technicians--wages, responsibilities, skills needed, career advancement…

  17. Weld microstructure and hardness prediction for in-service hot-tap welds

    Energy Technology Data Exchange (ETDEWEB)

    Wentao Cheng; Yong-Yi Wang [Engineering Mechanics Corporation of Columbus, OH (United States)]. E-mail:;; Amend, William [Southern California Gas Co., Los Angeles, CA (United States)]. E-mail:


    Welding onto an in-service pipeline is frequently required to repair damaged areas and for system modifications. There are often significant economic and environmental incentives to perform in-service welding, including the ability to maintain operations during welding and to avoid venting the contents to the atmosphere. Welds made onto in-service pipelines tend to cool at an accelerated rate. These welds are likely to have high heat-affected zone (HAZ) hardness which increases their susceptibility to hydrogen cracking. Accurate prediction of HAZ hardness is critical in developing successful welding procedures for in-service hot-tap welds. The present PRCI thermal analysis software for hot-tap welding uses an empirical-formula-based HAZ hardness prediction procedure. This paper describes an effort funded by PRCI to produce a significantly improved HAZ hardness prediction procedure over the procedure in the current PRCI thermal analysis software. A markedly improved hardness prediction procedure was developed and systematically validated using extensive experimental data of actual welds. The underlying hardness calculation algorithms were based on the proven state-of-the-art phase transformation models. Although on the average the procedure under-predicts the measured hardness by a small amount, the new hardness prediction procedure is a significant improvement in overall accuracy over the procedure in the current PRCI thermal analysis software. The procedure developed here lays the foundation for a much more accurate hardness prediction module in the future version of the PRCI thermal analysis software. (author)

  18. The Effect of Cathodic Protection on Stress Corrosion Cracking of High-Strength Pipeline Steels, #350 (United States)


    The objective of this study was to establish the effect of cathodic protection (CP) to produce hydrogen that can cause cracking and in-service failures of high-strength pipeline steels, from X-70 to X-120, and to establish the effectiveness of cathod...

  19. Pipeline Power


    Hubert, Franz; Cobanli, Onur


    We use cooperative game theory to analyze the impact of three controversial pipeline projects on the power structure in the Eurasian trade of natural gas. Two of them, Nord Stream and South Stream, allow Russian gas to bypass transit countries, Ukraine and Belarus. Nord Stream’s strategic value turns out to be huge, justifying the high investment cost for Germany and Russia. The additional leverage obtained through South Stream, in contrast, appears small. The third project, Nabucco, aims at ...

  20. Survey of welding processes. (United States)


    The current KYTC SPECIAL PROVISION NO. 4 WELDING STEEL BRIDGES prohibits the use of welding processes other than shielded metal arc welding (SMAW) and submerged arc welding (SAW). Nationally, bridge welding is codified under ANSI/AASHTO/AWS D1....

  1. Soldadura (Welding). Spanish Translations for Welding. (United States)

    Hohhertz, Durwin

    Thirty transparency masters with Spanish subtitles for key words are provided for a welding/general mechanical repair course. The transparency masters are on such topics as oxyacetylene welding; oxyacetylene welding equipment; welding safety; different types of welds; braze welding; cutting torches; cutting with a torch; protective equipment; arc…

  2. WELDING TORCH (United States)

    Correy, T.B.


    A welding torch into which water and inert gas are piped separately for cooling and for providing a suitable gaseous atmosphere is described. A welding electrode is clamped in the torch by a removable collet sleeve and a removable collet head. Replacement of the sleeve and head with larger or smaller sleeve and head permits a larger or smaller welding electrode to be substituted on the torch. (AEC)

  3. Practical significance of weld strength matching

    Energy Technology Data Exchange (ETDEWEB)

    Sloterdijk, W. [N.V. Nederlandse Gasunie, Groningen (Netherlands); Schipaanboord, W.N. [N.V. Nederlandse Gasunie, Groningen (Netherlands)


    Defect tolerance in welds in pipelines constructed in modern high strength material depends on the balance in strength between weld material and pipe material. The Guidelines on the assessment of girth weld defects published by the European Pipeline Research Group (EPRG) define in Tier 2 defect limits assuming that the (actual) weld metal yield strength is equal or greater than the yield strength of the parent material. The defect limits according to Tier 2 exceed the defect limits in `workmanship standards` (l>25 mm). Nevertheless, the draft European welding standard EN 288 does not yet require a test to measure and verify the weld metal yield strength. Gasunie has performed a test program with the aim to look at the practical significance of weld strength matching in a strain controlled situation and to verify the relevance of limits given in the European welding and line pipe codes, in combination with the EPRG Guidelines. It is concluded that the results of the tests confirm the defect acceptance limits according to Tier 2 of the EPRG Guidelines. (orig.) [Deutsch] Die Zulaessigkeit von Fehlern in Rundschweissnaehten in Rohrleitungen aus modernen hochfesten Baustaehlen haengt von dem Verhaeltnis der Werkstofffestigkeit des Schweissgutes zu der des Grundwerkstoffs ab. Die von der European Pipeline Research Group (EPRG) veroeffentlichte Richtlinie zur Bewertung von Schweissnahtfehlern gibt in der zweiten Bewertungsstufe (Tier 2) Werte fuer zulaessige Schweissnahtfehlergroessen unter der Bedingung an, dass die Dehngrenze des Schweissgutes groesser oder gleich der Dehngrenze des Grundwerkstoffs ist. Die nach Tier 2 zulaessigen Fehler sind groesser als die in `Good-workmanship`-Regelwerken angegebenen Fehlerlaenge (l>25 mm). Demgegenueber fehlt im Entwurf der europaeischen Schweissnorm EN 288 bislang ein solcher Dehngrenzennachweis. Gasunie hat ein Versuchsprogramm durchgefuehrt, um die Bedeutung der Schweissgutfestigkeit bei dehnungskontrollierter Belastung sowie

  4. Experimental squash load of concrete-filled thin welded cold formed ...

    African Journals Online (AJOL)

    concrete stubs are presented. The stub section was made from two U shaped cold formed steel plates welded to form box whose dimensions were: 100x70x2mm. The main parameters studied were: stub height (50-500mm), effect of the concrete ...

  5. Necessary calorific energy during the in-service welding of pipelines for petroleum transport; Energia calorifica necesaria durante la soldadura en servicio de tuberias para el transporte de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Morales, Felix; Scott, Alejandro Duffus; Rodriguez Perez, Manuel; Diza Cedre, Eduardo; Pozo Morejon, Juan A. [Universidad Central Marta Abreu de las Villas, Santa Clara, Villa Clara (Cuba). Centro de Investigaciones de Soldadura


    The thermal behavior during in service repair welding of oil transportation pipes was studied by finite element analysis in the present paper. Regression equations that relate peak temperature at the inner surface of the pipe and cooling time between 800 and 500 deg C in the heat affected zone to the welding heat input, preheat temperature, and convection heat transfer coefficient were obtained. The former parameters govern, respectively, the possibility of burn through and cold cracking, and the latter parameters define the thermal behavior during welding. The existence of conditions that simultaneously satisfy the obtained equations, for different combinations of related variables, was proved. Graphical representations of relevant practical importance that were developed from the solution of obtained equations are presented. (author)

  6. Plasma arc welding weld imaging (United States)

    Rybicki, Daniel J. (Inventor); Mcgee, William F. (Inventor)


    A welding torch for plasma arc welding apparatus has a transparent shield cup disposed about the constricting nozzle, the cup including a small outwardly extending polished lip. A guide tube extends externally of the torch and has a free end adjacent to the lip. First and second optical fiber bundle assemblies are supported within the guide tube. Light from a strobe light is transmitted along one of the assemblies to the free end and through the lip onto the weld site. A lens is positioned in the guide tube adjacent to the second assembly and focuses images of the weld site onto the end of the fiber bundle of the second assembly and these images are transmitted along the second assembly to a video camera so that the weld site may be viewed continuously for monitoring the welding process.

  7. WELDING METHOD (United States)

    Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.


    A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

  8. Causes of the cracks in the pipeline made of the 15HM steel

    Directory of Open Access Journals (Sweden)

    Słania J.


    Full Text Available Issues referring to cracks in the pipelines made of the 15HM steel are described. Metallographic specimen of welded joints are provided. The results of impact strength tests, hardness tests and static tensile tests are given. Tests results as well as direct and indirect causes of the pipeline cracks are shown.

  9. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark


    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  10. 30 CFR 56.4604 - Preparation of pipelines or containers. (United States)


    ... Section 56.4604 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 56.4604 Preparation of pipelines or containers...

  11. 30 CFR 57.4604 - Preparation of pipelines or containers. (United States)


    ... Section 57.4604 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Welding/cutting/compressed Gases § 57.4604 Preparation of pipelines or containers...

  12. Failure analysis of oil pipelines | Ajayi | Botswana Journal of ...

    African Journals Online (AJOL)

    ... the crude, but had a rather low fatigue strength (46.10N/mm2) when compared to the standard. It is suggested that welded joints in pipes be heat-treated and coated on clean substrate pipe in order to enhance material integrity in service. Keywords: Failure Analysis, Oil Pipeline, Corrosion, Environment, Photomicrograph ...

  13. Syllabus in Trade Welding. (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The syllabus outlines material for a course two academic years in length (minimum two and one-half hours daily experience) leading to entry-level occupational ability in several welding trade areas. Fourteen units covering are welding, gas welding, oxyacetylene welding, cutting, nonfusion processes, inert gas shielded-arc welding, welding cast…

  14. A novel approach to pipeline tensioner modeling

    Energy Technology Data Exchange (ETDEWEB)

    O' Grady, Robert; Ilie, Daniel; Lane, Michael [MCS Software Division, Galway (Ireland)


    As subsea pipeline developments continue to move into deep and ultra-deep water locations, there is an increasing need for the accurate prediction of expected pipeline fatigue life. A significant factor that must be considered as part of this process is the fatigue damage sustained by the pipeline during installation. The magnitude of this installation-related damage is governed by a number of different agents, one of which is the dynamic behavior of the tensioner systems during pipe-laying operations. There are a variety of traditional finite element methods for representing dynamic tensioner behavior. These existing methods, while basic in nature, have been proven to provide adequate forecasts in terms of the dynamic variation in typical installation parameters such as top tension and sagbend/overbend strain. However due to the simplicity of these current approaches, some of them tend to over-estimate the frequency of tensioner pay out/in under dynamic loading. This excessive level of pay out/in motion results in the prediction of additional stress cycles at certain roller beds, which in turn leads to the prediction of unrealistic fatigue damage to the pipeline. This unwarranted fatigue damage then equates to an over-conservative value for the accumulated damage experienced by a pipeline weld during installation, and so leads to a reduction in the estimated fatigue life for the pipeline. This paper describes a novel approach to tensioner modeling which allows for greater control over the velocity of dynamic tensioner pay out/in and so provides a more accurate estimation of fatigue damage experienced by the pipeline during installation. The paper reports on a case study, as outlined in the proceeding section, in which a comparison is made between results from this new tensioner model and from a more conventional approach. The comparison considers typical installation parameters as well as an in-depth look at the predicted fatigue damage for the two methods

  15. Development of Heat-Affected Zone Hardness Limits for In-Service Welding (United States)


    Welding onto in-service pipelines is frequently required to facilitate a repair or to install a branch connection using the "hot tapping" technique. Welds made in-service cool at an accelerated rate as the result of the ability of the flowing content...

  16. Development of an automatic pipeline scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae H.; Lee, Jae C.; Moon, Soon S.; Eom, Heung S.; Choi, Yu R


    Pressure pipe inspection in nuclear power plants is one of the mandatory regulation items. Comparing to manual ultrasonic inspection, automatic inspection has the benefits of more accurate and reliable inspection results and reduction of radiation disposal. final object of this project is to develop an automatic pipeline inspection system of pressure pipe welds in nuclear power plants. We developed a pipeline scanning robot with four magnetic wheels and 2-axis manipulator for controlling ultrasonic transducers, and developed the robot control computer which controls the robot to navigate along inspection path exactly. We expect our system can contribute to reduction of inspection time, performance enhancement, and effective management of inspection results. The system developed by this project can be practically used for inspection works after field tests. (author)

  17. Distortion Control during Welding


    Akbari Pazooki, A.M.


    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ methods to control welding distortion. In these methods local heating and/or cooling strategies are applied during welding. Additional heating and/or cooling sources can be implemented either stationa...

  18. WELDING PROCESS (United States)

    Zambrow, J.; Hausner, H.


    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  19. Welding processes handbook

    CERN Document Server

    Weman, Klas


    Offers an introduction to the range of available welding technologies. This title includes chapters on individual techniques that cover principles, equipment, consumables and key quality issues. It includes material on such topics as the basics of electricity in welding, arc physics, and distortion, and the weldability of particular metals.$bThe first edition of Welding processes handbook established itself as a standard introduction and guide to the main welding technologies and their applications. This new edition has been substantially revised and extended to reflect the latest developments. After an initial introduction, the book first reviews gas welding before discussing the fundamentals of arc welding, including arc physics and power sources. It then discusses the range of arc welding techniques including TIG, plasma, MIG/MAG, MMA and submerged arc welding. Further chapters cover a range of other important welding technologies such as resistance and laser welding, as well as the use of welding techniqu...

  20. Friction Stir Welding (United States)

    Nunes, Arthur C., Jr.


    Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

  1. BPC Trenchless Pipeline System

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Martin


    The BPC trenchless system features pipeline installation through directional drilling utilizing horizontal directional boring along with state of the art mapping and product coating integrity surveys after pipe placement. The trenchless system developed by BPC reduces environmental disturbances, with savings in reclaiming pipeline right-of-ways such as re-seeding and contouring. It is felt that with smaller pipelines of less than 1,000 metres, a reduction in environmental footprint is now technically feasible using this technology.

  2. Mechanical properties of API X80 steel pipe joints welded by Flux Core Arc Weld Process; Propriedades mecanicas de juntas de tubos de aco API X80 soldadas com arame tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez, Robert E. Cooper; Silva, Jose Hilton F.; Trevisan, Roseana E. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Engenharia de Fabricacao


    Flux Core Arc Welding processes (FCAW) are beginning to be applied in pipeline welds, however, very limited experimental data regarding mechanical properties of pipeline weld joints with these processes are available in the literature. In this paper, the effects of preheat temperature and type of FCAW on mechanical properties (microhardness and tensile strength) of API X80 weld joint steel are presented. FCAW processes with gas protection and self-shielded were used. Multipasses welding were applied in 30'' diameter and 0,625'' thickness tubes. Influence factors were: FCAW type and preheat temperature. Acceptance criteria of welded joints were evaluated by API 1104 standard for tensile strength test and ASTM E384-99 for microhardness test. The results obtained showed that FCAW type and preheat temperature have no influence on mechanical properties of API X80 joint steel. (author)

  3. Introduction to Welding. (United States)

    Fortney, Clarence; Gregory, Mike

    This curriculum guide provides six units of instruction on basic welding. Addressed in the individual units of instruction are the following topics: employment opportunities for welders, welding safety and first aid, welding tools and equipment, basic metals and metallurgy, basic math and measuring, and procedures for applying for a welding job.…

  4. Distortion Control during Welding

    NARCIS (Netherlands)

    Akbari Pazooki, A.M.


    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ

  5. Pipeline system operability review

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Kjell [Det Norske Veritas (Norway); Davies, Ray [CC Technologies, Dublin, OH (United States)


    Pipeline operators are continuously working to improve the safety of their systems and operations. In the US both liquid and gas pipeline operators have worked with the regulators over many years to develop more systematic approaches to pipeline integrity management. To successfully manage pipeline integrity, vast amounts of data from different sources needs to be collected, overlaid and analyzed in order to assess the current condition and predict future degradation. The efforts undertaken by the operators has had a significant impact on pipeline safety, nevertheless, during recent years we have seen a number of major high profile accidents. One can therefore ask how effective the pipeline integrity management systems and processes are. This paper will present one methodology 'The Pipeline System Operability Review' that can evaluate and rate the effectiveness of both the management systems and procedures, as well as the technical condition of the hardware. The result from the review can be used to compare the performance of different pipelines within one operating company, as well as benchmark with international best practices. (author)

  6. Advanced Welding Applications (United States)

    Ding, Robert J.


    Some of the applications of advanced welding techniques are shown in this poster presentation. Included are brief explanations of the use on the Ares I and Ares V launch vehicle and on the Space Shuttle Launch vehicle. Also included are microstructural views from four advanced welding techniques: Variable Polarity Plasma Arc (VPPA) weld (fusion), self-reacting friction stir welding (SR-FSW), conventional FSW, and Tube Socket Weld (TSW) on aluminum.

  7. Slurry pipeline hydrostatic testing

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy G.; Navarro Rojas, Luis Alejandro [BRASS Chile S.A., Santiago (Chile)


    The transportation of concentrates and tailings through long distance pipeline has been proven in recent years to be the most economic, environmentally friendly and secure means of transporting of mine products. This success has led to an increase in the demand for long distance pipeline throughout the mining industry. In year 2007 alone, a total of over 500 km of pipeline has been installed in South America alone and over 800 km are in the planning stages. As more pipelines are being installed, the need to ensure its operating integrity is ever increasing. Hydrostatic testing of long distance pipeline is one of the most economical and expeditious way to proving the operational integrity of the pipe. The intent of this paper is to show the sound reasoning behind construction hydro testing and the economic benefit it presents. It will show how hydro test pressures are determined based on ASME B31.11 criteria. (author)

  8. Slurry pipeline design approach

    Energy Technology Data Exchange (ETDEWEB)

    Betinol, Roy; Navarro R, Luis [Brass Chile S.A., Santiago (Chile)


    Compared to other engineering technologies, the design of a commercial long distance Slurry Pipeline design is a relatively new engineering concept which gained more recognition in the mid 1960 's. Slurry pipeline was first introduced to reduce cost in transporting coal to power generating units. Since then this technology has caught-up worldwide to transport other minerals such as limestone, copper, zinc and iron. In South America, the use of pipeline is commonly practiced in the transport of Copper (Chile, Peru and Argentina), Iron (Chile and Brazil), Zinc (Peru) and Bauxite (Brazil). As more mining operations expand and new mine facilities are opened, the design of the long distance slurry pipeline will continuously present a commercially viable option. The intent of this paper is to present the design process and discuss any new techniques and approach used today to ensure a better, safer and economical slurry pipeline. (author)

  9. Failure Analysis of X80 Line Pipe’s Circumferential Weld

    Directory of Open Access Journals (Sweden)

    Liu Hong Liang


    Full Text Available One 530mm X80 pipeline weld failed infrequently in service process. This paper gives a systematic analysis in consideration of both material quality and loading condition. Inspection was performed on chemical composition, mechanical performance, metallograghy and micro-morphology. The result shows that weld joint’s leakage failure accident is fatigue failure. Under the effect of tensile- tensile stress fatigue stress, fatigue crack originated from weld fusion line near the pipe body and developed along the weld. Porosity defect in the weld reduced its bearing capacity, and promoted the formation and development of the fatigue crack. Fatigue strength and fatigue life of the weld has great relationship with the size and distribution of porosity. The greater the porosity, the more close to surface, the decrease of fatigue life is more obvious.

  10. Central oxygen pipeline failure

    African Journals Online (AJOL)

    the newly replaced main oxygen valve was slowly opened to allow pipeline pressure to build. ... The gas then passes through high-pressure regulators, which regulate the ... 1Department of Anaesthesiology and Sedation & Pain control, UWC.

  11. Chechnya: the pipeline front

    Energy Technology Data Exchange (ETDEWEB)



    This article examines the impact of the Russian campaign against Chechnya on projects for oil and gas pipelines from the new Caspian republics, which are seeking financial support. Topics discussed include the pipeline transport of oil from Azerbaijan through Chechnya to the Black Sea, the use of oil money to finance the war, the push for non-Russian export routes, the financing of pipelines, the impact of the war on the supply of Russian and Turkmenistan gas to Turkey, the proposed construction of the Trans Caspian pipeline, the weakening of trust between Russia and its neighbours, and the potential for trans Caucasus republics to look to western backers due to the instability of the North Caucasus. (UK)

  12. Reprocessing weld and method

    Energy Technology Data Exchange (ETDEWEB)

    Killian, M.L.; Lewis, H.E.


    A process is described for improving the fatigue resistance of a small primary structural weld at a joint between structural members of a weldment, the weld having been made with the welding energy input of E[sub 1], the process comprising: applying a reprocessing weld on at least a portion of either one or both toes of the primary structural weld, thereby covering said toe portion, the reprocessing weld containing a filler metal and having a cross-sectional area which is less than the corresponding cross-sectional area of the primary structural weld, the reprocessing weld extending onto the face of the primary structural weld at one side of the toe portion covered and onto the structural member at the other side of the toe portion covered, and the total welding energy input, E[sub 2], used in said reprocessing the primary structural weld being less than the welding energy input E[sub 1] of the primary structural weld.

  13. Novel Optimization Methodology for Welding Process/Consumable Integration

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, Marie A; DebRoy, Tarasankar; Vitek, John; Babu, Suresh


    Advanced materials are being developed to improve the energy efficiency of many industries of future including steel, mining, and chemical, as well as, US infrastructures including bridges, pipelines and buildings. Effective deployment of these materials is highly dependent upon the development of arc welding technology. Traditional welding technology development is slow and often involves expensive and time-consuming trial and error experimentation. The reason for this is the lack of useful predictive tools that enable welding technology development to keep pace with the deployment of new materials in various industrial sectors. Literature reviews showed two kinds of modeling activities. Academic and national laboratory efforts focus on developing integrated weld process models by employing the detailed scientific methodologies. However, these models are cumbersome and not easy to use. Therefore, these scientific models have limited application in real-world industrial conditions. On the other hand, industrial users have relied on simple predictive models based on analytical and empirical equations to drive their product development. The scopes of these simple models are limited. In this research, attempts were made to bridge this gap and provide the industry with a computational tool that combines the advantages of both approaches. This research resulted in the development of predictive tools which facilitate the development of optimized welding processes and consumables. The work demonstrated that it is possible to develop hybrid integrated models for relating the weld metal composition and process parameters to the performance of welds. In addition, these tools can be deployed for industrial users through user friendly graphical interface. In principle, the welding industry users can use these modular tools to guide their welding process parameter and consumable composition selection. It is hypothesized that by expanding these tools throughout welding industry

  14. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

  15. Welding Course Curriculum. (United States)

    Genits, Joseph C.

    This guide is intended for use in helping students gain a fundamental background on the major aspects of the welding trade. The course emphasis is on mastery of the manipulative skills necessary to develop successful welding techniques and on acquisition of an understanding of the specialized tools and equipment used in welding. The first part…

  16. Instructional Guidelines. Welding. (United States)

    Fordyce, H. L.; Doshier, Dale

    Using the standards of the American Welding Society and the American Society of Mechanical Engineers, this welding instructional guidelines manual presents a course of study in accordance with the current practices in industry. Intended for use in welding programs now practiced within the Federal Prison System, the phases of the program are…

  17. Modeling of plasma and thermo-fluid transport in hybrid welding (United States)

    Ribic, Brandon D.

    Hybrid welding combines a laser beam and electrical arc in order to join metals within a single pass at welding speeds on the order of 1 m min -1. Neither autonomous laser nor arc welding can achieve the weld geometry obtained from hybrid welding for the same process parameters. Depending upon the process parameters, hybrid weld depth and width can each be on the order of 5 mm. The ability to produce a wide weld bead increases gap tolerance for square joints which can reduce machining costs and joint fitting difficulty. The weld geometry and fast welding speed of hybrid welding make it a good choice for application in ship, pipeline, and aerospace welding. Heat transfer and fluid flow influence weld metal mixing, cooling rates, and weld bead geometry. Cooling rate affects weld microstructure and subsequent weld mechanical properties. Fluid flow and heat transfer in the liquid weld pool are affected by laser and arc energy absorption. The laser and arc generate plasmas which can influence arc and laser energy absorption. Metal vapors introduced from the keyhole, a vapor filled cavity formed near the laser focal point, influence arc plasma light emission and energy absorption. However, hybrid welding plasma properties near the opening of the keyhole are not known nor is the influence of arc power and heat source separation understood. A sound understanding of these processes is important to consistently achieving sound weldments. By varying process parameters during welding, it is possible to better understand their influence on temperature profiles, weld metal mixing, cooling rates, and plasma properties. The current literature has shown that important process parameters for hybrid welding include: arc power, laser power, and heat source separation distance. However, their influence on weld temperatures, fluid flow, cooling rates, and plasma properties are not well understood. Modeling has shown to be a successful means of better understanding the influence of

  18. Calculation of the technological parameters of electrofusion welding of polyethylene pipes at low temperatures (United States)

    Starostin, N. P.; Ammosova, O. A.


    The thermal process of electrofusion welding of polyethylene gas pipelines at air temperatures below the standard is investigated. The mathematical model used in the research takes into account the heat of the phase transition in the temperature interval. Computational experiments show the possibility of regulating the temperature regime for welding at low ambient air temperatures and providing the same temperature field variation in the thermal zone as with the permissible air temperatures.

  19. Offshore pipelines in cold regions : environmental loadings and geotechnical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Paulin, M.J.; Caines, J. [IMV Projects Atlantic, St. John' s, NL (Canada); Kenny, S.P. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada). Dept. of Engineering and Applied Science; Palmer, A.C. [National Univ. of Singapore, Queenstown, (Singapore). Dept. of Civil Engineering; Been, K. [Golder Associates Inc., Houston, TX (United States)


    As a result of the industry's continued search for oil and gas in frontier offshore locations, several developments have occurred in areas characterized by seasonal ice cover including the United States Beaufort, North Caspian, and Sakhalin Island. Pipeline transportation systems have been utilized as a cost-effective, safe and reliable mode of hydrocarbon transport to shore in these projects. However, ice gouging is a primary design issue that affects engineering considerations with respect to strain based design, target burial depth requirements, cost and safety. This paper discussed environmental loadings and geotechnical considerations with respect to offshore pipelines in cold regions. The paper discussed data collection needs such as ice gouge data specific to the pipeline route, and information on sediment transport to determine burial depths for a given ice gouge environment. Ice gouging was also defined in terms of subgouge soil deformations and gouge depth from gouge survey observations. Last, the paper addressed modeling coupled ice keel/seabed/pipeline interaction, trenching and backfilling, and implications for pipeline design and construction. It was concluded that evaluation of the system demand and system capacity influence engineering design considerations that may impact the construction and operational phases. Important issues include material selection; linepipe qualification; welding procedures; limit state criteria for strain based design; leak detection; condition monitoring systems and in-line inspection tools. 34 refs., 10 figs.

  20. Comportamiento a la Corrosión del Acero API X70 Soldado por el Proceso de Doble Arco Sumergido Inmerso en Diferentes Medios Corrosivos

    Directory of Open Access Journals (Sweden)

    Omar Francisco Montes

    Full Text Available Resumen Los aceros API X70 son aplicados en fabricación y construcción de tuberías para el transporte de hidrocarburos, sin embargo, a un lapso de tiempo se degradan debido al medio ambiente al cual están expuestos; influyendo en la velocidad y tipo de corrosión sobre las superficies del metal base (MB, zona afectada por el calor (ZAC y zona de fusión (ZF. A fin de conocer y evaluar la susceptibilidad a la corrosión en uniones del acero API X70 sometido a diferentes medios corrosivos, varias pruebas se llevaron a cabo por el proceso de soldadura de doble arco sumergido (DSAW, por sus siglas en inglés, las cuales fueron inmersas en diferentes electrolitos: Cloruro de Sodio (NaCl al 3,5% y Agua (H2O a temperatura ambiente para conocer su comportamiento. Se utilizaron técnicas electroquímicas de ruido electroquímico (RE y curvas de polarización cíclica (CPC para obtener velocidad y tipo de corrosión producida en cada una de las muestras analizadas, incluyendo las tres zonas: MB, ZAC y ZF. Además, se utilizaron técnicas de caracterización como microscopía óptica (MO y microscopía electrónica de barrido (MEB para el análisis superficial. La mayoría de las soldaduras presentan corrosión mixta, con mayores velocidades de corrosión en 3,5% de NaCl.

  1. 75 FR 13342 - Pipeline Safety: Workshop on Distribution Pipeline Construction (United States)


    ... practices. (3) Construction Issues, Joining, Horizontal Directional Drill/ Boring, Excavation Damage. (4... Construction AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: Notice of... Safety Representatives (NAPSR) on new distribution pipeline construction. The workshop will allow...

  2. Physics of arc welding (United States)

    Eagar, T. W.


    A discussion of the factors controlling the size and shape of the weld fusion zone is presented along with a description of current theories of heat and fluid flow phenomena in the plasma and the molten metal weld pool. Although experimental results confirm that surface tension, plasma jets, and weld pool convection all strongly influence the fusion zone shape; no comprehensive model is available from which to predict welding behavior. It is proposed that the lack of such an understanding is a major impediment to development of automated welding processes. In addition, sensors for weld torch positioning are reviewed in terms of the mechnical and electromagnetic energy spectra which have been used. New developments in this area are also needed in order to advance the technology of automated welding.

  3. Dual wire weld feed proportioner (United States)

    Nugent, R. E.


    Dual feed mechanism enables proportioning of two different weld feed wires during automated TIG welding to produce a weld alloy deposit of the desired composition. The wires are fed into the weld simultaneously. The relative feed rates of the wires and the wire diameters determine the weld deposit composition.

  4. Stress analysis of a large diameter, heated pipeline in mountainous terrain

    Energy Technology Data Exchange (ETDEWEB)

    Arevalo, Dario R.; Riccillo, Domingo; Curle, Ronald K. [TECHINT S.A. (Brazil)


    The primary goals of modern pipeline design and construction projects, are safety and low cost. High strength steels such as API-5L Gr. X70 reduce installed weights but translate into high D/t ratios. Modern manufacturing methods, used produce API grade pipes, increase yield strength with minimal changes to the ultimate tensile strength (UTS). The trend toward the use of high strength pipe reduces costs, but correspondingly increases D/t ratios. There are significant challenges in stress and rupture analysis to ensure stability under loading conditions that include static and transient pressures, high temperatures, dead weights, and seismic forces. (author)

  5. Central oxygen pipeline failure

    African Journals Online (AJOL)

    was welding in the presence of an unidentified oxygen leak, which caused an explosion and the subsequent failure of the main oxygen valve. This happened while I was on duty in the surgical intensive care unit (ICU), with two patients on full ventilation and four patients breathing spontaneously on 40% oxygen face masks.

  6. Nearshore Pipeline Installation Methods. (United States)


    After welding, this uncoated area must be wire brush cleaned, primed, and coated with materials compatible with the coating previously applied. It is...from 20 feet to over 1000 teet , and in a wide variety of weather conditions. b) If a pipe failure occurs during laying, the lay barge can, in most cases

  7. Wave propagation versus transient ground displacement as a credible hazard to buried oil and gas pipelines

    Energy Technology Data Exchange (ETDEWEB)



    The cause of damage to a natural gas pipeline during the 1994 Northridge earthquake in the San Fernando Valley in California was examined in a collaborative effort by Southern California Gas Co., Pacific Gas and Electric Co., and with support from Tokyo Gas, Osaka Gas and Toho Gas. Extensive field and laboratory studies were conducted on a 1925 gas pipeline that suffered several girth weld failures in Potrero Canyon where significant ground displacement was observed. Ground cracking and sand boils were observed in the area following the earthquake but there were few other signs of permanent ground deformation near the pipeline damage. Damage consisted mostly of girth weld tensile failure and two cases of buckling of the pipe wall. Initial evidence suggested that the damage may have been caused by wave propagation, but a detailed study has shown that wave propagation effect was not a significant factor in the pipeline damage. A simple analytical model was developed to determine the transient ground deformation that might have occurred in the area of the pipeline damage. The model also provides clues regarding the cause of the ground cracking observed at the margins of the canyon. It also provides approximate magnitudes of differential ground displacements resulting from the earthquake. The model also considers the reasons for spatial distribution of pipeline damage. 13 refs., 1 tab., 6 figs.

  8. Anti-Thixotropic Analysis of Pipeline Metal Losses in Welded ...

    African Journals Online (AJOL)

    This investigation was verified by measuring the metal losses using the Ultrasonic Thickness Measurement Gauge. The Ultrasonic Thickness Measurement ... This investigation showed that the sand trap built in situ to sieve the sand and stones from the oil reservoir had failed. Keywords: erosion wear rate, metal losses, ...

  9. Technological parameters of welding of branch saddles to polyethylene pipes at low temperatures (United States)

    Starostin, N. P.; Vasilieva, M. A.


    The present paper outlines a procedure for determination of dynamics of the temperature field during the welding of the branch saddle to the polyethylene gas pipeline at ambient temperatures below the normative. The analysis is accomplished by the finite element method with the heat of the phase transition taken into account. Methods of the visualization of data sets reveal the possibility of controlling the thermal process by preheating and thermal insulation during welding of the branch saddle to the pipe at low temperatures and the possibility of obtaining the dynamics of the temperature field at which a high-quality welded joint is formed.

  10. Welding arc plasma physics (United States)

    Cain, Bruce L.


    The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

  11. Transient cavitation in pipelines

    NARCIS (Netherlands)

    Kranenburg, C.


    The aim of the present study is to set up a one-dimensional mathematical model, which describes the transient flow in pipelines, taking into account the influence of cavitation and free gas. The flow will be conceived of as a three-phase flow of the liquid, its vapour and non-condensible gas. The

  12. Welding skate with computerized controls (United States)

    Wall, W. A., Jr.


    New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.

  13. Computerized adaptive control weld skate with CCTV weld guidance project (United States)

    Wall, W. A.


    This report summarizes progress of the automatic computerized weld skate development portion of the Computerized Weld Skate with Closed Circuit Television (CCTV) Arc Guidance Project. The main goal of the project is to develop an automatic welding skate demonstration model equipped with CCTV weld guidance. The three main goals of the overall project are to: (1) develop a demonstration model computerized weld skate system, (2) develop a demonstration model automatic CCTV guidance system, and (3) integrate the two systems into a demonstration model of computerized weld skate with CCTV weld guidance for welding contoured parts.

  14. Modern Methods of Rail Welding (United States)

    Kozyrev, Nikolay A.; Kozyreva, Olga A.; Usoltsev, Aleksander A.; Kryukov, Roman E.; Shevchenko, Roman A.


    Existing methods of rail welding, which are enable to get continuous welded rail track, are observed in this article. Analysis of existing welding methods allows considering an issue of continuous rail track in detail. Metallurgical and welding technologies of rail welding and also process technologies reducing aftereffects of temperature exposure are important factors determining the quality and reliability of the continuous rail track. Analysis of the existing methods of rail welding enable to find the research line for solving this problem.

  15. Challenges to Resistance Welding

    DEFF Research Database (Denmark)

    Song, Quanfeng

    This report originates from the compulsory defense during my Ph.D. study at the Technical University of Denmark. Resistance welding is an old and well-proven technology. Yet the emergence of more and more new materials, new designs, invention off new joining techniques, and more stringent...... requirement in quality have imposed challenges to the resistance welding. More some research and development have to be done to adapt the old technology to the manufacturing industry of the 21st century. In the 1st part of the report, the challenging factors to the resistance welding are reviewed. Numerical...... simulation of resistance welding has been under development for many years. Yet it is no easy to make simulation results reliable and accurate because of the complexity of resistance welding process. In the 2nd part of the report numerical modeling of resistance welding is reviewed, some critical factors...

  16. Ultrasonic Stir Welding (United States)

    Nabors, Sammy


    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  17. Process stability during fiber laser-arc hybrid welding of thick steel plates (United States)

    Bunaziv, Ivan; Frostevarg, Jan; Akselsen, Odd M.; Kaplan, Alexander F. H.


    Thick steel plates are frequently used in shipbuilding, pipelines and other related heavy industries, and are usually joined by arc welding. Deep penetration laser-arc hybrid welding could increase productivity but has not been thoroughly investigated, and is therefore usually limited to applications with medium thickness (5-15 mm) sections. A major concern is process stability, especially when using modern welding consumables such as metal-cored wire and advanced welding equipment. High speed imaging allows direct observation of the process so that process behavior and phenomena can be studied. In this paper, 45 mm thick high strength steel was welded (butt joint double-sided) using the fiber laser-MAG hybrid process utilizing a metal-cored wire without pre-heating. Process stability was monitored under a wide range of welding parameters. It was found that the technique can be used successfully to weld thick sections with appropriate quality when the parameters are optimized. When comparing conventional pulsed and the more advanced cold metal transfer pulse (CMT+P) arc modes, it was found that both can provide high quality welds. CMT+P arc mode can provide more stable droplet transfer over a limited range of travel speeds. At higher travel speeds, an unstable metal transfer mechanism was observed. Comparing leading arc and trailing arc arrangements, the leading arc configuration can provide higher quality welds and more stable processing at longer inter-distances between the heat sources.

  18. Dual wire welding torch and method (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.


    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  19. Studies of welded joints

    Directory of Open Access Journals (Sweden)

    J. M. Krupa


    Full Text Available Studies of a welded joint were described. The joint was made as a result of the reconstruction of a truss and one of the possible means to make a repair. The studies were of a simulation character and were targeted at the detection of welding defects and imperfections thatshould be eliminated in a real structure. A model was designed and on this model the tests and examinations were carried out. The modelwas made under the same conditions as the conditions adopted for repair. It corresponded to the real object in shape and dimensions, and in the proposed technique of welding and welding parameters. The model was composed of five plates joined together with twelve beads.The destructive and non-destructive tests were carried out; the whole structure and the respective welds were also examined visually. Thedefects and imperfections in welds were detected by surface methods of inspection, penetration tests and magnetic particle flaw detection.The model of the welded joint was prepared by destructive methods, a technique that would never be permitted in the case of a realstructure. For the investigations it was necessary to cut out the specimens from the welded joint in direction transverse to the weld run. The specimens were subjected to metallographic examinations and hardness measurements. Additionally, the joint cross-section was examined by destructive testing methods to enable precise determination of the internal defects and imperfections. The surface methods were applied again, this time to determine the severity of welding defects. The analysis has proved that, fabricated under proper conditions and with parameters of the welding process duly observed, the welded joint has good properties and repairs of this type are possible in practice.

  20. 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)


    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)

  1. Robot welding process control (United States)

    Romine, Peter L.


    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  2. Stress analysis of vibrating pipelines (United States)

    Zachwieja, Janusz


    The pipelines are subject to various constraints variable in time. Those vibrations, if not monitored for amplitude and frequency, may result in both the fatigue damage in the pipeline profile at high stress concentration and the damage to the pipeline supports. If the constraint forces are known, the system response may be determined with high accuracy using analytical or numerical methods. In most cases, it may be difficult to determine the constraint parameters, since the industrial pipeline vibrations occur due to the dynamic effects of the medium in the pipeline. In that case, a vibration analysis is a suitable alternative method to determine the stress strain state in the pipeline profile. Monitoring the pipeline vibration levels involves a comparison between the measured vibration parameters and the permissible values as depicted in the graphs for a specific pipeline type. Unfortunately, in most cases, the studies relate to the petrochemical industry and thus large diameter, long and straight pipelines. For a pipeline section supported on both ends, the response in any profile at the entire section length can be determined by measuring the vibration parameters at two different profiles between the pipeline supports. For a straight pipeline section, the bending moments, variable in time, at the ends of the analysed section are a source of the pipe excitation. If a straight pipe section supported on both ends is excited by the bending moments in the support profile, the starting point for the stress analysis are the strains, determined from the Euler-Bernoulli equation. In practice, it is easier to determine the displacement using the experimental methods, since the factors causing vibrations are unknown. The industrial system pipelines, unlike the transfer pipelines, are straight sections at some points only, which makes it more difficult to formulate the equation of motion. In those cases, numerical methods can be used to determine stresses using the

  3. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines (United States)

    Moreira, EdsonVasques; Barbosa Rabello, JoséMaurício; Pereira, MarcelodosSantos; Lopes, RicardoTadeu; Zscherpel, Uwe


    Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array) is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

  4. Digital Radiography Using Digital Detector Arrays Fulfills Critical Applications for Offshore Pipelines

    Directory of Open Access Journals (Sweden)

    Lopes RicardoTadeu


    Full Text Available Digital radiography in the inspection of welded pipes to be installed under deep water offshore gas and oil pipelines, like a presalt in Brazil, in the paper has been investigated. The aim is to use digital radiography for nondestructive testing of welds as it is already in use in the medical, aerospace, security, automotive, and petrochemical sectors. Among the current options, the DDA (Digital Detector Array is considered as one of the best solutions to replace industrial films, as well as to increase the sensitivity to reduce the inspection cycle time. This paper shows the results of this new technique, comparing it to radiography with industrial films systems. In this paper, 20 test specimens of longitudinal welded pipe joints, specially prepared with artificial defects like cracks, lack of fusion, lack of penetration, and porosities and slag inclusions with varying dimensions and in 06 different base metal wall thicknesses, were tested and a comparison of the techniques was made. These experiments verified the purposed rules for parameter definitions and selections to control the required digital radiographic image quality as described in the draft international standard ISO/DIS 10893-7. This draft is first standard establishing the parameters for digital radiography on weld seam of welded steel pipes for pressure purposes to be used on gas and oil pipelines.

  5. Instrumented Pipeline Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Thomas Piro; Michael Ream


    This report summarizes technical progress achieved during the cooperative agreement between Concurrent Technologies Corporation (CTC) and U.S. Department of Energy to address the need for a for low-cost monitoring and inspection sensor system as identified in the Department of Energy (DOE) National Gas Infrastructure Research & Development (R&D) Delivery Reliability Program Roadmap.. The Instrumented Pipeline Initiative (IPI) achieved the objective by researching technologies for the monitoring of pipeline delivery integrity, through a ubiquitous network of sensors and controllers to detect and diagnose incipient defects, leaks, and failures. This report is organized by tasks as detailed in the Statement of Project Objectives (SOPO). The sections all state the objective and approach before detailing results of work.

  6. Pipeline corridors through wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, R.E.; Wilkey, P.L. [Argonne National Lab., IL (United States); Isaacson, H.R. [Gas Research Institute (United States)


    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  7. Pipeline corridors through wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, R.E.; Wilkey, P.L. (Argonne National Lab., IL (United States)); Isaacson, H.R. (Gas Research Institute (United States))


    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  8. Pipelined Asynchronous Cache Design


    Nyströem, Mika


    This thesis describes the development of pipelined asynchronous cache memories. The work is done in the context of the performance characteristics of memories and transistor logic of a late 1990's high-performance asynchronous microprocessor. We describe the general framework of asynchronous memory systems, caching, and those system characteristics that make caching of growing importance and keep it an interesting research topic. Finally, we present the main contribution of this work, whi...

  9. Introducing Library Pipeline

    Directory of Open Access Journals (Sweden)

    Brett Bonfield


    Full Text Available In Brief: We’re creating a nonprofit, Library Pipeline, that will operate independently from In the Library with the Lead Pipe, but will have similar and complementary aims: increasing and diversifying professional development; improving strategies and collaboration; fostering more innovation and start-ups, and encouraging LIS-related publishing and publications. In the Library with the Lead Pipe is […

  10. The Microstructure Evolution of Dual-Phase Pipeline Steel with Plastic Deformation at Different Strain Rates (United States)

    Ji, L. K.; Xu, T.; Zhang, J. M.; Wang, H. T.; Tong, M. X.; Zhu, R. H.; Zhou, G. S.


    Tensile properties of the high-deformability dual-phase ferrite-bainite X70 pipeline steel have been investigated at room temperature under the strain rates of 2.5 × 10-5, 1.25 × 10-4, 2.5 × 10-3, and 1.25 × 10-2 s-1. The microstructures at different amount of plastic deformation were examined by using scanning and transmission electron microscopy. Generally, the ductility of typical body-centered cubic steels is reduced when its stain rate increases. However, we observed a different ductility dependence on strain rates in the dual-phase X70 pipeline steel. The uniform elongation (UEL%) and elongation to fracture (EL%) at the strain rate of 2.5 × 10-3 s-1 increase about 54 and 74%, respectively, compared to those at 2.5 × 10-5 s-1. The UEL% and EL% reach to their maximum at the strain rate of 2.5 × 10-3 s-1. This phenomenon was explained by the observed grain structures and dislocation configurations. Whether or not the ductility can be enhanced with increasing strain rates depends on the competition between the homogenization of plastic deformation among the microconstituents (ultra-fine ferrite grains, relatively coarse ferrite grains as well as bainite) and the progress of cracks formed as a consequence of localized inconsistent plastic deformation.

  11. Measuring weld heat to evaluate weld integrity

    Energy Technology Data Exchange (ETDEWEB)

    Schauder, V., E-mail: [HKS-Prozesstechnik GmbH, Halle (Germany)


    Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

  12. Fine welding with lasers. (United States)

    MacLellan, D


    The need for micro joining metallic alloys for surgical instruments, implants and advanced medical devices is driving a rapid increase in the implementation of laser welding technology in research, development and volume production. This article discusses the advantages of this welding method and the types of lasers used in the process.

  13. Laser Welding in Space (United States)

    Workman, Gary L.; Kaukler, William F.


    Solidification type welding process experiments in conditions of microgravity were performed. The role of convection in such phenomena was examined and convective effects in the small volumes obtained in the laser weld zone were observed. Heat transfer within the weld was affected by acceleration level as indicated by the resulting microstructure changes in low gravity. All experiments were performed such that both high and low gravity welds occurred along the same weld beam, allowing the effects of gravity alone to be examined. Results indicate that laser welding in a space environment is feasible and can be safely performed IVA or EVA. Development of the hardware to perform the experiment in a Hitchhiker-g platform is recomended as the next step. This experiment provides NASA with a capable technology for welding needs in space. The resources required to perform this experiment aboard a Shuttle Hitchhiker-pallet are assessed. Over the four year period 1991 to 1994, it is recommended that the task will require 13.6 manyears and $914,900. In addition to demonstrating the technology and ferreting out the problems encountered, it is suggested that NASA will also have a useful laser materials processing facility for working with both the scientific and the engineering aspects of materials processing in space. Several concepts are also included for long-term optimization of available solar power through solar pumping solid state lasers directly for welding power.

  14. DC arc weld starter (United States)

    Campiotti, Richard H.; Hopwood, James E.


    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  15. Crack propagation and arrest of structural steels and pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Takehiro


    Crack arrest of fast running cracks is an important issue for the safety of steel structures. Crack arrest design can prevent fatal damage of large structures by restricting the influence of the incidents. Therefore crack arrest design is important especially for very large structure, where accidents may cause huge economical and social losses. Propagating shear fracture, long running ductile crack propagation in pipelines and brittle crack propagation in heavy thick shipbuilding steels have been investigated. For the propagating shear fracture issue, a new HLP simulation model, applicable to various backfill conditions, including underwater backfill, was developed. The proposed backfill model can be applied to the prediction of the crack arrest of propagating shear fracture under various backfill conditions. The new HLP simulation was successful in estimating full-scale burst tests with various backfill depths. The new HLP simulation for underwater pipelines indicated that propagating shear cracks are easily arrested in offshore pipelines compared to onshore pipeline. The toughness requirement of the line pipe for preventing propagating shear fracture can be significantly smaller in underwater pipelines compared to onshore pipelines. The margin of the underwater pipeline for propagating shear fracture was clarified by the new model developed in this thesis. For brittle crack arrest, an empirical approach for long crack propagation has been conducted. Several large-scale crack arrest tests were carried out in order to investigate the long crack arrestability of heavy-thick shipbuilding steel plates. All plates and their welded joints used in this study satisfied the Charpy toughness requirement for EH-grade shipbuilding steels and welded joints. A brittle crack ran along a welded joint and penetrated through the test plate under a stress exceeding 200MPa, despite the presence of longitudinal stiffeners across the test weld. A brittle crack in a base plate model

  16. Robotic system for orbital welding of pipes; Sistema robotizado para soldagem orbital de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Bracarense, Alexandre Queiroz; Lima II, Eduardo Jose; Torres, Guilherme Fortunato; Ramalho, Frederico [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Felizardo, Ivanilza; Zanon, Gislaine Pires [ROTECH Tecnologia Robotica Ltda., Belo Horizonte, MG (Brazil)


    This work presents the robotic system projected for orbital welding of pipelines of oil and gas. The system consists of a controller (microcomputer), that allows the execution of all the referring tasks to the welding in an autonomous way, and two manipulates, to what are coupled the welding torches that are connected to a welding power source with double wire feeders. With this system, GMA W process is used to execute the root pass, while FCA W process, besides the GMA W, is used for the filling and finishing passes. The system has four degrees of freedom, allowing the control of stick out, travel speed, torch angle and positioning. Besides these, the arc voltage and and welding current are also controlled during the process. Knowing that for each welding position (plane, vertical up and down and over head) a great group of parameters must be used, several tests were accomplished. With these values a controlled variation could be accomplished in an uninterrupted way when welding position changes, getting the increase of the productivity and also the quality of the weld performed by a robotic system. (author)

  17. Slurry pipeline technology: an overview

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Jay P. [Pipeline Systems Incorporated (PSI), Belo Horizonte, MG (Brazil); Lima, Rafael; Pinto, Daniel; Vidal, Alisson [Ausenco do Brasil Engenharia Ltda., Nova Lima, MG (Brazil). PSI Div.


    Slurry pipelines represent an economical and environmentally friendly transportation means for many solid materials. This paper provides an over-view of the technology, its evolution and current Brazilian activity. Mineral resources are increasingly moving farther away from ports, processing plants and end use points, and slurry pipelines are an important mode of solids transport. Application guidelines are discussed. State-of-the-Art technical solutions such as pipeline system simulation, pipe materials, pumps, valves, automation, telecommunications, and construction techniques that have made the technology successful are presented. A discussion of where long distant slurry pipelines fit in a picture that also includes thickened and paste materials pipe lining is included. (author)

  18. Welding method, and welding device for use therein, and method of analysis for evaluating welds

    NARCIS (Netherlands)

    Aendenroomer, A.J.; Den Ouden, G.; Xiao, Y.H.; Brabander, W.A.J.


    Described is a method of automatically welding pipes, comprising welding with a pulsation welding current and monitoring, by means of a sensor, the variations occurring in the arc voltage caused by weld pool oscillations. The occurrence of voltage variations with only frequency components below 100

  19. Thermoplastic welding apparatus and method (United States)

    Matsen, Marc R.; Negley, Mark A.; Geren, William Preston; Miller, Robert James


    A thermoplastic welding apparatus includes a thermoplastic welding tool, at least one tooling surface in the thermoplastic welding tool, a magnetic induction coil in the thermoplastic welding tool and generally encircling the at least one tooling surface and at least one smart susceptor in the thermoplastic welding tool at the at least one tooling surface. The magnetic induction coil is adapted to generate a magnetic flux field oriented generally parallel to a plane of the at least one smart susceptor.

  20. Laser forming and welding processes

    CERN Document Server

    Yilbas, Bekir Sami; Shuja, Shahzada Zaman


    This book introduces model studies and experimental results associated with laser forming and welding such as laser induced bending, welding of sheet metals, and related practical applications. The book provides insight into the physical processes involved with laser forming and welding. The analytical study covers the formulation of laser induced bending while the model study demonstrates the simulation of bending and welding processes using the finite element method. Analytical and numerical solutions for laser forming and welding problems are provided.

  1. Influence of Post-Weld Heat Treatment on the Microstructure, Microhardness, and Toughness of a Weld Metal for Hot Bend

    Directory of Open Access Journals (Sweden)

    Xiu-Lin Han


    Full Text Available In this work, a weld metal in K65 pipeline steel pipe has been processed through self-designed post-weld heat treatments including reheating and tempering associated with hot bending. The microstructures and the corresponding toughness and microhardness of the weld metal subjected to the post-weld heat treatments have been investigated. Results show that with the increase in reheating temperature, austenite grain size increases and the main microstructures transition from fine polygonal ferrite (PF to granular bainitic ferrite (GB. The density of the high angle boundary decreases at higher reheating temperature, leading to a loss of impact toughness. Lots of martensite/austenite (M/A constituents are observed after reheating, and to a large extent transform into cementite after further tempering. At high reheating temperatures, the increased hardenability promotes the formation of large quantities of M/A constituents. After tempering, the cementite particles become denser and coarser, which considerably deteriorates the impact toughness. Additionally, microhardness has a good linear relation with the mean equivalent diameter of ferrite grain with a low boundary tolerance angle (2°−8°, which shows that the hardness is controlled by low misorientation grain boundaries for the weld metal.

  2. Welding processes handbook

    CERN Document Server

    Weman, Klas


    Deals with the main commercially significant and commonly used welding processes. This title takes the student or novice welder through the individual steps involved in each process in an easily understood way. It covers many of the requirements referred to in European Standards including EN719, EN 729, EN 729 and EN 287.$bWelding processes handbook is a concise, explanatory guide to the main commercially significant and commonly-used welding processes. It takes the novice welder or student through the individual steps involved in each process in a clear and easily understood way. It is intended to provide an up-to-date reference to the major applications of welding as they are used in industry. The contents have been arranged so that it can be used as a textbook for European welding courses in accordance with guidelines from the European Welding Federation. Welding processes and equipment necessary for each process are described so that they can be applied to all instruction levels required by the EWF and th...

  3. Thermal stir welding process (United States)

    Ding, R. Jeffrey (Inventor)


    A welding method is provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  4. Thermal stir welding apparatus (United States)

    Ding, R. Jeffrey (Inventor)


    A welding method and apparatus are provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  5. Solar array welding developement (United States)

    Elms, R. V., Jr.


    The present work describes parallel gap welding as used for joining solar cells to the cell interconnect system. Sample preparation, weldable cell parameter evaluation, bond scheduling, bond strength evaluation, and bonding and thermal shock tests are described. A range of weld schedule parameters - voltage, time, and force - can be identified for various cell/interconnect designs that will provide adequate bond strengths and acceptably small electrical degradation. Automation of solar array welding operations to a significant degree has been achieved in Europe and will be receiving increased attention in the U.S. to reduce solar array fabrication costs.

  6. Review of Welding Terminology

    Directory of Open Access Journals (Sweden)

    Angelika Petrėtienė


    Full Text Available The paper discusses welding terms in accordance with the Lithuanian standard LST EN 1792 „Welding. The multilingual list of welding terms and similar processes”, „The Russian–Lithuanian dictionary of the terms of mechanical engineering technology and welding“ and the examples from postgraduates‘ final works. It analyses the infringement of lexical, word-building and morphological rules. First-year students should already be familiar with the standardized terms of their speciality. More active propagation of the terms should help to avoid terminology mistakes in various scientific spheres.

  7. Hydrodynamics of ocean pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihara, S.; Toyoda, S.; Venkataramana, K.; Aiko, Y. (Kagoshima University, Kagoshima (Japan). Faculty of Engineering)


    This paper describes the current forces acting on cylindrical models in a steady flow, corresponding to the cases of rigid and large diameter pipelines in real seas. The models were placed in a circulating water channel normal to the direction of flow. The strains in the models were recorded using strain gauges, from which fluid forces in the horizontal and vertical directions were obtained. The drag coefficient, lift coefficient, and Straul number were calculated, and were illustrated against the Reynolds number. Consequently, the drag force was found to increase with flow velocity. In addition, it was shown that the variation of lift force was more complex and was affected by the eddies and other forms of turbulence around the models. For the model which consists of two pipes held together, it was found that the fluid forces were greater on the upstream side. It was provided that the fluid forces were also affected by the orientation of the pipelines. Furthermore, it was clarified that the values of hydrodynamic coefficients and Straul number were similar to the results for vertical cylinders in uniform flows. 5 refs., 16 figs.

  8. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  9. Hydrogen Induced Damage in Pipeline Steels (United States)

    Angus, Garrett R.

    statistical accuracy of the evaluation method employed. The total, irreversibly trapped, and diffusible hydrogen amounts were measured or estimated for each condition using a LECO interstitial analyzer and the American Welding Society method for measuring diffusible hydrogen concentrations. The total amount of diffusible hydrogen was highest for the 100XFalloy and lowest for the X52 alloy. The amount of trapped hydrogen was similar for all the alloys, implying that the number of irreversible trap sites were comparable. However, the diffusible hydrogen content was greatest for the 100XF alloy and lowest for the X52 alloy, which is believed to be related to the relatively high amount of grain boundary area and high dislocation density of the 100XF alloy. A qualitative analysis on the effect of microstructure and nonmetallic inclusions on HIC was performed and produced results that confirmed findings from literature. Cracking was observed around nonmetallic inclusions such as sulfides and oxides in the metal matrix. For materials in which both inclusion types were present, X60 and X70, HIC originated and was observed most often around sulfide type inclusions.

  10. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  11. Friction stir welding tool (United States)

    Tolle,; Charles R. , Clark; Denis E. , Barnes; Timothy, A [Ammon, ID


    A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

  12. Concurrent ultrasonic weld evaluation system (United States)

    Hood, Donald W.; Johnson, John A.; Smartt, Herschel B.


    A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

  13. Shipping Information Pipeline

    DEFF Research Database (Denmark)

    Jensen, Thomas

    , while contemporary research proposes Information Infrastructures (II) as a new IT artifact to be researched. Correspondingly, this thesis applies the concept of and design theory for II to improve containerized shipping. Activity Theory has guided the analysis of containerized shipping, following......This thesis applies theoretical perspectives from the Information Systems (IS) research field to propose how Information Technology (IT) can improve containerized shipping. This question is addressed by developing a set of design principles for an information infrastructure for sharing shipping...... information named the Shipping Information Pipeline (SIP). Review of the literature revealed that IS research prescribed a set of meta-design principles, including digitalization and digital collaboration by implementation of Inter-Organizational Systems based on Electronic Data Interchange (EDI) messages...

  14. Finite element thermal analysis of the fusion welding of a P92 steel pipe

    Directory of Open Access Journals (Sweden)

    A. H. Yaghi


    Full Text Available Fusion welding is common in steel pipeline construction in fossil-fuel power generation plants. Steel pipes in service carry steam at high temperature and pressure, undergoing creep during years of service; their integrity is critical for the safe operation of a plant. The high-grade martensitic P92 steel is suitable for plant pipes for its enhanced creep strength. P92 steel pipes are usually joined together with a similar weld metal. Martensitic pipes are sometimes joined to austenitic steel pipes using nickel based weld consumables. Welding involves severe thermal cycles, inducing residual stresses in the welded structure, which, without post weld heat treatment (PWHT, can be detrimental to the integrity of the pipes. Welding residual stresses can be numerically simulated by applying the finite element (FE method in Abaqus. The simulation consists of a thermal analysis, determining the temperature history of the FE model, followed by a sequentially-coupled structural analysis, predicting residual stresses from the temperature history.

    In this paper, the FE thermal analysis of the arc welding of a typical P92 pipe is presented. The two parts of the P92 steel pipe are joined together using a dissimilar material, made of Inconel weld consumables, producing a multi-pass butt weld from 36 circumferential weld beads. Following the generation of the FE model, the FE mesh is controlled using Model Change in Abaqus to activate the weld elements for each bead at a time corresponding to weld deposition. The thermal analysis is simulated by applying a distributed heat flux to the model, the accuracy of which is judged by considering the fusion zones in both the parent pipe as well as the deposited weld metal. For realistic fusion zones, the heat flux must be prescribed in the deposited weld pass and also the adjacent pipe elements. The FE thermal results are validated by comparing experimental temperatures measured by five thermocouples on the

  15. Weld formation control at electron beam welding with beam oscillations


    Trushnikov, Dmitriy; Koleva, Elena; Mladenov, Georgy; A. Shcherbakov


    Electron beam welding is used extensively to produce essential machine parts. The control of the basic beam parameters beam power or beam current at constant accelerating voltage, welding speed, current of focusing lens and distance between electron gun and welded sample surface is not enough to obtain at most of the regimes sound welds. Control of the focus position using analysis of the high frequency component of the current, collected by plasma, at periodic interactions on the beam (the o...

  16. Mechanism of selective corrosion in electrical resistance seam welded carbon steel pipe

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Fajardo, Pedro; Godinez Salcedo, Jesus; Gonzalez Velasquez, Jorge L. [Instituto Politecnico Nacional, Mexico D.F., (Mexico). Escuela Superior de Ingenieria Quimica e Industrias Extractivas. Dept. de Ingenieria Metalurgica


    In this investigation the studies of the mechanism of selective corrosion in electrical resistance welded (ERW) carbon steel pipe was started. Metallographic characterizations and evaluations for inclusions were performed. The susceptibility of ERW pipe to selective corrosion in sea water (NACE 1D182, with O{sub 2} or CO{sub 2} + H{sub 2}S) was studied by the stepped potential Potentiostatic electrochemical test method in samples of 1 cm{sup 3} (ASTM G5) internal surface of the pipe (metal base-weld). The tests were looking for means for predicting the susceptibility of ERW pipe to selective corrosion, prior to placing the pipeline in service. Manganese sulfide inclusions are observed deformed by the welding process and they are close to the weld centerline. A slight decarburization at the weld line is observed, and a distinct out bent fiber pattern remains despite the post-weld seam annealing. The microstructure of the weld region consists of primarily polygonal ferrite grains mixed with small islands of pearlite. It is possible to observe the differences of sizes of grain of the present phases in the different zones. Finally, scanning electron microscopic observation revealed that the corrosion initiates with the dissolution of MnS inclusions and with small crack between the base metal and ZAC. (author)

  17. Alternate Welding Processes for In-Service Welding (United States)


    Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

  18. Certification of a weld produced by friction stir welding (United States)

    Obaditch, Chris; Grant, Glenn J


    Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

  19. Subsea pipeline operational risk management

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.L.; Lanan, G.A.


    Resources used for inspection, maintenance, and repair of a subsea pipeline must be allocated efficiently in order to operate it in the most cost effective manner. Operational risk management aids in resource allocation through the use of risk assessments and cost/benefit analyses. It identifies those areas where attention must be focused in order to reduce risk. When they are identified, a company`s resources (i.e., personnel, equipment, money, and time) can then be used for inspection, maintenance, and/or repair of the pipeline. The results are cost effective risk reduction and pipeline operation with minimum expenditure.

  20. Natural gas pipeline technology overview.

    Energy Technology Data Exchange (ETDEWEB)

    Folga, S. M.; Decision and Information Sciences


    The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

  1. Effort problem of chemical pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Okrajni, J.; Ciesla, M.; Mutwil, K. [Silesian Technical University, Katowice (Poland)


    The problem of the technical state assessment of the chemical pipelines working under mechanical and thermal loading has been shown in the paper. The pipelines effort after the long time operating period has been analysed. Material geometrical and loading conditions of the crack initiation and crack growth process in the chosen object has been discussed. Areas of the maximal effort have been determined. The material structure charges after the long time operating period have been described. Mechanisms of the crack initiation and crack growth in the pipeline elements have been analysed and mutual relations between the chemical and mechanical influences have been shown. (orig.) 16 refs.

  2. Welding defects at friction stir welding

    Directory of Open Access Journals (Sweden)

    P. Podržaj


    Full Text Available The paper presents an overview of different types of defects at friction stir welding. In order to explain the reasons for their occurrence a short theoretical background of the process is given first. The main emphasis is on the parameters that influence the process. An energy supply based division of defects into three disjoint groups was used. The occurring defects are demonstrated on various materials.

  3. Workmanship standards for fusion welding (United States)

    Phillips, M. D.


    Workmanship standards manual defines practices, that adhere to rigid codes and specifications, for fusion welding of component piping, assemblies, and systems. With written and pictorial presentations, it is part of the operating procedure for fusion welding.

  4. Welding and Brazing Silicon Carbide (United States)

    Moore, T. J.


    Hot isostatic pressing and conventional furnace brazing effective under right conditions. Study performed showed feasibility of welding SiC using several welding and brazing techniques. Use of SiC improves engine efficiency by allowing increase in operating temperature. SiC successfully hot-pressure-welded at 3,550 degrees F (1,950 degrees C) in argon. Refinements of solid-state welding and brazing procedures used sufficient for some specific industrial applications.

  5. Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications (United States)

    Bjorkman, Gerry; Cantrell, Mark; Carter, Robert


    Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading

  6. Pipeline integrity handbook risk management and evaluation

    CERN Document Server

    Singh, Ramesh


    Based on over 40 years of experience in the field, Ramesh Singh goes beyond corrosion control, providing techniques for addressing present and future integrity issues. Pipeline Integrity Handbook provides pipeline engineers with the tools to evaluate and inspect pipelines, safeguard the life cycle of their pipeline asset and ensure that they are optimizing delivery and capability. Presented in easy-to-use, step-by-step order, Pipeline Integrity Handbook is a quick reference for day-to-day use in identifying key pipeline degradation mechanisms and threats to pipeline integrity. The book begins

  7. Logistics aspects of petroleum pipeline operations

    Directory of Open Access Journals (Sweden)

    W. J. Pienaar


    Full Text Available The paper identifies, assesses and describes the logistics aspects of the commercial operation of petroleum pipelines. The nature of petroleum-product supply chains, in which pipelines play a role, is outlined and the types of petroleum pipeline systems are described. An outline is presented of the nature of the logistics activities of petroleum pipeline operations. The reasons for the cost efficiency of petroleum pipeline operations are given. The relative modal service effectiveness of petroleum pipeline transport, based on the most pertinent service performance measures, is offered. The segments in the petroleum-products supply chain where pipelines can play an efficient and effective role are identified.

  8. Welding. Performance Objectives. Basic Course. (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  9. Welding. Performance Objectives. Intermediate Course. (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…


    Energy Technology Data Exchange (ETDEWEB)

    Kelvin T. Erickson; Ann Miller; E. Keith Stanek; C.H. Wu; Shari Dunn-Norman


    This report presents the results of an investigation into two methods of using the natural gas pipeline as a communication medium. The work addressed the need to develop secure system monitoring and control techniques between the field and control centers and to robotic devices in the pipeline. In the first method, the pipeline was treated as a microwave waveguide. In the second method, the pipe was treated as a leaky feeder or a multi-ground neutral and the signal was directly injected onto the metal pipe. These methods were tested on existing pipeline loops at UMR and Batelle. The results reported in this report indicate the feasibility of both methods. In addition, a few suitable communication link protocols for this network were analyzed.

  11. Cold weld cracking susceptibility of high strength low alloyed (HSLA steel NIONIKRAL 70

    Directory of Open Access Journals (Sweden)

    A. S. Tawengi


    Full Text Available In view of the importance of high strength low alloy (HSLA steels, particularly for critical applications such as offshore plat forms, pipeline and pressure vessels, this paper reports on an investigation of how to weld this type of steel without cold cracking. Using manual metal arc welding process and Tekken test (Y - Grove test has been carried out both to observe the cold cracking phenome non, and to investigate the influencing factors, such as preheating temperature and energy input, as well as electrode strength and diameter. How ever the results of the experiments show that there is a risk of cold cracking.

  12. Friction stir welding tool and process for welding dissimilar materials (United States)

    Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F


    A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

  13. Ultrasonic Evaluation of Weld Strength for Aluminum Ultrasonic Spot Welds (United States)

    Ghaffari, Bita; Hetrick, Elizabeth T.; Mozurkewich, George; Reatherford, Larry V.


    The goal of this work is to determine the feasibility of using an ultrasonic, non-destructive technique for post-process evaluation of aluminum ultrasonic spot welds. A focused immersion transducer was utilized to obtain a C-scan of the weld interface, from which a weighted ultrasonic contact area was estimated. Weldments were subsequently tested destructively to determine the weld strength. The square root of the weld contact area displayed a relatively good correlation with weld strength, r2=0.85.

  14. Pipeline for Contraceptive Development (United States)

    Blithe, Diana L.


    The high rates of unplanned pregnancy reflect unmet need for effective contraceptive methods for women, especially for individuals with health risks such as obesity, diabetes, hypertension, and other conditions that may contraindicate use of an estrogen-containing product. Improvements in safety, user convenience, acceptability and availability of products remain important goals of the contraceptive development program. Another important goal is to minimize the impact of the products on the environment. Development of new methods for male contraception has the potential to address many of these issues with regard to safety for women who have contraindications to effective contraceptive methods but want to protect against pregnancy. It also will address a huge unmet need for men who want to control their fertility. Products under development for men would not introduce eco-toxic hormones in the waste water. Investment in contraceptive research to identify new products for women has been limited in the pharmaceutical industry relative to investment in drug development for other indications. Pharmaceutical R&D for male contraception was active in the 1990’s but was abandoned over a decade ago. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) has supported a contraceptive development program since 1969. Through a variety of programs including research grants and contracts, NICHD has developed a pipeline of new targets/products for male and female contraception. A number of lead candidates are under evaluation in the NICHD Contraceptive Clinical Trials Network (CCTN) (1–3). PMID:27523300

  15. Weld bead profile of laser welding dissimilar joints stainless steel (United States)

    Mohammed, Ghusoon R.; Ishak, M.; Aqida, S. N.; Abdulhadi, Hassan A.


    During the process of laser welding, the material consecutively melts and solidifies by a laser beam with a peak high power. Several parameters such as the laser energy, pulse frequency, pulse duration, welding power and welding speed govern the mode of the welding process. The aim of this paper is to investigate the effect of peak power, incident angle, and welding speed on the weld bead geometry. The first investigation in this context was conducted using 2205-316L stainless steel plates through the varying of the welding speed from 1.3 mm/s to 2.1 mm/s. The second investigation was conducted by varying the peak power from 1100 W to 1500 W. From the results of the experiments, the welding speed and laser power had a significant effect on the geometry of the weld bead, and the variation in the diameter of the bead pulse-size. Due to the decrease in the heat input, welding speed affected penetration depth more than bead width, and a narrow width of heat affected zone was achieved ranging from 0.2 to 0.5 mm. Conclusively, weld bead geometry dimensions increase as a function of peak power; at over 1350 W peak power, the dimensions lie within 30 μm.

  16. Environmental management systems methodology for pipeline systems implementation; Metodologia para implantacao de sistemas de gestao ambiental na implementacao de empreendimentos dutoviarios

    Energy Technology Data Exchange (ETDEWEB)

    Paz, Claudio Marques [JPTE Engenharia Ltda., Barueri, SP (Brazil); Pinaud, Rodrigo Zambrotti [AJR Engenharia - Seguranca, Meio Ambiente e Saude Ltda. (Brazil)


    The implementation of oil and gas pipeline systems are commonly made in a own or shared with power transmission, rail and crossroads right-of-way. Pipelines are a 'linear' structure, such as power transmission lines, which are established on landscapes with several conformations (accent slopes, swamp and rocky soils), including sites with high environmental sensibility. The services involved on pipeline implementation are very dynamic, involving several number of employees, vehicles, heavy equipment of excavation and welding that results in a high potential to cause environmental and social impacts. This article, based on the Brazilian and foreign experience on pipeline construction, proposes a methodology to prevent and minimize social and environmental impacts during the construction stage of a pipeline system. (author)

  17. Weld Nugget Temperature Control in Thermal Stir Welding (United States)

    Ding, R. Jeffrey (Inventor)


    A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

  18. Numerical simulation of welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær; Thorborg, Jesper

    Aim of project:To analyse and model the transient thermal field from arc welding (SMAW, V-shaped buttweld in 15mm plate) and to some extend the mechanical response due to the thermal field. - To implement this model in a general purpose finite element program such as ABAQUS.The simulation...... stress is also taken into account.Work carried out:With few means it is possible to define a thermal model which describes the thermal field from the welding process in reasonable agreement with reality. Identical results are found with ABAQUS and Rosenthal’s analytical solution of the governing heat...... transfer equation under same conditions. It is relative easy tointroduce boundary conditions such as convection and radiation where not surprisingly the radiation has the greatest influence especially from the high temperature regions in the weld pool and the heat affected zone.Due to the large temperature...

  19. Extravehicular activity welding experiment (United States)

    Watson, J. Kevin


    The In-Space Technology Experiments Program (INSTEP) provides an opportunity to explore the many critical questions which can only be answered by experimentation in space. The objective of the Extravehicular Activity Welding Experiment definition project was to define the requirements for a spaceflight experiment to evaluate the feasibility of performing manual welding tasks during EVA. Consideration was given to experiment design, work station design, welding hardware design, payload integration requirements, and human factors (including safety). The results of this effort are presented. Included are the specific objectives of the flight test, details of the tasks which will generate the required data, and a description of the equipment which will be needed to support the tasks. Work station requirements are addressed as are human factors, STS integration procedures and, most importantly, safety considerations. A preliminary estimate of the cost and the schedule for completion of the experiment through flight and postflight analysis are given.

  20. Pulsed welding plasma source (United States)

    Knyaz'kov, A.; Pustovykh, O.; Verevkin, A.; Terekhin, V.; Shachek, A.; Tyasto, A.


    It is shown that in order to form the current pulse of a near rectangular shape, which provides conversion of the welding arc into a dynamic mode, it is rational to connect a forming element made on the basis of an artificial forming line in series to the welding DC circuit. The paper presents a diagram of a pulsed device for welding with a non-consumable electrode in argon which was developed using the forming element. The conversion of the arc into the dynamic mode is illustrated by the current and voltage oscillograms of the arc gap and the dynamic characteristic of the arc within the interval of one pulse generation time in the arc gap. The background current travels in the interpulse interval.

  1. Ternary gas plasma welding torch (United States)

    Rybicki, Daniel J. (Inventor); Mcgee, William F. (Inventor); Waldron, Douglas J. (Inventor)


    A plasma arc welding torch is discussed. A first plasma gas is directed through the body of the welding torch and out of the body across the tip of a welding electrode disposed at the forward end of the body. A second plasma gas is disposed for flow through a longitudinal bore in the electrode. The second plasma gas enters one end of the electrode and exits the electrode at the tip thereof for co-acting with the electric welding arc to produce the desired weld. A shield gas is directed through the torch body and circulates around the head of the torch adjacent to the electrode tip.

  2. Effect of Hot-Bending Process on Microstructure and Mechanical Property of K65 Submerged ARC Welded Pipe (United States)

    Dong, Liming; Zhang, Yu; Pan, Xin; Wang, Yinbai

    Hot-bended pipes are essential parts in the construction of long distance pipeline. They are usually made from longitudinally submerged arc welding (LSAW) pipes subjected to hot bending process including quenching and tempering process, which often deteriorates the impact property of the welded pipe. A hot-bended LSAW pipe with a wall thickness of 30.8 mm was fabricated by double-sided four wires submerged arc welding with solid wire and fused flux. Microstructural and property of both as-weld and as-bended pipe were examined. The pipes in two states show a similar tensile strength of 665-670 MPa, and fail in the heat affected zone during the tensile test. The weld metal of as-welded pipe consists of acicular ferrite and small fraction bainite and M-A constituents, while mixture of polygonal ferrite, degenerate perlite and precipitated carbides of metal elements was found in the weld metal of the as-bended pipe. The hot bending process decreases the fraction of acicular ferrite from 66.4 to 47.5%, and the fraction of high angle grain boundary from 76.8 to 67.1%. Therefore, both the type of microstructure and the fraction of ductile microstructures were the influencing factors of weld metal impact toughness, which lead to a reduction from 162 J to 84 J at -40°C.

  3. Integrated sensors for robotic laser welding

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Beyer, E.; Dausinger, F; Ostendorf, A; Otto, A.


    A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as

  4. Sensor integration for robotic laser welding processes

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Ostendorf, A; Hoult, A.; Lu, Y.


    The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process,

  5. Acoustic-Emission Weld-Penetration Monitor (United States)

    Maram, J.; Collins, J.


    Weld penetration monitored by detection of high-frequency acoustic emissions produced by advancing weld pool as it melts and solidifies in workpiece. Acoustic emission from TIG butt weld measured with 300-kHz resonant transducer. Rise in emission level coincides with cessation of weld penetration due to sudden reduction in welding current. Such monitoring applied to control of automated and robotic welders.

  6. Weld procedure development with OSLW - optimization software for laser welding

    Energy Technology Data Exchange (ETDEWEB)

    Fuerschbach, P.W.; Eisler, G.R. [Sandia National Labs., Albuquerque, NM (United States); Steele, R.J. [Naval Air Warfare Center, China Lake, CA (United States)


    Weld procedure development can require extensive experimentation, in-depth process knowledge, and is further complicated by the fact that there are often multiple sets of parameters that will meet the weld requirements. Choosing among these multiple weld procedures can be hastened with computer models that find parameters to meet selected weld dimensional requirements while simultaneously optimizing important figures of merit. Software is described that performs this task for CO{sub 2} laser beam welding. The models are based on dimensionless parameter correlations that are derived from solutions to the moving heat source equations. The use of both handbook and empirically verified thermophysical property values allows OSLW to be extended to many different materials. Graphics displays show the resulting solution on contour plots that can be used to further probe the model. The important figures of merit for laser beam welding are energy transfer efficiency and melting efficiency. The application enables the user to input desired weld shape dimensions, select the material to be welded, and to constrain the search problem to meet the application requirements. Successful testing of the software at a laser welding fabricator has validated this tool for weld procedure development.

  7. Welding. Student Learning Guide. (United States)

    Palm Beach County Board of Public Instruction, West Palm Beach, FL.

    This student learning guide contains 30 modules for completing a course in welding. It is designed especially for use in secondary schools in Palm Beach County, Florida. Each module covers one task, and consists of a purpose, performance objective, enabling objectives, learning activities keyed to resources, information sheets, student self-check…

  8. Thermal Stresses in Welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær


    Studies of the transient temperature fields and the hereby induced deformations and stressses in a butt-welded mild steel plate modelledrespectively in 2D plane stress state (as well as plane strain state) and in full 3D have been done. The model has been implemented in the generalpurpose FE...

  9. Elementary TIG Welding Skills. (United States)

    Pierson, John E., III

    The text was prepared to help deaf students develop the skills needed by an employed welder. It uses simplified language and illustrations to present concepts which should be reinforced by practical experience with welding skills. Each of the 12 lessons contains: (1) an information section with many illustrations which presents a concept or…

  10. effect of post-weld heat treatment on the microstructure

    African Journals Online (AJOL)


    among others are shielded metal arc welding, submerge arc welding, gas metal arc welding, plasma arc welding, gas ... welding (SMAW) technique is preferable to the other techniques ..... studies''International Journal of Innovative Research.

  11. SHADOW: a new welding technique (United States)

    Kramer, Thorsten; Olowinsky, Alexander M.; Durand, Friedrich


    The new welding technique 'SHADOW ' is introduced. SHADOW means the use of a single pulse to generate a quasi continuous weld of several millimeters in length. HET processing time is defined by the pulse duration of the pulsed laser. At present, a state-of-the-art laser is capable of a maximum pulse duration of 20 ms. The variation of the laser power depend on time is a vital capability of the pulsed laser to adapt the energy deposition into the workpiece. Laser beam welds of several watch components were successfully performed. Similar metals like crowns and axes made out of stainless steel have been welded using pulsed laser radiation. Applying a series of about 130 single pulses for the crown-axis combination the total energy accumulates to 19.5 J. The use of the SHADOW welding technique reduces the energy to 2.5 J. While welding dissimilar metals like stainless steel and bras, the SHADOW welding reduces drastically the contamination as well as the distortion. Laser beam welding of copper has a low process reliability due to the high reflection and the high thermal conductivity. SHADOW welds of 3.6 mm length were performed on 250 micrometers thick copper plates with very high reproducibility. As a result, a pilot plant for laser beam welding of copper plates has been set up. The work to be presented has partly been funded by the European Commission in a project under the contract BRPR-CT-0634.

  12. Avaliação da Influência de Tratamentos Térmicos Pós-Soldagem Sobre a Microestrutura e Propriedades Mecânicas de Juntas de um Aço API 5L X70Q

    Directory of Open Access Journals (Sweden)

    Lívia Carla Silva de Araújo


    Full Text Available ResumoAços que atendem à norma API 5L são aplicados na construção de dutos e há grande interesse naqueles de maior resistência, como o grau API 5L X70Q. Ainda são escassos os estudos relacionados a tubos sem costura. Durante a montagem, os tubos podem ser soldados por eletrodos revestidos (SMAW e eventualmente sofrer aquecimento indutivo para adequação à topografia do terreno, processos que podem alterar a microestrutura das juntas. Neste trabalho foram obtidas juntas soldadas pelo processo SMAW, a partir de tubo sem costura grau API 5L X70Q. As juntas foram submetidas a tratamentos térmicos pós-soldagem nas temperaturas 920 °C e 600 °C. Foram realizados ensaios de tração, impacto Charpy e microdureza, além de caracterização metalográfica nas amostras de metal base e nas juntas como soldadas e após os tratamentos térmicos. O tratamento térmico a 920 °C promoveu a formação de estrutura ferrita/perlita, com consequente redução na resistência mecânica das juntas a valores inferiores aos especificados para o grau X70Q. Porém, o tratamento térmico a 600 °C mostrou-se benéfico devido à redução da fração volumétrica dos constituintes martensita/austenita e martensita-austenita-bainita, sem reduzir de forma significativa a resistência mecânica e com relativo ganho na tenacidade ao impacto na ZTA e na ZF.

  13. Energía calorífica necesaria, durante la soldadura en servicio de tuberías para el transporte de petróleo Necessary calorific energy, during the in-service welding of pipelines for petroleum transport

    Directory of Open Access Journals (Sweden)

    Félix Ramos Morales


    Full Text Available En el presente artículo, empleando el análisis por elementos finitos, se estudió el comportamiento térmico durante la soldadura de reparación, en condiciones de servicio, de un tubo que transporta petróleo. Se obtuvieron ecuaciones de regresión que relacionan a la temperatura máxima en la superficie interna del tubo y al tiempo de enfriamiento desde 800 ºC hasta 500 ºC de un punto situado en la zona afectada por el calor (ZAC, parámetros que gobiernan la ocurrencia de perforaciones en la pared del tubo y agrietamiento en frío respectivamente, con el calor de entrada de la soldadura, la temperatura de precalentamiento y el coeficiente de transferencia de calor por convección, variables que definen el comportamiento térmico durante la ejecución del proceso de soldadura. Se probó la existencia de una zona en que se satisfacen simultáneamente las ecuaciones obtenidas, para diferentes combinaciones de las variables relacionadas. Se presentaron nomogramas con un importante valor práctico, desarrollados a partir de la solución de las ecuaciones obtenidas.The thermal behavior during in service repair welding of oil transportation pipes was studied by finite element analysis in the present paper. Regression equations that relate peak temperature at the inner surface of the pipe and cooling time between 800 and 500ºC in the heat affected zone to the welding heat input, preheat temperature, and convection heat transfer coefficient were obtained. The former parameters govern, respectively, the possibility of burn through and cold cracking, and the latter parameters define the thermal behavior during welding. The existence of conditions that simultaneously satisfy the obtained equations, for different combinations of related variables, was proved. Graphical representations of relevant practical importance that were developed from the solution of obtained equations are presented.

  14. Welded repair joints of boiler steels following operation in creep conditions exceeding the design time of operation

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, J.; Paszkowska, H.; Zielinski, A. [Institute for Ferrous Metallurgy, Gliwice (Poland)


    The assessment of suitability for further operation for materials and welded repair joints of thick-walled main steam pipeline components, made of steel 14MoV63, as well as steam superheater outlet headers made of steel X20CrMoV121 following operation in creep conditions in time periods considerably longer than the specified calculated time of operation. Strength properties, impact strength and transition temperature into brittle condition, as well as structure condition have been evaluated. On the basis of shortened creep tests, the residual life and disposable residual life of materials and welded joints have been determined. Material properties following operation and those of fabricated circumferential welded repair joints have been compared. The condition of examined components and suitability of the fabricated welded repair joints for further operation have been assessed. (orig.)

  15. Welding residual stress distributions for dissimilar metal nozzle butt welds in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Soo; Kim, Ju Hee; Bae, Hong Yeol; OH, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyungsoo [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Song, Tae Kwang [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)


    In pressurized water nuclear reactors, dissimilar metal welds are susceptible to primary water stress corrosion cracking. To access this problem, accurate estimation of welding residual stresses is important. This paper provides general welding residual stress profiles in dissimilar metal nozzle butt welds using finite element analysis. By introducing a simplified shape for dissimilar metal nozzle butt welds, changes in the welding residual stress distribution can be seen using a geometry variable. Based on the results, a welding residual stress profile for dissimilar metal nozzle butt welds is proposed that modifies the existing welding residual stress profile for austenitic pipe butt welds.

  16. In-field Welding and Coating Protocols (United States)


    Gas Technology Institute (GTI) and Edison Welding Institute (EWI) created both laboratory and infield girth weld samples to evaluate the effects of weld geometry and hydrogen off-gassing on the performance of protective coatings. Laboratory made plat...

  17. Closed circuit TV system monitors welding operations (United States)

    Gilman, M.


    TV camera system that has a special vidicon tube with a gradient density filter is used in remote monitoring of TIG welding of stainless steel. The welding operations involve complex assembly welding tools and skates in areas of limited accessibility.

  18. Factors affecting weld root morphology in laser keyhole welding (United States)

    Frostevarg, Jan


    Welding production efficiency is usually optimised if full penetration can be achieved in a single pass. Techniques such as electron and laser beam welding offer deep high speed keyhole welding, especially since multi-kilowatt lasers became available. However, there are limitations for these techniques when considering weld imperfections such as weld cap undercuts, interior porosity or humps at the root. The thickness of sheets during full penetration welding is practically limited by these root humps. The mechanisms behind root morphology formation are not yet satisfactory understood. In this paper root humping is studied by reviewing previous studies and findings and also by sample examination and process observation by high speed imaging. Different process regimes governing root quality are presented, categorized and explained. Even though this study mainly covers laser beam and laser arc hybrid welding, the presented findings can generally be applied full penetration welding in medium to thick sheets, especially the discussion of surface tension effects. As a final result of this analysis, a map of methods to optimise weld root topology is presented.

  19. Dynamics of space welding impact and corresponding safety welding study. (United States)

    Fragomeni, James M; Nunes, Arthur C


    This study was undertaken in order to be sure that no hazard would exist from impingement of hot molten metal particle detachments upon an astronauts space suit during any future electron beam welding exercises or experiments. The conditions under which molten metal detachments might occur in a space welding environment were analyzed. The safety issue is important during welding with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at low earth orbit. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were determined for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. A weld pool detachment parameter for specifying the conditions for metal weld pool detachment by impact was derived and correlated to the experimental results. The experimental results were for the most part consistent with the theoretical analysis and predictions. c2003 Elsevier Ltd. All rights reserved.

  20. Dynamics of space welding impact and corresponding safety welding study (United States)

    Fragomeni, James M.; Nunes, Arthur C.


    This study was undertaken in order to be sure that no hazard would exist from impingement of hot molten metal particle detachments upon an astronauts space suit during any future electron beam welding exercises or experiments. The conditions under which molten metal detachments might occur in a space welding environment were analyzed. The safety issue is important during welding with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at low earth orbit. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were determined for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. A weld pool detachment parameter for specifying the conditions for metal weld pool detachment by impact was derived and correlated to the experimental results. The experimental results were for the most part consistent with the theoretical analysis and predictions.

  1. 77 FR 19799 - Pipeline Safety: Pipeline Damage Prevention Programs (United States)


    ... included excavation damage prevention. The Integrity Management for Gas Distribution, Report of Phase I...) The American Gas Association (AGA) The American Petroleum Institute (API) The American Public Gas... Locating Services, API, AOPL, INGAA, and several pipeline operators commented that PHMSA should develop the...

  2. Fundamental Laser Welding Process Investigations

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove


    In a number of systematic laboratory investigations the fundamental behavior of the laser welding process was analyzed by the use of normal video (30 Hz), high speed video (100 and 400 Hz) and photo diodes. Sensors were positioned to monitor the welding process from both the top side and the rear...... side of the specimen.Special attention has been given to the dynamic nature of the laser welding process, especially during unstable welding conditions. In one series of experiments, the stability of the process has been varied by changing the gap distance in lap welding. In another series...... video pictures (400 Hz), a clear impact on the seam characteristics has been identified when a hump occurs.Finally, a clear correlation between the position of the focus point, the resultant process type and the corresponding signal intensity and signal variation has been found for sheets welded...

  3. Thermal calculations of underground oil pipelines

    Directory of Open Access Journals (Sweden)

    Moiseev Boris


    Full Text Available Operation of oil pipelines in the frozen soil causes heat exchange between the pipeline and the soil and formation of a melt zone which leads to deformation of pipelines. Terms of construction and operation of oil pipelines are greatly related to their temperature conditions. In this regard it is necessary to know the laws of formation of thawing halos around oil pipelines. Thus, elucidation of laws of formation of thawing halos around oil pipelines and determination of optimal conditions for their installation during construction in areas of permafrost in the north of Tyumen region is a very urgent task. The authors developed an algorithm and a computer program for construction of the temperature field of the frozen soil. Some problems have been solved basing on the obtained dependences and graphs of the dependence were constructed. Research and calculations made on the underground oil pipeline construction allowed the authors to give recommendations aimed at increasing the reliability of oil pipelines.

  4. Method and system for pipeline communication (United States)

    Richardson,; John, G [Idaho Falls, ID


    A pipeline communication system and method includes a pipeline having a surface extending along at least a portion of the length of the pipeline. A conductive bus is formed to and extends along a portion of the surface of the pipeline. The conductive bus includes a first conductive trace and a second conductive trace with the first and second conductive traces being adapted to conformally couple with a pipeline at the surface extending along at least a portion of the length of the pipeline. A transmitter for sending information along the conductive bus on the pipeline is coupled thereto and a receiver for receiving the information from the conductive bus on the pipeline is also couple to the conductive bus.

  5. The Measurement of Hardness and Elastic Modulus of non-Metallic Inclusions in Steely Welding Joints

    Directory of Open Access Journals (Sweden)

    Ignatova Anna


    Full Text Available Trunk pipelines work under a cyclic dynamical mechanical load because when oil or gas is pumped, the pressure constantly changes - pulsates. Therefore, the fatigue phenomenon is a common reason of accidents. The fatigue phenomenon more often happens in the zone of non-metallic inclusions concentration. To know how the characteristics of nonmetallic inclusions influence the probability of an accident the most modern research methods should be used. It is determined with the help of the modern research methods that the accident rate of welded joints of pipelines is mostly influenced by their morphological type, composition and size of nonmetallic inclusions, this effect is more important than the common level of pollution by non-metallic inclusions. The article presents the results of the investigations of welded joints, obtained after the use of different common welding materials. We used the methods, described in the state standards: scanning electronic microscopy, spectral microprobe analysis and nano-indentation. We found out that non-metallic inclusions act like stress concentrators because they shrink, forming a blank space between metal and nonmetallic inclusions; it strengthens the differential properties on this boundary. Nonmetallic inclusion is not fixed, it can move. The data that we have received mean that during welded joints’ contamination (with non-metallic inclusions monitoring process, more attention should be paid to the content of definite inclusions, but not to total contamination.

  6. Pulsed ultrasonic stir welding system (United States)

    Ding, R. Jeffrey (Inventor)


    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  7. California Natural Gas Pipelines: A Brief Guide

    Energy Technology Data Exchange (ETDEWEB)

    Neuscamman, Stephanie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Price, Don [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pezzola, Genny [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glascoe, Lee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)


    The purpose of this document is to familiarize the reader with the general configuration and operation of the natural gas pipelines in California and to discuss potential LLNL contributions that would support the Partnership for the 21st Century collaboration. First, pipeline infrastructure will be reviewed. Then, recent pipeline events will be examined. Selected current pipeline industry research will be summarized. Finally, industry acronyms are listed for reference.

  8. Risks associated with South African energy pipelines



    M.Comm. The demand for products which are distributed through pipelines has increased worldwide over the last decade. These increases in demand have irrevocably impacted upon top management’s perceptions of risks associated with energy pipeline supply chains. Even in South Africa, the increase in demand for products such as diesel, jet fuel and petrol, which are supplied through the energy pipeline supply chains have increased the risks associated with energy pipeline supply chains. This s...

  9. Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen


    In the offshore industry, welding-induced distortion and tensile residual stresses have become a major concern in relation to the structural integrity of a welded structure. Particularly, the continuous increase in size of welded plates and joints needs special attention concerning welding induced...... residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature failure in the weld components. This paper deals with the influence and impact of welding method on the welding...... induced residual stresses. It is also investigated whether the assumption of residual stresses up to yield strength magnitude are present in welded structures as stated in the design guidelines. The fatigue strength for welded joints is based on this assumption. The two welding methods investigated...

  10. The effect of post-welding conditions in friction stir welds: From weld simulation to Ductile Failure

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Nielsen, Kim Lau; Tutum, Cem Celal


    effect of the post-welding conditions when subjecting a friction stir weld to loading transverse to the weld line. The numerical model of the friction stir welded joint, employs a step-wise modeling approach to combine an in-situ weld simulation with a post-welding failure analysis. Using the commercial......The post-welding stress state, strain history and material conditions of friction stir welded joints are often strongly idealized when used in subsequent modeling analyses, typically by neglecting one or more of the features above. But, it is obvious that the conditions after welding do influence...... the weld performance. The objective of this paper is to discuss some of the main conflicts that arise when taking both the post-welding material conditions and stressestrain state into account in a subsequent structural analysis. The discussion is here based on a preliminary numerical study of the possible...

  11. Geotechnical characterization and finite element pipe/soil interaction modeling of a pipeline installed in an actively moving, permafrost slope

    Energy Technology Data Exchange (ETDEWEB)

    Bidwell, A. [AMEC Earth and Environmental, Calgary, AB (Canada); Sen, M.; Pederson, I. [Enbridge Pipelines Inc., Edmonton, AB (Canada); Yoosef-Ghodsi, N. [C-FER Technologies, Edmonton, AB (Canada)


    This paper discussed a pipeline integrity analysis for a buried crude-oil pipeline at a site characterized by unstable permafrost slopes. Data collected from piezometers, inclinometers, and thermistor cables installed as part of a comprehensive geotechnical monitoring program were used to determine the geotechnical character of the site and model pipe/soil interactions. A finite element pipe/soil interaction model was developed to estimate the potential strain to the pipeline capacity in a worst-case scenario involving mass soil movement. The purpose was to determine the necessity of costly mitigation measures. The model showed that the pipeline strain capacity is unlikely to be exceeded in the event of a sudden ground movement at the slope. The soil, permafrost, and slope movement conditions at the site were described along with the methodology and results of the pipe/soil interaction model. The model, in which the pipeline is considered as a continuous structural beam, was used to analyze both the estimated current slope movement and the worst case large magnitude slope movement. To assess the pipeline integrity in the event of mass slope movement, the expected strain demand was compared to the strain capacity, taking into account whether the pipe is heavy wall, line pipe, or containing girth welds. The analysis indicated that the risk of pipeline failure is low in the event of a large magnitude slope movement. The pipe strain measurements were found to be within the design limits for the pipeline. The analysis is relevant to other northern pipeline and linear infrastructure developments. 8 refs., 6 figs.

  12. Overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adarlan M.; Passos, Aline C.; Santos, Daniel; Orban, Eduardo M.; Lisboa, Helder D.; Goncalves, Nilton; Guimaraes, Robson C. [Anglo Ferrous Brazil, Rio de Janeiro, RJ (Brazil)


    The objective of this paper is to present an overview of the long distance iron ore slurry pipeline from Anglo Ferrous Brazil. Anglo Ferrous Brazil is a company of Anglo American plc that is one of the world's largest mining and natural resource company. Minas-Rio is a world class iron ore project which has been developed in Brazil aiming to produce 26.6 million tons per year of concentrate. The mine, concentrator and pump station 1 will be located in Conceicao do Mato Dentro, Minas Gerais state, and the terminal station will be located at Acu Port in Sao Joao da Barra, Rio de Janeiro state. The long distance iron ore slurry pipeline will be one of major differentials of Minas-Rio Project and its useful life was initially estimated in 20 years. The slurry pipeline has a total length of 525 kilometers and will be constructed from predominately 26 inches external diameter API 5L X70 pipes. From kilometer 314 to kilometer 480, 24 inches pipe will be installed to prevent slack flow downstream pump station 2. The pump station 1 is designed to provide the hydraulic head necessary to transport the concentrate iron ore slurry with 8 positive displacement pumps to pump station 2. The pump station 2, located 240 kilometers downstream pump station 1, is designed to operate with 10 positive displacement pumps. The valve station will be located at kilometer 347 and will be used to break the static head between pump station 2 and the terminal station during a slurry pipeline shutdown. (author)

  13. Pulsed ultrasonic stir welding method (United States)

    Ding, R. Jeffrey (Inventor)


    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  14. Reconditioning medical prostheses by welding (United States)

    Rontescu, C.; Cicic, D. T.; Vasile, I. M.; Bogatu, A. M.; Amza, C. G.


    After the technological process of making, some of the medical prostheses may contain imperfections, which can lead to framing the product in the spoilage category. This paper treats the possibility of reconditioning by welding of the prosthesis made of titanium alloys. The paper presents the obtained results after the reconditioning by welding, using the GTAW process, of a intramedullary rod type prosthesis in which was found a crack after the non-destructive examination. The obtained result analysis, after the micrographic examination of the welded joint areas, highlighted that the process of reconditioning by welding can be applied successfully in such situations.

  15. Portable electron beam weld chamber (United States)

    Lewis, J. R.; Dimino, J. M.


    Development and characteristics of portable vacuum chamber for skate type electron beam welding are discussed. Construction and operational details of equipment are presented. Illustrations of equipment are provided.

  16. Pipelines cathodic protection design methodologies for impressed ...

    African Journals Online (AJOL)

    ... X42 pipeline with total external surface area of 226224m2. The computation further showed the current requirement was attainable with connection of 3620 anodes to set up a natural potential between sacrificial anode and pipeline. Keywords: Cathodic protection, corrosion, impressed current, pipeline, sacrificial anodes ...


    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL


    Since the operation of PS09 SR module in 2007, it has been observed that there is vibration in various parts of the structures, on various segments of piping, and on appurtenance items. At DOT Pipeline and Hazardous Materials Safety Administration (PHMSA) request, ORNL Subject Matter Experts support PHMSA in its review and analysis of the observed vibration phenomenon. The review and analysis consider possible effects of pipeline design features, vibration characteristics, machinery configuration, and operating practices on the structural capacity and leak tight integrity of the pipeline. Emphasis is placed on protection of welded joints and machinery against failure from cyclic loading. A series of vibration measurements were carried out by the author during the site visit to PS09, the power of the operating pump during the data collection is at about 2970KW, which is less than that of APSC's vibration data collected at 3900KW. Thus, a first order proportional factor of 4900/2970 was used to project the measured velocity data to that of APSC's measurement of the velocity data. It is also noted here that the average or the peak-hold value of the measured velocity data was used in the author's reported data, and only the maximum peak-hold data was used in APSC's reported data. Therefore, in some cases APSC's data is higher than the author's projective estimates that using the average data. In general the projected velocity data are consistent with APSC's measurements; the examples of comparison at various locations are illustrated in the Table 1. This exercise validates and confirms the report vibration data stated in APSC's summary report. After the reinforcement project for PS09 Station, a significant reduction of vibration intensity was observed for the associated pipelines at the SR Modules. EDI Co. provided a detailed vibration intensity investigation for the newly reinforced Pump Module structures and the associated

  18. Electrochemical Investigation of the Corrosion of Different Microstructural Phases of X65 Pipeline Steel under Saturated Carbon Dioxide Conditions

    Directory of Open Access Journals (Sweden)

    Yuanfeng Yang


    Full Text Available The aim of this research was to investigate the influence of metallurgy on the corrosion behaviour of separate weld zone (WZ and parent plate (PP regions of X65 pipeline steel in a solution of deionised water saturated with CO2, at two different temperatures (55 °C and 80 °C and at initial pH~4.0. In addition, a non-electrochemical immersion experiment was also performed at 80 °C in CO2, on a sample portion of X65 pipeline containing part of a weld section, together with adjacent heat affected zones (HAZ and parent material. Electrochemical impedance spectroscopy (EIS was used to evaluate the corrosion behaviour of the separate weld and parent plate samples. This study seeks to understand the significance of the different microstructures within the different zones of the welded X65 pipe in CO2 environments on corrosion performance; with particular attention given to the formation of surface scales; and their composition/significance. The results obtained from grazing incidence X-ray diffraction (GIXRD measurements suggest that, post immersion, the parent plate substrate is scale free, with only features arising from ferrite (α-Fe and cementite (Fe3C apparent. In contrast, at 80 °C, GIXRD from the weld zone substrate, and weld zone/heat affected zone of the non-electrochemical sample indicates the presence of siderite (FeCO3 and chukanovite (Fe2CO3(OH2 phases. Scanning Electron Microscopy (SEM on this surface confirmed the presence of characteristic discrete cube-shaped crystallites of siderite together with plate-like clusters of chukanovite.

  19. Customer service drives pipelines` reorganization

    Energy Technology Data Exchange (ETDEWEB)

    Share, J.


    The concept behind formation of Enron Transportation and Storage tells plenty about this new gas industry. When executives at the Enron Gas Pipeline Group considered plans last year to streamline operations by merging the support functions of Transwestern Pipeline and their other wholly owned pipeline company, Northern Natural Gas, seamless customer service was foremost on their agenda. Instead of worrying about whether employees would favor one pipeline over the other, perhaps to the detriment of customers, they simply created a new organization that everyone would swear the same allegiance to. The 17,000-mile, 4.1 Bcf/d Northern system serves the upper Midwest market and two major expansion projects were completed there last year. Transwestern is a 2,700-mile system with an eastward capacity of 1 Bcf/d and westward of 1.5 Bcf/, that traditionally served California markets. It also ties into Texas intrastate markets and, thanks to expansion of the San Juan lateral, to southern Rocky Mountain supplies. Although Enron Corp. continues to position itself as a full-service energy company, the Gas Pipeline Group continues to fuel much of corporate`s net income, which was $584 million last year. With ET and S comprising a significant portion of GPG`s income, it was vital that the merger of Northern`s 950 employees with Transwestern`s 250 indeed be a seamless one. It was not easy either psychologically or geographically with main offices in Omaha, NE and Houston as well as operations centers in Minneapolis, MN; Amarillo, TX; W. Des Moines, IA; and Albuquerque, NM. But the results have been gratifying, according to William R. Cordes, President of ET and S and Nancy L. Gardner, Executive Vice President of Strategic Initiatives.

  20. Gas Metal Arc Welding. Welding Module 5. Instructor's Guide. (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching an eight-unit module in gas metal arc welding. The module is part of a welding curriculum that has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The following topics are covered in the module: safety and testing, gas metal arc…

  1. Circumferential welding of API X80 steel pipes; Soldagem circunferencial em tubos de aco da classe API X80

    Energy Technology Data Exchange (ETDEWEB)

    Castello Branco, J.F.; Bott, Ivani de S. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia]. E-mails:;; Fedele, R.A. [Boehler Thyssen Welding, Sao Paulo, SP (Brazil)]. E-mail:; Souza, Luis Felipe G. de [Centro Federal de Educacao Tecnologica Celso Suckow da Fonseca (CEFET-RJ), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Industrial Mecanica]. E-mail:


    The present work is a part of an extensive program for the development of API 5L Gr.X80 grade steel , produced by the well-known UOE production process, for pipeline fabrication. The current stage of this program involves the characterization and performance evaluation/qualification of girth welds produced by Shield Metal Arc Weld (SMAW) under simulated field conditions, with tubes fixed in the horizontal position. Three types of electrodes were utilized for the basic tasks; the root pass, the hot pass and fill and cap passes. The root pass was carried out with an E-6010 electrode to avoid incomplete joint penetration. The hot pass, applied over the root pass, was performed with an E-9010-G electrode. The fill and cap passes were executed with E-10018-G electrodes. The welded joints produced were evaluated according to the API 1104 specification, which requires: side bend, nick- break and tensile tests. Additionally, non-destructive tests, Charpy-V impact tests and metallographic characterization were undertaken. It was verified that this welding procedure, based on three types of electrodes, could produce welded joints in accordance to the API 1104 specification. These results ensure the applicability of the API 5L Gr. X80 steel developed in this research project for use in pipeline construction. (author)


    Energy Technology Data Exchange (ETDEWEB)

    Wilkowski, Gery M.; Rudland, David L.; Shim, Do-Jun; Brust, Frederick W.; Babu, Sundarsanam


    The potential to save trillions of BTU’s in energy usage and billions of dollars in cost on an annual basis based on use of higher strength steel in major oil and gas transmission pipeline construction is a compelling opportunity recognized by both the US Department of Energy (DOE). The use of high-strength steels (X100) is expected to result in energy savings across the spectrum, from manufacturing the pipe to transportation and fabrication, including welding of line pipe. Elementary examples of energy savings include more the 25 trillion BTUs saved annually based on lower energy costs to produce the thinner-walled high-strength steel pipe, with the potential for the US part of the Alaskan pipeline alone saving more than 7 trillion BTU in production and much more in transportation and assembling. Annual production, maintenance and installation of just US domestic transmission pipeline is likely to save 5 to 10 times this amount based on current planned and anticipated expansions of oil and gas lines in North America. Among the most important conclusions from these studies were: • While computational weld models to predict residual stress and distortions are well-established and accurate, related microstructure models need improvement. • Fracture Initiation Transition Temperature (FITT) Master Curve properly predicts surface-cracked pipe brittle-to-ductile initiation temperature. It has value in developing Codes and Standards to better correlate full-scale behavior from either CTOD or Charpy test results with the proper temperature shifts from the FITT master curve method. • For stress-based flaw evaluation criteria, the new circumferentially cracked pipe limit-load solution in the 2007 API 1104 Appendix A approach is overly conservative by a factor of 4/π, which has additional implications. . • For strain-based design of girth weld defects, the hoop stress effect is the most significant parameter impacting CTOD-driving force and can increase the crack

  3. [New welding processes and health effects of welding]. (United States)

    La Vecchia, G Marina; Maestrelli, Piero


    This paper describes some of the recent developments in the control technology to enhance capability of Pulse Gas Metal Arc Welding. Friction Stir Welding (FSW) processing has been also considered. FSW is a new solid-state joining technique. Heat generated by friction at the rotating tool softens the material being welded. FSW can be considered a green and energy-efficient technique without deleterious fumes, gas, radiation, and noise. Application of new welding processes is limited and studies on health effects in exposed workers are lacking. Acute and chronic health effects of conventional welding have been described. Metal fume fever and cross-shift decline of lung function are the main acute respiratory effects. Skin and eyes may be affected by heat, electricity and UV radiations. Chronic effects on respiratory system include chronic bronchitis, a benign pneumoconiosis (siderosis), asthma, and a possible increase in the incidence of lung cancer. Pulmonary infections are increased in terms of severity, duration, and frequency among welders.

  4. Modeling Stress-Strain State in Butt-Welded Joints after TIG Welding

    Directory of Open Access Journals (Sweden)

    V. Atroshenko


    Full Text Available In this paper mathematical model was developed for definition of thermal-welding cycle influence on welding deformations distribution in flat samples of austenitic steels after TIG welding and developed recommendations to reduce the welding deformation on o the machinery for welding with a copper backing.

  5. Upstream pipelines : inspection, corrosion and integrity management

    Energy Technology Data Exchange (ETDEWEB)

    Paez, J.; Stephenson, M. [Talisman Energy Inc., Calgary, AB (Canada)] (comps.)


    Accurate inspection techniques are needed to ensure the integrity of pipelines. This working group discussed methods of reducing pipeline failures for a variety of pipes. A summary of recent pipeline performance statistics was presented, as well as details of third party damage and fiberglass pipe failures. A batch inhibitor joint industry project was described. The session demonstrated that integrity program need to be developed at the field-level as well as at the upper management level. Fiberglass pipeline failures are significant problem for pipeline operators. Corrosion monitoring, pigging and specific budgets are needed in order to ensure the successful management of pipeline integrity. New software developed to predict pipeline corrosion rates was discussed, and methods of determining mole fractions and flow regimes were presented. The sessions included updates from regulators and standards agencies as well as discussions of best practices, regulations, codes and standards related to pipeline integrity. The working group was divided into 4 sessions: (1) updates since 2007 with input from the Canadian Association of Petroleum Producers (CAPP) and the Upstream Pipeline Integrity Management Association (UPIMA); (2) integrity of non-metallic pipelines; (3) upstream pipeline integrity issues; and (4) hot topics. tabs., figs.

  6. Oil pipeline valve automation for spill reduction

    Energy Technology Data Exchange (ETDEWEB)

    Mohitpour, Mo; Trefanenko, Bill [Enbridge Technology Inc, Calgary (Canada); Tolmasquim, Sueli Tiomno; Kossatz, Helmut [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)


    Liquid pipeline codes generally stipulate placement of block valves along liquid transmission pipelines such as on each side of major river crossings where environmental hazards could cause or are foreseen to potentially cause serious consequences. Codes, however, do not stipulate any requirement for block valve spacing for low vapour pressure petroleum transportation, nor for remote pipeline valve operations to reduce spills. A review of pipeline codes for valve requirement and spill limitation in high consequence areas is thus presented along with a criteria for an acceptable spill volume that could be caused by pipeline leak/full rupture. A technique for deciding economically and technically effective pipeline block valve automation for remote operation to reduce oil spilled and control of hazards is also provided. In this review, industry practice is highlighted and application of the criteria for maximum permissible oil spill and the technique for deciding valve automation thus developed, as applied to ORSUB pipeline is presented. ORSUB is one of the three initially selected pipelines that have been studied. These pipelines represent about 14% of the total length of petroleum transmission lines operated by PETROBRAS Transporte S.A. (TRANSPETRO) in Brazil. Based on the implementation of valve motorization on these three pipeline, motorization of block valves for remote operation on the remaining pipelines is intended, depending on the success of these implementations, on historical records of failure and appropriate ranking. (author)

  7. Russia: the pipeline diplomacy; Russie: la diplomatie du pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Bourdillon, Y


    First world producer of oil and gas, Russia wishes to use its mastery of energy distribution to recover its great power status. The oil and gas pipelines network is the basement used by Russia to build up its hegemony in Europe. The Russian oil and gas companies are also carrying out a long-term strategy of international expansion, in particular thanks to investments in the neighboring countries for the building of new infrastructures or the purchase of oil refineries. (J.S.)

  8. Welding--Trade or Profession? (United States)

    Albright, C. E.; Smith, Kenneth


    This article discusses a collaborative program between schools with the purpose of training and providing advanced education in welding. Modern manufacturing is turning to automation to increase productivity, but it can be a great challenge to program robots and other computer-controlled welding and joining systems. Computer programming and…

  9. Metal Working and Welding Operations. (United States)

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by metal workers and welders. Addressed in the six individual units of the course are the following topics: weldable metals and their alloys, arc welding, gas welding,…

  10. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.


    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. Th...

  11. 29 CFR 1910.255 - Resistance welding. (United States)


    ... 29 Labor 5 2010-07-01 2010-07-01 false Resistance welding. 1910.255 Section 1910.255 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.255 Resistance welding. (a.... Ignitron tubes used in resistance welding equipment shall be equipped with a thermal protection switch. (3...

  12. 46 CFR 154.660 - Pipe welding. (United States)


    ... 46 Shipping 5 2010-10-01 2010-10-01 false Pipe welding. 154.660 Section 154.660 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.660 Pipe welding. (a) Pipe welding must meet Part 57 of this chapter. (b) Longitudinal butt welds...

  13. 49 CFR 179.300-9 - Welding. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.300-9 Section 179.300-9... Specifications for Multi-Unit Tank Car Tanks (Classes DOT-106A and 110AW) § 179.300-9 Welding. (a) Longitudinal... fusion welded on class DOT-110A tanks. Welding procedures, welders and fabricators must be approved in...


    DEFF Research Database (Denmark)


    The invention relates to laser welding of at least two adjacent, abutting or overlapping work pieces in a welding direction using multiple laser beams guided to a welding region, wherein at least two of the multiple laser beams are coupled into the welding region so as to form a melt and at least...

  15. Magnetic Deflection Of Welding Electron Beam (United States)

    Malinzak, R. Michael; Booth, Gary N.


    Electron-beam welds inside small metal parts produced with aid of magnetic deflector. Beam redirected so it strikes workpiece at effective angle. Weld joint positioned to where heavy microfissure concentration removed when subsequent machining required, increasing likelihood of removing any weld defects located in face side of electron-beam weld.

  16. Clamp and Gas Nozzle for TIG Welding (United States)

    Gue, G. B.; Goller, H. L.


    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  17. Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures


    Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen; Guerrero-Mata, Martha Patricia


    In the offshore industry, welding-induced distortion and tensile residual stresses have become a major concern in relation to the structural integrity of a welded structure. Particularly, the continuous increase in size of welded plates and joints needs special attention concerning welding induced residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature fail...

  18. Research on stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater (United States)

    Zou, Y.; Bai, Q.; Dong, S.; Yang, Z. L.; Gao, Y.


    The stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater was studied. Microstructure, mechanical property and stress corrosion cracking susceptibility of the underwater wet welding joint were analyzed by metallographic observation, tensile and bending tests, slow strain rate test (SSRT) and SEM. The results indicated that the weld zone (WZ) and the heat affected zone (HAZ) were all sensitive to the stress corrosion, and the WZ was more sensitive than the HAZ.

  19. Research on the Effects of Technical Parameters on the Molding of the Weld by A-TIG Welding


    Shi, Kai; Pan, Wu


    The effects of welding parameters on the molding of weld by A-TIG welding of a 4mm thickness mild steel plate is studied in the present paper. The results obtained show that: as welding current increases A-TIG welding penetration gets deeper than TIG welding; size and shape of HAZ has remarkable change; A-TIG welding has the narrower weld pool width than TIG welding.

  20. Analytic prognostic for petrochemical pipelines

    CERN Document Server

    Jaoude, Abdo Abou; El-Tawil, Khaled; Noura, Hassan; Ouladsine, Mustapha


    Pipelines tubes are part of vital mechanical systems largely used in petrochemical industries. They serve to transport natural gases or liquids. They are cylindrical tubes and are submitted to the risks of corrosion due to high PH concentrations of the transported liquids in addition to fatigue cracks due to the alternation of pressure-depression of gas along the time, initiating therefore in the tubes body micro-cracks that can propagate abruptly to lead to failure. The development of the prognostic process for such systems increases largely their performance and their availability, as well decreases the global cost of their missions. Therefore, this paper deals with a new prognostic approach to improve the performance of these pipelines. Only the first mode of crack, that is, the opening mode, is considered.

  1. Exchanger system for anhydrite pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Penet, A.


    This paper deals with the problem of roadway behaviour affecting airways, bottom roads and top roads in advancing faces in the HBNPC area. The support work in these zones used to be undertaken manually and involved a lot of man hours. These operations are now mechanized in the form of pneumatic stowing with anhydrite. The latter is delivered by pipeline using compressed air. The 'exchanger' is a sort of branching system in the pipeline enabling the flow to be switched from the top end of the face to the bottom end and vice versa (diagram). The associated operations can be undertaken with ease. The effect the system has on costs will soon be known. (In French)

  2. Automatic welding of stainless steel tubing (United States)

    Clautice, W. E.


    The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

  3. Automatic welding systems for large ship hulls (United States)

    Arregi, B.; Granados, S.; Hascoet, JY.; Hamilton, K.; Alonso, M.; Ares, E.


    Welding processes represents about 40% of the total production time in shipbuilding. Although most of the indoor welding work is automated, outdoor operations still require the involvement of numerous operators. To automate hull welding operations is a priority in large shipyards. The objective of the present work is to develop a comprehensive welding system capable of working with several welding layers in an automated way. There are several difficulties for the seam tracking automation of the welding process. The proposed solution is the development of a welding machine capable of moving autonomously along the welding seam, controlling both the position of the torch and the welding parameters to adjust the thickness of the weld bead to the actual gap between the hull plates.



    Karch, Lukáš; Varga, Augustín


    This paper focuses on the idea of a new European gas pipeline project called Eastring promoted by company Eustream. Eustream is the Slovak gas transmission system operator and has been one of the key players in European gas transmission from Russia to Europe in the last decades. Previous Russian-Ukrainian crisis resulted in reviewing gas flow directions from Russia to Europe in order to enhance the security of gas supplies to Europe. Russia plans to stop gas transmission to Europe via Ukraine...

  5. Design and Implementation of Mobile Robotic Manipulator for Welding Using PLC

    Directory of Open Access Journals (Sweden)

    Nitin TOM


    Full Text Available Robotics is a rapidly growing field in the area of science and technology. With the growth of industrialization and automation one requires a better precision of work with improved productivity and less expenditure. It has reduced additional effort of production line though; it reduces man power and provides faster response as well as better precision of working. It has become the vital sector for all automobile industries specializing in the works considered to be difficult such as welding and assembly. In this work, we have been implemented a mobile robotic manipulator for welding using programmable logic controller (PLC. A manipulator with two links is designed to move in horizontal and vertical directions. The end effector is provided with ac supplied welding torch. The manipulator is made movable with the help of microcontroller based line follower. This paper gives the idea how efficiently welding can be done by synchronizing PLC and microcontroller. PLC is an added advantage to this work as almost all the industries are automated which thereby prevents the installation of new PLC for the proposed system. This manipulator along with sensors can be used to detect the cracks or damages in underground pipelines. It can also be used to weld the corroded furnace or bins in steel or cement plants.

  6. Methodological development and characterization of welded joints in Poly (vinylidene fluoride) (PVDF); Desenvolvimento metodologico e caracterizacao de juntas soldadas de PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Cedrola, S.M.L.; Costa, M.F. da; Pasqualino, I.P., E-mail: samanta@metalmat.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)


    Pipelines are of great concern in the transport sector of oil and gas industries, mainly due to the natural internal aging process caused by contact with the different transported fluids. Installation of polymeric pipes called liners is a good option for rehabilitation of long segments of deteriorated pipelines. Among the potential materials for such application is Poly (vinylidene fluoride) (PVDF). Meanwhile the installation process cannot be carried out in one single step and the polymeric pipe must be cut in sections that are welded during the installation process. In this research welding methodology was studied aiming to optimize welding conditions and the mechanical properties of the joined materials. The first step was processing the PVDF via compression molding on different conditions. Then, the sample was cut and butt-welded. Welding parameters such as, time control, temperature and contact pressure were studied. Afterwards, the stress-strain properties of the welded material was evaluated and physical characterization was carried by x-ray diffraction (DRX). (author)

  7. Pipeline purging principles and practice

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.E.; Svedeman, S.J.; Kuhl, C.A. [Southwest Research Inst., San Antonio, TX (United States); Gregor, J.G. [Gas Research Inst., Chicago, IL (United States); Lambeth, A.K. [Texas Eastern Transmission Corp., Houston, TX (United States)


    Gas purging, a process of displacing one gas by another gas, occurs on a routine basis in the natural gas industry when pipelines are purged into and out of service. In a project sponsored by the Gas Research Institute and in cooperation with the American Gas Association (A.G.A.) the purging practices as outlined in the A.G.A.`s Purging Principles and Practices manual are being reviewed because many of today`s pipeline purging operations occur under conditions not addressed directly in the manual. The program focus is on the purging procedures outlined in Chapter 8 of the manual entitled Gas Transmission and Distribution pipes. The technical objective of the project is to develop an understanding of the scientific principles upon which safe, practical purging practices can be based. Direct displacement and inert gas slug purging operations are explained in terms of dispersion and mixing parameters and their relationship to the gas velocity. Field data is compared to the results of an analytical mixing model. Computer software for planning safe and cost effective pipeline purges has been developed. Finally, recommendations for revising Chapter 8 of the A.G.A. manual are presented.

  8. Shore approach of Camarupim pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, Tiaraju P.; Oliveira Neto, Vasco A. de; Siqueira, Jakson [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)


    Camarupim Field is located in the northern portion of Espirito Santo Basin and was discovered from the drilling of the well 1-ESS-164 in 2006. It is a gas field which start of the production is in mid of 2009. The production unit will be a FPSO (Floating Production, Storage and Offloading) and the gas will flow through a pipeline with diameter ranging from 12 inches and 24 inches with approximately 60 km long, from the FPSO Cidade de Sao Mateus to UTGC (Unit for Treatment of Gas Cacimbas-Linhares-ES). The FPSO will have processing capacity of 10MMm3/day of gas. Due to the approach of the pipeline in the continental portion, located in an environmental protection area and place of spawning of sea turtles, the connection between the stretch of sea and land pipeline running through a shore approach, known and proven technique of horizontal directional drilling about 950m in length. This paper will be shown the assumptions adopted, the technique employed, the challenges faced by the team and the lessons learned to build the directional hole. (author)

  9. Microstructure and Mechanical Properties of an Ultrasonic Spot Welded Aluminum Alloy: The Effect of Welding Energy

    National Research Council Canada - National Science Library

    He Peng; Daolun Chen; Xianquan Jiang


    The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique-ultrasonic spot welding (USW...

  10. Versatile Friction Stir Welding/Friction Plug Welding System (United States)

    Carter, Robert


    A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

  11. Real time computer controlled weld skate (United States)

    Wall, W. A., Jr.


    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  12. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove


    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  13. Control of Welding Processes. (United States)


    Structures, Office of Deputy Under Secretary of Defense for R&E (ET), Department of Defense, Washington, D.C. CHARLES ZANIS, Assistant Director for Platform... CHARLES NULL, Head, Metals Branch, Naval Sea Systems Command, Washington, D.C. ROBERT A. WEBER, Welding Engineering and Metallurgy, U.S. Army Corps of...Needs. Pp. 487-90. in Papers Presented at the August 3-8, 1Q80, AIME Syi,.posium. Essers, W . ., and R. Walter. Heat transfer and penet ration

  14. The effect of friction welding self-regulation process on weld structure and hardness

    Directory of Open Access Journals (Sweden)

    W. Ptak


    Full Text Available The self-regulation phenomenon that occurs during friction welding process was characterised, and the effect of the self-regulation of theenergy-related parameters on structure and hardness distribution in SW7Mo steel – 55 steel welded joint was determined experimentally.The structure and hardness of the weld zone were examined, the energy required for the stable run of a friction welding process wascalculated, and a relationship between the welding energy and weld hardness was derived.

  15. 10,170 flawless welds

    CERN Multimedia

    Antonella Del Rosso


    The welding of tubes containing the principal current-carrying busbars in the LHC magnets was one of the main activities of the SMACC project. After a year of preparation and another of intense activity in the tunnel, the last weld was completed on Wednesday 14 May. Over 10,170 welds have been inspected and not a single fault has been found.    The welder (above) creates the weld using an orbital welding machine (below) specifically designed for CERN. Each of the eight sectors of the LHC contains around 210 interconnects between the superconducting magnets. Consolidating these interconnections was the SMACC project’s primary objective. One of the last jobs before closing the interconnects is the welding of the M lines: each has a 104 mm diameter and a radial clearance of just 45 mm. In total: 10,170 welds carried out in a single year of activities. A true challenge, which was carried out by a team of 30 highly specialised welders, working under the supervision o...

  16. Laser welding of fused quartz (United States)

    Piltch, Martin S.; Carpenter, Robert W.; Archer, III, McIlwaine


    Refractory materials, such as fused quartz plates and rods are welded using a heat source, such as a high power continuous wave carbon dioxide laser. The radiation is optimized through a process of varying the power, the focus, and the feed rates of the laser such that full penetration welds may be accomplished. The process of optimization varies the characteristic wavelengths of the laser until the radiation is almost completely absorbed by the refractory material, thereby leading to a very rapid heating of the material to the melting point. This optimization naturally occurs when a carbon dioxide laser is used to weld quartz. As such this method of quartz welding creates a minimum sized heat-affected zone. Furthermore, the welding apparatus and process requires a ventilation system to carry away the silicon oxides that are produced during the welding process to avoid the deposition of the silicon oxides on the surface of the quartz plates or the contamination of the welds with the silicon oxides.

  17. The technology and welding joint properties of hybrid laser-tig welding on thick plate (United States)

    Shenghai, Zhang; Yifu, Shen; Huijuan, Qiu


    The technologies of autogenous laser welding and hybrid laser-TIG welding are used on thick plate of high strength lower alloy structural steel 10CrNiMnMoV in this article. The unique advantages of hybrid laser-TIG welding is summarized by comparing and analyzing the process parameters and welding joints of autogenous laser welding laser welding and hybrid laser-TIG welding. With the optimal process parameters of hybrid welding, the good welding joint without visible flaws can be obtained and its mechanical properties are tested according to industry standards. The results show that the hybrid welding technology has certain advantages and possibility in welding thick plates. It can reduce the demands of laser power, and it is significant for lowering the aspect ratio of weld during hybrid welding, so the gas in the molten pool can rise and escape easily while welding thick plates. Therefore, the pores forming tendency decreases. At the same time, hybrid welding enhances welding speed, and optimizes the energy input. The transition and grain size of the microstructure of hybrid welding joint is better and its hardness is higher than base material. Furthermore, its tensile strength and impact toughness is as good as base material. Consequently, the hybrid welding joint can meet the industry needs completely.

  18. Review of laser hybrid welding

    DEFF Research Database (Denmark)

    Bagger, Claus


    In this artucle an overview og the hybrid welding process is given. After a short historic overview, a review of the fundamental phenomenon taking place when a laser (CO2 or Nd:YAG) interacts in the same molten pool as a more conventional source of energy, e.g. tungsten in-active gas, plasma......, or metal inactive gas/metal active gas.This is followed by reports of how the many process parameters governing the hybrid welding process can be set and how the choice of secondary energy source, shielding gas, etc. can affect the overall welding process....

  19. Novel Process Revolutionizes Welding Industry (United States)


    Glenn Research Center, Delphi Corporation, and the Michigan Research Institute entered into a research project to study the use of Deformation Resistance Welding (DRW) in the construction and repair of stationary structures with multiple geometries and dissimilar materials, such as those NASA might use on the Moon or Mars. Traditional welding technologies are burdened by significant business and engineering challenges, including high costs of equipment and labor, heat-affected zones, limited automation, and inconsistent quality. DRW addresses each of those issues, while drastically reducing welding, manufacturing, and maintenance costs.

  20. Convection in arc weld pools

    Energy Technology Data Exchange (ETDEWEB)

    Oreper, G.M.; Eagar, T.W.; Szekely, J.


    A mathematical model was developed to account for convection and temperature distributions in stationary arc weld pools driven by buoyancy, electromagnetic and surface tension forces. It is shown that the electromagnetic and surface tension forces dominate the flow behavior. In some cases, these forces produce double circulation loops, which are indirectly confirmed by experimental measurements of segregation in the weld pool. It is also shown that the surface tension driven flows are very effective in dissipating the incident energy flux on the pool surface which, in turn, reduces the vaporization from the weld pool.

  1. Plasticity Theory of Fillet Welds

    DEFF Research Database (Denmark)

    Hansen, Thomas


    This paper deals with simple methods for calculation of fillet welds based on the theory of plasticity. In developing the solutions the lower-bound theorem is used. The welding material and parts of the base material are subdivided into triangular regions with homogeneous stress fields; thereby...... a safe and statically admissible stress distribution is established. The plasticity solutions are compared with tests carried out at the Engineering Academy of Denmark, Lyngby, in the early nineties, and old fillet weld tests. The new failure conditions are in very good agreement with the yield load...

  2. Specification and qualification of welding procedures for metallic materials : welding procedure test : part 1 : arc and gas welding of steels and arc welding of nickel and nickel alloys : technical corrigendum 1

    CERN Document Server

    International Organization for Standardization. Geneva


    Specification and qualification of welding procedures for metallic materials : welding procedure test : part 1 : arc and gas welding of steels and arc welding of nickel and nickel alloys : technical corrigendum 1

  3. Automated Variable-Polarity Plasma-Arc Welding (United States)

    Numes, A. C., Jr.; Bayless, E. O., Jr.; Jones, S. C., III; Munafo, P.; Munafo, A.; Biddle, A.; Wilson, W.


    Variable-polarity plasma-arc methods produces better welds at lower cost than gas-shielded tungsten-arc welding in assemblies. Weld porosity very low and costs of joint preparation, depeaking, inspection, and weld repair minimized.

  4. Land use planning for pipelines : a guideline for local authorities, developers and pipeline operators

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, S. (ed.) [Canadian Standards Association, Mississauga, ON (Canada)


    This document is intended for local authorities who deal with issues of land regulation and public safety near pipelines. Input was provided by representatives of the pipeline industry, government agencies, municipalities, planners, developers and academics. The document emphasizes the importance of continual communication by key stakeholders to reduce the potential for conflicts and costs, and to ensure that available access is maintained along the pipeline's right-of-way so that pipelines can be constructed, maintained or operated in an efficient manner. This document also outlines the significance of recognizing land uses adjacent to the pipeline right-of-way. It provides guidelines in the following subject areas: (1) roles and responsibilities for key stakeholders, (2) the pipeline industry, (3) products transported in pipelines, (4) land use planning issues regarding pipelines, and (5) sources of additional information. refs., figs.

  5. Laser welding and post weld treatment of modified 9Cr-1MoVNb steel.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z. (Nuclear Engineering Division)


    Laser welding and post weld laser treatment of modified 9Cr-1MoVNb steels (Grade P91) were performed in this preliminary study to investigate the feasibility of using laser welding process as a potential alternative to arc welding methods for solving the Type IV cracking problem in P91 steel welds. The mechanical and metallurgical testing of the pulsed Nd:YAG laser-welded samples shows the following conclusions: (1) both bead-on-plate and circumferential butt welds made by a pulsed Nd:YAG laser show good welds that are free of microcracks and porosity. The narrow heat affected zone has a homogeneous grain structure without conventional soft hardness zone where the Type IV cracking occurs in conventional arc welds. (2) The laser weld tests also show that the same laser welder has the potential to be used as a multi-function tool for weld surface remelting, glazing or post weld tempering to reduce the weld surface defects and to increase the cracking resistance and toughness of the welds. (3) The Vicker hardness of laser welds in the weld and heat affected zone was 420-500 HV with peak hardness in the HAZ compared to 240 HV of base metal. Post weld laser treatment was able to slightly reduce the peak hardness and smooth the hardness profile, but failed to bring the hardness down to below 300 HV due to insufficient time at temperature and too fast cooling rate after the time. Though optimal hardness of weld made by laser is to be determined for best weld strength, methods to achieve the post weld laser treatment temperature, time at the temperature and slow cooling rate need to be developed. (4) Mechanical testing of the laser weld and post weld laser treated samples need to be performed to evaluate the effects of laser post treatments such as surface remelting, glazing, re-hardening, or tempering on the strength of the welds.

  6. Transmission pipeline calculations and simulations manual

    CERN Document Server

    Menon, E Shashi


    Transmission Pipeline Calculations and Simulations Manual is a valuable time- and money-saving tool to quickly pinpoint the essential formulae, equations, and calculations needed for transmission pipeline routing and construction decisions. The manual's three-part treatment starts with gas and petroleum data tables, followed by self-contained chapters concerning applications. Case studies at the end of each chapter provide practical experience for problem solving. Topics in this book include pressure and temperature profile of natural gas pipelines, how to size pipelines for specified f

  7. A quick guide to pipeline engineering

    CERN Document Server

    Alkazraji, D


    Pipeline engineering requires an understanding of a wide range of topics. Operators must take into account numerous pipeline codes and standards, calculation approaches, and reference materials in order to make accurate and informed decisions.A Quick Guide to Pipeline Engineering provides concise, easy-to-use, and accessible information on onshore and offshore pipeline engineering. Topics covered include: design; construction; testing; operation and maintenance; and decommissioning.Basic principles are discussed and clear guidance on regulations is provided, in a way that will

  8. Tubular lining material for pipelines having bends

    Energy Technology Data Exchange (ETDEWEB)

    Moringa, A.; Sakaguchi, Y.; Hyodo, M.; Yagi, I.


    A tubular lining material for pipelines having bends or curved portions comprises a tubular textile jacket made of warps and wefts woven in a tubular form overlaid with a coating of a flexible synthetic resin. It is applicable onto the inner surface of a pipeline having bends or curved portions in such manner that the tubular lining material with a binder onto the inner surface thereof is inserted into the pipeline and allowed to advance within the pipeline, with or without the aid of a leading rope-like elongated element, while turning the tubular lining material inside out under fluid pressure. In this manner the tubular lining material is applied onto the inner surface of the pipeline with the binder being interposed between the pipeline and the tubular lining material. The lining material is characterized in that a part of all of the warps are comprised of an elastic yarn around which, over the full length thereof, a synthetic fiber yarn or yarns have been left-and/or right-handedly coiled. This tubular lining material is particularly suitable for lining a pipeline having an inner diameter of 25-200 mm and a plurality of bends, such as gas service pipelines or house pipelines, without occurrence of wrinkles in the lining material in a bend.

  9. Study on the correlation of toughness with chemical composition and tensile test results in microalloyed API pipeline steels

    Directory of Open Access Journals (Sweden)

    Pouraliakbar H.


    Full Text Available In this investigation, an artificial neural network model with feed forward topology and back propagation algorithm was developed to predict the toughness (area underneath of stress-strain curve of high strength low alloy steels. The inputs of the neural network included the weight percentage of 15 alloying elements and the tensile test results such as yield strength, ultimate tensile strength and elongation. Developing the model, 118 different steels from API X52 to X70 grades were used. The developed model was validated with 26 other steels from the data set that were not used for the model development. Additionally, the model was also employed to predict the toughness of 26 newly tested steels. The predicted values were in very good agreement with the measured ones indicating that the developed model was very accurate and had the great ability for predicting the toughness of pipeline steels.

  10. Materials participation in welded joints manufacturing (United States)

    Ghenghea, L. D.


    Management of materials dilution to form a joint with higher features asked by complex metallic structures is a problem that took attention and efforts of welding processes researchers and this communication will give a little contribution presenting some scientific and experimental results of dilution processes studied by Welding Research Group from Iasi, Romania, TCM Department. Liquid state welding processes have a strong dependence related to dilution of base and filler materials, the most important are for automatic joining using welding. The paper presents a review of some scientific works already published and their contributions, results of dilution coefficient evaluation using weighing, graphics and software applied for shielded metal arc welding process. Paper results could be used for welders’ qualification, welding procedure specification and other welding processes researchers’ activities. The results of Welding Research Group from Iasi, Romania, TCM Department, show dilution coefficient values between 20-30 % of base material and 70-80 % of filler material for studied welding process.

  11. Filler wire for aluminum alloys and method of welding (United States)

    Bjorkman, Jr., Gerald W. O. (Inventor); Cho, Alex (Inventor); Russell, Carolyn K. (Inventor)


    A weld filler wire chemistry has been developed for fusion welding 2195 aluminum-lithium. The weld filler wire chemistry is an aluminum-copper based alloy containing high additions of titanium and zirconium. The additions of titanium and zirconium reduce the crack susceptibility of aluminum alloy welds while producing good weld mechanical properties. The addition of silver further improves the weld properties of the weld filler wire. The reduced weld crack susceptibility enhances the repair weldability, including when planishing is required.

  12. MFDC - technological improvement in resistance welding controls

    Energy Technology Data Exchange (ETDEWEB)

    Somani, A.K.; Naga Bhaskar, V.; Chandramouli, J.; Rameshwara Rao, A. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)


    Among the various Resistance Welding operations carried out in the production line of a fuel bundle end plug welding is the most critical operation. Welding controllers play a very vital role in obtaining consistent weld quality by regulating and controlling the weld current. Conventional mains synchronized welding controllers are at best capable of controlling the weld current at a maximum speed of the mains frequency. In view of the very short welding durations involved in the various stages of a fuel bundle fabrication, a need was felt for superior welding controllers. Medium Frequency Welding Controllers offer a solution to these limitations in addition to offering other advantages. Medium Frequency power sources offer precise welding current control as they regulate and correct the welding current faster, typically twenty times faster when operated at 1000Hz. An MFDC was employed on one of the welding machines and its performance was studied. This paper discusses about the various advantages of MFDCs with other controllers employed at NFC to end plug welding operation. (author)

  13. Gas Shielding Technology for Welding and Brazing (United States)

    Nunes, Arthur J.; Gradl, Paul R.


    Welding is a common method that allows two metallic materials to be joined together with high structural integrity. When joints need to be leak-tight, light-weight, or free of contaminant-trapping seams or surface asperities, welding tends to be specified. There are many welding techniques, each with its own advantages and disadvantages. Some of these techniques include Forge Welding, Gas Tungsten Arc Welding, Friction Stir Welding, and Laser Beam Welding to name a few. Whichever technique is used, the objective is a structural joint that meets the requirements of a particular component or assembly. A key practice in producing quality welds is the use of shielding gas. This article discusses various weld techniques, quality of the welds, and importance of shielding gas in each of those techniques. Metallic bonds, or joints, are produced when metals are put into intimate contact. In the solid-state "blacksmith welding" process, now called Forge Welding (FOW), the site to be joined is pounded into intimate contact. The surfaces to be joined usually need to be heated to make it easier to deform the metal. The surfaces are sprinkled with a flux to melt surface oxides and given a concave shape so that surface contamination can be squeezed out of the joint as the surfaces are pounded together; otherwise the surface contamination would be trapped in the joint and would weaken the weld. In solid-state welding processes surface oxides or other contamination are typically squeezed out of the joint in "flash."

  14. External coatings for buried pipelines - a project approach; Revestimento externo para dutos enterrados - uma abordagem de projeto

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Laerce de P.; Gomes, Luiz Paulo; Nunes, Alessandra de M. [IEC - Instalacoes e Engenharia de Corrosao Ltda., Rio de Janeiro, RJ (Brazil)


    The transport of liquid or gas fluids, such as water, fuel, chemical products, minerals, among others, through underground pipelines, is becoming more significant in the whole world, specially in Brazil, due to low cost, operational security and low physical interference at the surface. By the other hand, the ambient matters, the population's security in pipeline tracing and economic aspects lead to greater requirements in relation to the integrity of those installations. Corrosion is one of the most important causes of underground pipelines' deterioration and coating and cathodic protection are recommended to prevent it from occurring. However, both techniques must be considered in the pipeline project for it to be successful. At the present work the most important kinds of coating for underground pipelines are presented, as well as the applications, limitations, reference norms and the interface with the cathodic protection systems in relation to the efficiencies to be adopted and the expected performance. Is it also discussed the welded piping joints confection and the protection difficulties when the efficiencies are not corresponded to those foreseen in the cathodic protection systems project. (author)

  15. 77 FR 45417 - Pipeline Safety: Inspection and Protection of Pipeline Facilities After Railway Accidents (United States)


    ..., depth and location of the pipelines so that the movement of heavy equipment and debris on the right-of... the presence, depth and location of the pipelines so that the movement of heavy equipment on the right... cover permitted by the current Federal and industry pipeline construction standards, it likely would...

  16. Addressing the workforce pipeline challenge

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond; Kevin Kostelnik; Richard Holman


    A secure and affordable energy supply is essential for achieving U.S. national security, in continuing U.S. prosperity and in laying the foundations to enable future economic growth. To meet this goal the next generation energy workforce in the U.S., in particular those needed to support instrumentation, controls and advanced operations and maintenance, is a critical element. The workforce is aging and a new workforce pipeline, to support both current generation and new build has yet to be established. The paper reviews the challenges and some actions being taken to address this need.

  17. Welding and Production Metallurgy Facility (United States)

    Federal Laboratory Consortium — This 6000 square foot facility represents the only welding laboratory of its kind within DA. It is capable of conducting investigations associated with solid state...

  18. Thermomechanical Modelling of Resistance Welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi


    The present paper describes a generic programme for analysis, optimization and development of resistance spot and projection welding. The programme includes an electrical model determining electric current and voltage distribution as well as heat generation, a thermal model calculating heat...

  19. Laser Welding of Ship Steel

    National Research Council Canada - National Science Library

    Brayton, W. C; Banas, C. M; Peters, G. T


    ... joint cleanliness and fitup conditions. In the current program, welds were formed between surfaces with nonperfect fitup, between plasma-cut surfaces, between surfaces deliberately mismatched to provide a varging joint gap and under out...

  20. Welding process modelling and control (United States)

    Romine, Peter L.; Adenwala, Jinen A.


    The research and analysis performed, and software developed, and hardware/software recommendations made during 1992 in development of the PC-based data acquisition system for support of Welding Process Modeling and Control is reported. A need was identified by the Metals Processing Branch of NASA Marshall Space Flight Center, for a mobile data aquisition and analysis system, customized for welding measurement and calibration. Several hardware configurations were evaluated and a PC-based system was chosen. The Welding Measurement System (WMS) is a dedicated instrument, strictly for the use of data aquisition and analysis. Although the WMS supports many of the functions associated with the process control, it is not the intention for this system to be used for welding process control.

  1. Automatic Control Of Length Of Welding Arc (United States)

    Iceland, William F.


    Nonlinear relationships among current, voltage, and length stored in electronic memory. Conceptual microprocessor-based control subsystem maintains constant length of welding arc in gas/tungsten arc-welding system, even when welding current varied. Uses feedback of current and voltage from welding arc. Directs motor to set position of torch according to previously measured relationships among current, voltage, and length of arc. Signal paths marked "calibration" or "welding" used during those processes only. Other signal paths used during both processes. Control subsystem added to existing manual or automatic welding system equipped with automatic voltage control.

  2. Effect of deposit composition on the mechanical properties and cracking tendency of cellulosic-covered SMAW weld deposits

    Energy Technology Data Exchange (ETDEWEB)

    James, Matthew J.; Weaver, Robert J.; Quintana, Marie A.; Savrin, Tamara [The Lincoln Electric Company, Cleveland, Ohio, (United States)


    Boron is a concern in the pipeline industry, where its propensity to cause cracking is a concern. The goal of this study is to quantify the effect of changes in deposit composition - specifically boron and Pcm on the properties of cellulosic weld deposits. Four trial electrodes with different concentrations of boron were tested. One, in which the boron was replaced by the same amount of carbon, is the reference test specimen without boron. Gapped bead on plate testing was used to determine the propensity of the electrodes for weld metal cracking. The results do not provide a clear picture of the influence of boron. Replacing boron with carbon showed very slight differences. In most trials, the effect of boron was not found to be significant. In the case of hydrogen assisted cold cracking (HACC), other factors should be investigated but removing the boron is not enough to reduce the sensitivity of cellulosic weld metal to cracking.

  3. Ship construction and welding

    CERN Document Server

    Mandal, Nisith R


    This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters. The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures. With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and form...

  4. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.


    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  5. Oil and Natural Gas Pipelines, North America, 2010, Platts (United States)

    U.S. Environmental Protection Agency — The Oil and Natural Gas Pipeline geospatial data layer contains gathering, interstate, and intrastate natural gas pipelines, crude and product oil pipelines, and...

  6. Lietuvos Dujos. Report on project execution and finalisation. Inspection of pipelines, phase 2

    Energy Technology Data Exchange (ETDEWEB)



    Danish government funds were released in July 1995 for the project `Inspection of Pipelines in Lithuania, Phase 2`. However, since a previous inspection project, carried out during 1995 was not yet completed, it was decided, and accepted by `Energistyrelsen`, to postpone the onset of the Phase 2 project till the 1995 Project was finalised. In connection with the Final Project Meeting of the 1995 Project, held 4. and 5. January 1996, the Phase 2 project was kicked off. Following a request from Lietuvos Dujos, the Phase 2 activities were subdivided into two relatively independent subprojects, viz. the Inspection of 28 km of a New Panevezys-Siauliai Pipeline, and the CP Equipment, Training and Systematic Maintenance Programme. The Phase 2 project has been carried out in accordance with the general conditions of the Finance Ministry for sector programmes in Eastern and Central Europe, April 1994, and the letters from `Energistyrelsen` of 6. July 1995, as amended by letters from DONG dated 12. January 1996, and 28. June 1996, and the letter from `Energistyrelsen` dated 3. July 1996. The Inspection of 28 km of a New Panevezys-Siauliai Pipeline has been focusing on the possible reuse of 28 km of pipes supplied and field welded in 1990, prior to the independence of Lithuania. Due to lack of financial resources and the decline of gas consumption immediately after the independence, these pipes had been left in the field, in principle unattended and with incomplete protection against corrosion and other deterioration. Since Lietuvos Dujos now plans to extend its pipeline system, and in this context intends to reuse the 28 km of pipes, an inspection to establish whether the pipes seem to be fit for purpose was necessary. The cathodic protection (CP) part of the project has been focusing on delivery and use of measuring equipment, rectifier stations and tools for cathodic protection work. A training programme has been conducted on an approximately 24 km section of the DN 500

  7. Development of a robotic manipulator for orbital welding; Desenvolvimento de um manipulador robotico para a sondagem orbital

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Renon Steinbach; Dutra, Jair Carlos [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Lab. de Soldagem; Bonacorso, Nelso Gauze [Centro Federal de Educacao Tecnologica de Santa Catarina (CEFET/SC), Florianopolis, SC (Brazil). Lab. da Automacao Hidraulica e Pneumatica (LAHP)


    On the national oil scenario, the pipelines have a high cost, specially on the long time spent on its constructions. Thus, this transaction optimizations become highly attractive. A form of improvement this task is to automate the process of welding. In this context it is interesting the use of a robot manipulator for the orbital welding. In the international market, there are dedicates solutions that meet the restrictions associated mainly with the ease of handling and dimensions. However,since these manipulators use foreign technology this makes the acquisition and maintenance costs high. The project aims to create subsides for greater efficiency in the task of union of pipelines through the development of a robotic manipulator. However it is clear that only the design of such a handler does not guarantee the quality of the root pass. Therefore, it is also being studied the use of the process MIG (Metal Inert Gas), through parametrization of CCC (Short-circuit controlled) in order to have a robust process of welding. The CCC monitors the process of welding and acts when there is detection od short circuit. It is obtained then higher pass from scratch controllability and drastically reduces the amount of spay. (author)

  8. Evaluation of the resistance of API 5L-X80 girth welds to sulphide stress corrosion cracking and hydrogen embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Forero, Adriana [Pontificia Universidade Catolica (PUC-Rio), Rio de Janeiro, RJ (Brazil); Ponciano, Jose A. [Universidade Federal do Rio de Janeiro (COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao em Engenharia; Bott, Ivani de S. [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia


    The susceptibility of pipeline steels to stress corrosion cracking (SCC) depends on a series of factors ranging from the manufacture of the steel, the pipe fabrication and the assembly of the pipeline to the type of substances to be transported. The welding procedures adopted during the production and construction of the pipelines (field welding), can modify the properties of the base metal in the heat affected zone (HAZ), potentially rendering this region susceptible to SCC. This study evaluates the resistance of girth welds, in API 5L X80 pipes, to hydrogen embrittlement and to stress corrosion cracking in the presence of sulphides. The evaluation was performed according to NACE TM0177/96, Method A, applying the criterion of fracture/no fracture, and Slow Strain Rate Tensile tests (SSRT) were undertaken using a sodium thiosulphate solution according to the ASTM G129-00 Standard. According NACE requirements, the base metal was approved. The weld metal exhibited susceptibility to SCC in the presence of sulphides, failing in a period of less than 720h. This was confirmed by SSR tensile tests, where a significant decrease in the ultimate tensile strength, the elongation and the time to fracture were observed. The mechanism of fracture was transgranular. (author)

  9. Anaesthetic machine pipeline inlet pressure gauges do not always measure pipeline pressure. (United States)

    Craig, D B; Longmuir, J


    Some anaesthetic gas machines have pipeline inlet pressure gauges which indicate the higher of either pipeline pressure, or machine circuit pressure (the pressure distal to the pressure reducing valve, and proximal to the flowmeter control valve). Failure by the operator to appreciate this feature may in specific circumstances lead to a delayed appreciation of pipeline malfunction or disconnection. The Canadian Standards Association Z168.3-M1980 Anaesthetic Gas Machine Standard requires pipeline inlet gauges which measure only pipeline (hose) pressure. Existing machines should be modified to accommodate this requirement.

  10. A comparison of the physics of Gas Tungsten Arc Welding (GTAW), Electron Beam Welding (EBW), and Laser Beam Welding (LBW) (United States)

    Nunes, A. C., Jr.


    The physics governing the applicability and limitations of gas tungsten arc (GTA), electron beam (EB), and laser beam (LB) welding are compared. An appendix on the selection of laser welding systems is included.

  11. Upgraded HFIR Fuel Element Welding System

    Energy Technology Data Exchange (ETDEWEB)

    Sease, John D [ORNL


    The welding of aluminum-clad fuel plates into aluminum alloy 6061 side plate tubing is a unique design feature of the High Flux Isotope Reactor (HFIR) fuel assemblies as 101 full-penetration circumferential gas metal arc welds (GMAW) are required in the fabrication of each assembly. In a HFIR fuel assembly, 540 aluminum-clad fuel plates are assembled into two nested annular fuel elements 610 mm (24-inches) long. The welding process for the HFIR fuel elements was developed in the early 1960 s and about 450 HFIR fuel assemblies have been successfully welded using the GMAW process qualified in the 1960 s. In recent years because of the degradation of the electronic and mechanical components in the old HFIR welding system, reportable defects in plate attachment or adapter welds have been present in almost all completed fuel assemblies. In October 2008, a contract was awarded to AMET, Inc., of Rexburg, Idaho, to replace the old welding equipment with standard commercially available welding components to the maximum extent possible while maintaining the qualified HFIR welding process. The upgraded HFIR welding system represents a major improvement in the welding system used in welding HFIR fuel elements for the previous 40 years. In this upgrade, the new inner GMAW torch is a significant advancement over the original inner GMAW torch previously used. The innovative breakthrough in the new inner welding torch design is the way the direction of the cast in the 0.762 mm (0.030-inch) diameter aluminum weld wire is changed so that the weld wire emerging from the contact tip is straight in the plane perpendicular to the welding direction without creating any significant drag resistance in the feeding of the weld wire.

  12. Oil pipeline energy consumption and efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Hooker, J.N.


    This report describes an investigation of energy consumption and efficiency of oil pipelines in the US in 1978. It is based on a simulation of the actual movement of oil on a very detailed representation of the pipeline network, and it uses engineering equations to calculate the energy that pipeline pumps must have exerted on the oil to move it in this manner. The efficiencies of pumps and drivers are estimated so as to arrive at the amount of energy consumed at pumping stations. The throughput in each pipeline segment is estimated by distributing each pipeline company's reported oil movements over its segments in proportions predicted by regression equations that show typical throughput and throughput capacity as functions of pipe diameter. The form of the equations is justified by a generalized cost-engineering study of pipelining, and their parameters are estimated using new techniques developed for the purpose. A simplified model of flow scheduling is chosen on the basis of actual energy use data obtained from a few companies. The study yields energy consumption and intensiveness estimates for crude oil trunk lines, crude oil gathering lines and oil products lines, for the nation as well as by state and by pipe diameter. It characterizes the efficiency of typical pipelines of various diameters operating at capacity. Ancillary results include estimates of oil movements by state and by diameter and approximate pipeline capacity utilization nationwide.

  13. Testing the School-to-Prison Pipeline (United States)

    Owens, Emily G.


    The School-to-Prison Pipeline is a social phenomenon where students become formally involved with the criminal justice system as a result of school policies that use law enforcement, rather than discipline, to address behavioral problems. A potentially important part of the School-to-Prison Pipeline is the use of sworn School Resource Officers…

  14. pipelines cathodic protection design methodologies for impressed ...

    African Journals Online (AJOL)


    total external surface area of 226224m2. The computation further showed the current requirement was attainable with connection of 3620 anodes to set up a natural potential between sacrificial anode and pipeline. Key words: Cathodic protection, corrosion, impressed current, pipeline, sacrificial anodes. 1. INTRODUCTION.

  15. Weld procedure produces quality welds for thick sections of Hastelloy-X (United States)

    Flens, F. J.; Fletcher, C. W.; Glasier, L. F., Jr.


    Welding program produces premium quality, multipass welds in heavy tube sections of Hastelloy-X. It develops semiautomatic tungsten/inert gas procedures, weld wire procurement specifications material weld properties, welder-operator training, and nondestructive testing inspection techniques and procedures.

  16. Laser welding of aluminium-magnesium alloys sheets process optimization and welds characterization

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, C. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France); Fouquet, F. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France); Robin, M. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France)


    The purpose of the present study was to obtain good quality welds using a CO2 laser with Al-Mg alloys sheet. Defects formation mechanisms were analyzed and a welding procedure was defined, using several characterization technics, in order to realize low defects welding seams. After laser welding optimization, comparative tensile tests and microstructural analysis were carried out. (orig.)

  17. Offshore Pipeline Locations in the Gulf of Mexico, Geographic NAD27, MMS (2007) [pipelines_vectors_mms_2007 (United States)

    Louisiana Geographic Information Center — Offshore Minerals Management Pipeline Locations for the Gulf of Mexico (GOM). Contains the lines of the pipeline in the GOM. All pipelines existing in the databases...

  18. Offshore Pipeline Locations in the Gulf of Mexico, Geographic NAD27, MMS (2007) [pipelines_points_mms_2007 (United States)

    Louisiana Geographic Information Center — Offshore Minerals Management Pipeline Locations for the Gulf of Mexico (GOM). Contains the points of the pipeline in the GOM. All pipelines existing in the databases...

  19. Efficiency improvements in pipeline transportation systems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, W. F.; Horton, J. F.


    This report identifies potential energy-conservative pipeline innovations that are most energy- and cost-effective and formulates recommendations for the R, D, and D programs needed to exploit those opportunities. From a candidate field of over twenty classes of efficiency improvements, eight systems are recommended for pursuit. Most of these possess two highly important attributes: large potential energy savings and broad applicability outside the pipeline industry. The R, D, and D program for each improvement and the recommended immediate next step are described. The eight technologies recommended for R, D, and D are gas-fired combined cycle compressor station; internally cooled internal combustion engine; methanol-coal slurry pipeline; methanol-coal slurry-fired and coal-fired engines; indirect-fired coal-burning combined-cycle pump station; fuel-cell pump station; drag-reducing additives in liquid pipelines; and internal coatings in pipelines.

  20. The Hyper Suprime-Cam software pipeline (United States)

    Bosch, James; Armstrong, Robert; Bickerton, Steven; Furusawa, Hisanori; Ikeda, Hiroyuki; Koike, Michitaro; Lupton, Robert; Mineo, Sogo; Price, Paul; Takata, Tadafumi; Tanaka, Masayuki; Yasuda, Naoki; AlSayyad, Yusra; Becker, Andrew C.; Coulton, William; Coupon, Jean; Garmilla, Jose; Huang, Song; Krughoff, K. Simon; Lang, Dustin; Leauthaud, Alexie; Lim, Kian-Tat; Lust, Nate B.; MacArthur, Lauren A.; Mandelbaum, Rachel; Miyatake, Hironao; Miyazaki, Satoshi; Murata, Ryoma; More, Surhud; Okura, Yuki; Owen, Russell; Swinbank, John D.; Strauss, Michael A.; Yamada, Yoshihiko; Yamanoi, Hitomi


    In this paper, we describe the optical imaging data processing pipeline developed for the Subaru Telescope's Hyper Suprime-Cam (HSC) instrument. The HSC Pipeline builds on the prototype pipeline being developed by the Large Synoptic Survey Telescope's Data Management system, adding customizations for HSC, large-scale processing capabilities, and novel algorithms that have since been reincorporated into the LSST codebase. While designed primarily to reduce HSC Subaru Strategic Program (SSP) data, it is also the recommended pipeline for reducing general-observer HSC data. The HSC pipeline includes high-level processing steps that generate coadded images and science-ready catalogs as well as low-level detrending and image characterizations.

  1. Failure modes for pipelines in landslide areas

    Energy Technology Data Exchange (ETDEWEB)

    Bruschi, R.; Spinazze, M.; Tomassini, D. [Snamprogetti SpA, Fano (Italy); Cuscuna, S.; Venzi, S. [SNAM SpA, San Donato Milanese (Italy)


    In recent years a number of incidences of pipelines affected by slow soil movements have been reported in the relevant literature. Further related issues such as soil-pipe interaction have been studied both theoretically and through experimental surveys, along with the environmental conditions which are responsible for hazard to the pipeline integrity. A suitable design criteria under these circumstances has been discussed by several authors, in particular in relation to a limit state approach and hence a strain based criteria. The scope of this paper is to describe the failure mechanisms which may affect the pipeline in the presence of slow soil movements impacting on the pipeline, both in the longitudinal and transverse direction. Particular attention is paid to environmental, geometric and structural parameters which steer the process towards one or other failure mechanism. Criteria for deciding upon remedial measures required to guarantee the structural integrity of the pipeline, both in the short and in the long term, are discussed.

  2. optimization for trenchless reconstruction of pipelines

    Directory of Open Access Journals (Sweden)

    Zhmakov Gennadiy Nikolaevich


    Full Text Available Today the technologies of trenchless reconstruction of pipelines are becoming and more widely used in Russia and abroad. One of the most perspective is methods is shock-free destruction of the old pipeline being replaced with the help of hydraulic installations with working mechanism representing a cutting unit with knife disks and a conic expander. A construction of a working mechanism, which allows making trenchless reconstruction of pipelines of different diameters, is optimized and patented and its developmental prototype is manufactured. The dependence of pipeline cutting force from knifes obtusion of the working mechanisms. The cutting force of old steel pipelines with obtuse knife increases proportional to the value of its obtusion. Two stands for endurance tests of the knifes in laboratory environment are offered and patented.

  3. Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Węgrzyn T.


    Full Text Available Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was presented in terms of nitrogen and oxygen amount in WMD (weld metal deposit.


    Directory of Open Access Journals (Sweden)

    BURCA Mircea


    manual welding tests in the light of using the process for welding surfacing being known that in such applications mechanised operations are recommended whenever possible given the latter strengths i.e. increased productivity and quality deposits. The research also aims at achieving a comparative a study between wire mechanised feed based WIG manual welding and the manual rod entry based manual welding in terms of geometry deposits, deposits aesthetics, operating technique, productivity, etc . In this regard deposits were made by means of two welding procedures, and subsequently welding surfacing was made with the optimum values of the welding parameters in this case.

  5. Pipeline integrity: ILI baseline data for QRA

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Todd R. [Tuboscope Pipeline Services, Houston, TX (United States)]. E-mail:; Silva, Jose Augusto Pereira da [Pipeway Engenharia, Rio de Janeiro, RJ (Brazil)]. E-mail:; Marr, James [MARR and Associates, Calgary, AB (Canada)]. E-mail:


    The initial phase of a pipeline integrity management program (IMP) is conducting a baseline assessment of the pipeline system and segments as part of Quantitative Risk Assessment (QRA). This gives the operator's integrity team the opportunity to identify critical areas and deficiencies in the protection, maintenance, and mitigation strategies. As a part of data gathering and integration of a wide variety of sources, in-line inspection (ILI) data is a key element. In order to move forward in the integrity program development and execution, the baseline geometry of the pipeline must be determined with accuracy and confidence. From this, all subsequent analysis and conclusions will be derived. Tuboscope Pipeline Services (TPS), in conjunction with Pipeway Engenharia of Brazil, operate ILI inertial navigation system (INS) and Caliper geometry tools, to address this integrity requirement. This INS and Caliper ILI tool data provides pipeline trajectory at centimeter level resolution and sub-metre 3D position accuracy along with internal geometry - ovality, dents, misalignment, and wrinkle/buckle characterization. Global strain can be derived from precise INS curvature measurements and departure from the initial pipeline state. Accurate pipeline elevation profile data is essential in the identification of sag/over bend sections for fluid dynamic and hydrostatic calculations. This data, along with pipeline construction, operations, direct assessment and maintenance data is integrated in LinaViewPRO{sup TM}, a pipeline data management system for decision support functions, and subsequent QRA operations. This technology provides the baseline for an informed, accurate and confident integrity management program. This paper/presentation will detail these aspects of an effective IMP, and experience will be presented, showing the benefits for liquid and gas pipeline systems. (author)

  6. Effects of welding parameters on the mechanical properties of inert gas welded 6063 Aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ertan, Taner [MAKO Corporation (Turkey); Uguz, Agah [Uludag Univ. (Turkey). Mechnical Engineering Dept.; Ertan, Rukiye


    The influence of welding parameters, namely welding current and gas flow rate, on the mechanical properties of Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW) welded 6063 Aluminum alloy (AA 6063) has been investigated. In order to study the effect of the welding current and gas flow rate, microstructural examination, hardness measurements and room temperature tensile tests have been carried out. The experimental results show that the mechanical properties of GTAW welded joints have better mechanical properties than those of SMAW welded joints. Increasing the welding current appeared to have a beneficial effect on the mechanical properties. However, either increasing or decreasing the gas flow rate resulted in a decrease of hardness and tensile strength. It was also found that, the highest strength was obtained in GTAW welded samples at 220 A and 15 l/min gas flow rate.

  7. Automatic monitoring of vibration welding equipment (United States)

    Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W


    A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

  8. Experimental and simulated strength of spot welds

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Bennedbæk, Rune A.K.; Larsen, Morten B.


    Weld strength testing of single spots in DP600 steel is presented for the three typical testing procedures, i.e. tensile-shear, cross-tension and peel testing. Spot welds are performed at two sets of welding parameters and strength testing under these conditions is presented by load......-elongation curves revealing the maximum load and the elongation at break. Welding and strength testing is simulated by SORPAS® 3D, which allows the two processes to be prepared in a combined simulation, such that the simulated welding properties are naturally applied to the simulation of strength testing. Besides...... the size and shape of the weld nugget, these properties include the new strength of the material in the weld and the heat affected zone based on the predicted hardness resulting from microstructural phase changes simulated during cooling of the weld before strength testing. Comparisons between overall...

  9. Thermal treatment of dissimilar steels' welded joints (United States)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.


    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  10. Closed circuit television welding alignment system

    Energy Technology Data Exchange (ETDEWEB)

    Darner, G.S.


    Closed circuit television (CCTV) weld targeting systems were developed to provide accurate and repeatable positioning of the electrode of an electronic arc welder with respect to the parts being joined. A sliding mirror electrode holder was developed for use with closed circuit television equipment on existing weld fixturing. A complete motorized CCTV weld alignment system was developed to provide weld targeting for even the most critical positioning requirements.

  11. Preventing Contamination In Electron-Beam Welds (United States)

    Goodin, Wesley D.; Gulbrandsen, Kevin A.; Oleksiak, Carl


    Simple expedient eliminates time-consuming, expensive manual hand grinding. Use of groove and backup tube greatly reduces postweld cleanup in some electron-beam welding operations. Tube-backup method developed for titanium parts, configurations of which prevents use of solid-block backup. In new welding configuration, tube inserted in groove to prevent contact between alumina beads and molten weld root. When welding complete and beads and tube removed, only minor spatter remains and is ground away easily.

  12. Pipeline Decommissioning Trial AWE Berkshire UK - 13619

    Energy Technology Data Exchange (ETDEWEB)

    Agnew, Kieran [AWE, Aldermaston, Reading, RG7 4PR (United Kingdom)


    This Paper details the implementation of a 'Decommissioning Trial' to assess the feasibility of decommissioning the redundant pipeline operated by AWE located in Berkshire UK. The paper also presents the tool box of decommissioning techniques that were developed during the decommissioning trial. Constructed in the 1950's and operated until 2005, AWE used a pipeline for the authorised discharge of treated effluent. Now redundant, the pipeline is under a care and surveillance regime awaiting decommissioning. The pipeline is some 18.5 km in length and extends from AWE site to the River Thames. Along its route the pipeline passes along and under several major roads, railway lines and rivers as well as travelling through woodland, agricultural land and residential areas. Currently under care and surveillance AWE is considering a number of options for decommissioning the pipeline. One option is to remove the pipeline. In order to assist option evaluation and assess the feasibility of removing the pipeline a decommissioning trial was undertaken and sections of the pipeline were removed within the AWE site. The objectives of the decommissioning trial were to: - Demonstrate to stakeholders that the pipeline can be removed safely, securely and cleanly - Develop a 'tool box' of methods that could be deployed to remove the pipeline - Replicate the conditions and environments encountered along the route of the pipeline The onsite trial was also designed to replicate the physical prevailing conditions and constraints encountered along the remainder of its route i.e. working along a narrow corridor, working in close proximity to roads, working in proximity to above ground and underground services (e.g. Gas, Water, Electricity). By undertaking the decommissioning trial AWE have successfully demonstrated the pipeline can be decommissioned in a safe, secure and clean manor and have developed a tool box of decommissioning techniques. The tool box of includes

  13. The Very Large Array Data Processing Pipeline (United States)

    Kent, Brian R.; Masters, Joseph S.; Chandler, Claire J.; Davis, Lindsey E.; Kern, Jeffrey S.; Ott, Juergen; Schinzel, Frank K.; Medlin, Drew; Muders, Dirk; Williams, Stewart; Geers, Vincent C.; Momjian, Emmanuel; Butler, Bryan J.; Nakazato, Takeshi; Sugimoto, Kanako


    We present the VLA Pipeline, software that is part of the larger pipeline processing framework used for the Karl G. Jansky Very Large Array (VLA), and Atacama Large Millimeter/sub-millimeter Array (ALMA) for both interferometric and single dish observations.Through a collection of base code jointly used by the VLA and ALMA, the pipeline builds a hierarchy of classes to execute individual atomic pipeline tasks within the Common Astronomy Software Applications (CASA) package. Each pipeline task contains heuristics designed by the team to actively decide the best processing path and execution parameters for calibration and imaging. The pipeline code is developed and written in Python and uses a "context" structure for tracking the heuristic decisions and processing results. The pipeline "weblog" acts as the user interface in verifying the quality assurance of each calibration and imaging stage. The majority of VLA scheduling blocks above 1 GHz are now processed with the standard continuum recipe of the pipeline and offer a calibrated measurement set as a basic data product to observatory users. In addition, the pipeline is used for processing data from the VLA Sky Survey (VLASS), a seven year community-driven endeavor started in September 2017 to survey the entire sky down to a declination of -40 degrees at S-band (2-4 GHz). This 5500 hour next-generation large radio survey will explore the time and spectral domains, relying on pipeline processing to generate calibrated measurement sets, polarimetry, and imaging data products that are available to the astronomical community with no proprietary period. Here we present an overview of the pipeline design philosophy, heuristics, and calibration and imaging results produced by the pipeline. Future development will include the testing of spectral line recipes, low signal-to-noise heuristics, and serving as a testing platform for science ready data products.The pipeline is developed as part of the CASA software package by an

  14. Performance of mesh seam welds in tailor welded blanks; Terado blank yo mash seam yosetsubu no tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Uchihara, M.; Takahashi, M.; Kurita, M.; Hirose, Y.; Fukui, K. [Sumitomo Metal Industries, Ltd., Osaka (Japan)


    Formability, fatigue properties and corrosion behavior of mash seam welded steel sheets were investigated and the results were compared with laser weld. The stretch formability of mash seam weld and laser weld were same level. Mash seam weld however, showed slightly smaller formability in hole expansion test. The fatigue strength of mash seam welds was lower than that of laser welds in case of differential thickness joints. Corrosion was apt to initiate at weld in both mash seam and laser weld with E-coat. The corrosion resistance of welds was improved by using zinc coated steel. 3 refs., 14 figs., 2 tabs.

  15. Welding technology for rails. Rail no setsugo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, M.; Karimine, K. (Nippon Steel Corp., Tokyo (Japan)); Uchino, K.; Sugino, K. (Nippon Steel Corp., Kitakyushu, Fukuoka (Japan). Technical Research Inst. of Yawata Works); Ueyama, K. (JR Railway Technical Research Inst., Tokyo (Japan))


    The rail joining technology is indispensable for making long welded rails. Flush butt welding, gas welding, enclosed arc welding, and thermit welding are used properly as the welding methods. A method for improving the joint reliability by controlling the residual stress distribution of welded joint is investigated to prepare high carbon component weld metal similar to the rail. Problems with each of the welding methods and the newly developed technology to solve the problems are outlined. Composition of the coating is improved also, and a high C system welding rod is developed which has satisfactory weldability. High performance and high efficient new enclosed arc welding technology not available by now is developed which utilizes high carbon welding metal as a new EA welding work technology, and put to practical use. As a result of this study, useful guides are obtained for the establishment of satisfactory thermit welding technology. 17 refs., 16 figs., 1 tab.

  16. Current pipelines for neglected diseases.

    Directory of Open Access Journals (Sweden)

    Paolo di Procolo


    Full Text Available This paper scrutinises pipelines for Neglected Diseases (NDs, through freely accessible and at-least-weekly updated trials databases. It updates to 2012 data provided by recent publications, and integrates these analyses with information on location of trials coordinators and patients recruitment status. Additionally, it provides (i disease-specific information to better understand the rational of investments in NDs, (ii yearly data, to understand the investment trends. The search identified 650 clinical studies. Leishmaniasis, Arbovirus infection, and Dengue are the top three diseases by number of clinical studies. Disease diffusion risk seems to be the most important driver of the clinical trials target choice, whereas the role played by disease prevalence and unmet need is controversial. Number of trials is stable between 2005 and 2010, with an increase in the last two years. Patient recruitment was completed for most studies (57.6%, and Phases II and III account for 35% and 28% of trials, respectively. The primary purpose of clinical investigations is prevention (49.3%, especially for infectious diseases with mosquitoes and sand flies as the vector, and treatment (43.2%, which is the primary target for parasitic diseases Research centres and public organisations are the most important clinical studies sponsors (58.9%, followed by the pharmaceutical industry (24.1%, foundations and non-governmental organisations (9.3%. Many coordinator centres are located in less affluent countries (43.7%, whereas OECD countries and BRICS account for 34.7% and 17.5% of trials, respectively. Information was partially missing for some parameters. Notwithstanding, and despite its descriptive nature, this research has enhanced the evidence of the literature on pipelines for NDs. Future contributions may further investigate whether trials metrics are consistent with the characteristics of the interested countries and the explicative variables of trials location

  17. Current pipelines for neglected diseases. (United States)

    di Procolo, Paolo; Jommi, Claudio


    This paper scrutinises pipelines for Neglected Diseases (NDs), through freely accessible and at-least-weekly updated trials databases. It updates to 2012 data provided by recent publications, and integrates these analyses with information on location of trials coordinators and patients recruitment status. Additionally, it provides (i) disease-specific information to better understand the rational of investments in NDs, (ii) yearly data, to understand the investment trends. The search identified 650 clinical studies. Leishmaniasis, Arbovirus infection, and Dengue are the top three diseases by number of clinical studies. Disease diffusion risk seems to be the most important driver of the clinical trials target choice, whereas the role played by disease prevalence and unmet need is controversial. Number of trials is stable between 2005 and 2010, with an increase in the last two years. Patient recruitment was completed for most studies (57.6%), and Phases II and III account for 35% and 28% of trials, respectively. The primary purpose of clinical investigations is prevention (49.3%), especially for infectious diseases with mosquitoes and sand flies as the vector, and treatment (43.2%), which is the primary target for parasitic diseases Research centres and public organisations are the most important clinical studies sponsors (58.9%), followed by the pharmaceutical industry (24.1%), foundations and non-governmental organisations (9.3%). Many coordinator centres are located in less affluent countries (43.7%), whereas OECD countries and BRICS account for 34.7% and 17.5% of trials, respectively. Information was partially missing for some parameters. Notwithstanding, and despite its descriptive nature, this research has enhanced the evidence of the literature on pipelines for NDs. Future contributions may further investigate whether trials metrics are consistent with the characteristics of the interested countries and the explicative variables of trials location, target

  18. 49 CFR 179.100-9 - Welding. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.100-9 Section 179.100-9... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-9 Welding. (a) All..., appendix W (IBR, see § 171.7 of this subchapter). Welding procedures, welders and fabricators shall be...

  19. 49 CFR 179.220-10 - Welding. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.220-10 Section 179.220-10... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-10 Welding. (a) All joints... of this subchapter). Welding procedures, welders, and fabricators shall be approved. (b) Radioscopy...

  20. 49 CFR 179.400-11 - Welding. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.400-11 Section 179.400-11...-11 Welding. (a) Except for closure of openings and a maximum of two circumferential closing joints in... subchapter). (d) Each welding procedure, welder, and fabricator must be approved. [Amdt. 179-32, 48 FR 27708...

  1. 49 CFR 179.200-10 - Welding. (United States)


    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.200-10 Section 179.200-10... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-10 Welding. (a) All joints... W (IBR, see § 171.7 of this subchapter). Welding procedures, welders and fabricators shall be...

  2. 30 CFR 77.408 - Welding operations. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding operations. 77.408 Section 77.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... for Mechanical Equipment § 77.408 Welding operations. Welding operations shall be shielded and the...

  3. 30 CFR 75.1729 - Welding operations. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding operations. 75.1729 Section 75.1729 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1729 Welding operations. Welding...

  4. Friction welding thermal and metallurgical characteristics

    CERN Document Server

    Yilbas, Bekir Sami


    This book provides insight into the thermal analysis of friction welding incorporating welding parameters such as external, duration, breaking load, and material properties. The morphological and metallurgical changes associated with the resulting weld sites are analysed using characterization methods such as electron scanning microscope, energy dispersive spectroscopy, X-ray Diffraction, and Nuclear reaction analysis.

  5. Welding Using Chilled-Inert-Gas Purging (United States)

    Mcgee, William F.; Rybicki, Daniel J.


    Report describes study of fusion welding using chilled inert gas. Marked improvement shown in welding of aluminum using chilled helium gas. Chilling inert gas produces two additional benefits: 1) creation of ultradense inert atmosphere around welds; 2) chilled gas cools metal more quickly down to temperature at which metals not reactive.

  6. 46 CFR 154.665 - Welding procedures. (United States)


    ... 46 Shipping 5 2010-10-01 2010-10-01 false Welding procedures. 154.665 Section 154.665 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Construction § 154.665 Welding procedures. Welding procedure tests for cargo tanks for a design temperature...

  7. Low Speed Control for Automatic Welding (United States)

    Iceland, W. E.


    Amplifier module allows rotating positioner of automatic welding machine to operate at speeds below normal range. Low speeds are precisely regulated by a servomechanism as are normal-range speeds. Addition of module to standard welding machine makes it unnecessary to purchase new equipment for low-speed welding.

  8. 49 CFR 195.214 - Welding procedures. (United States)


    ... accordance with welding procedures qualified under Section 5 of API 1104 or Section IX of the ASME Boiler and Pressure Vessel Code (incorporated by reference, see § 195.3) . The quality of the test welds used to... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 195.214 Section 195.214...

  9. Welding multiple plies with an electron beam (United States)

    Kiluk, F. J.


    Method for electron-beam welding of multi-ply metal sheets eliminates ply separation and minimizes porosity. Method was developed for assembling bellows made of four plies of iron/nickel alloy sheets. Method consists of making successive stitch welds with electron beam until weld seam is completely filled in and all plies have been penetrated.

  10. Viewing electron-beam welds in progress (United States)

    Armenoff, C. T.


    With aid of optical filter, operator of electron-beam welding machine can view TV image of joint that is being welded and can make corrections as necessary. Operator can see when weld bead gets out of alinement, for example, and compensate for deflection of electron beam caused by changes in magnetic field.

  11. [Dental welding titanium and its clinical usage]. (United States)

    Li, H; Xiao, M; Zhao, Y


    Due to its excellent biocompatibility, desirable chemical and mechanical properties, Titanium has been used for implant denture, RPD and FPD, where welding techniques were indispensable. This paper introduces 5 useful modern ways to weld Titanium and their clinical usage. They are: laser, plasma welding, TIG, infraned brazing and Hruska electrowelding.

  12. Technology of welding aluminum alloys-III (United States)

    Harrison, J. R.; Kor, L. J.; Oleksiak, C. E.


    Control of porosity in weld beads was major objective in development of aluminum welding program. Porosity, most difficult defect to control, is caused by hydrogen gas unable to escape during solidification. Hard tooling allows hotter bead than free-fall tooling so hydrogen bubbles can boil out instead of forming pores. Welding position, moisture, and cleanliness are other important factors in control of porosity.

  13. Laser weld process monitoring and control using chromatic filtering of thermal radiation from a weld pool

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung; Kim, Min Suk; Baik, Sung Hoon; Chung, Chin Man


    The application of high power Nd: YAG lasers for precision welding in industry has been growing quite fast these days in diverse areas such as the automobile, the electronics and the aerospace industries. These diverse applications also require the new developments for the precise control and the reliable process monitoring. Due to the hostile environment in laser welding, a remote monitoring is required. The present development relates in general to weld process monitoring techniques, and more particularly to improved methods and apparatus for real-time monitoring of thermal radiation of a weld pool to monitor a size variation and a focus shift of the weld pool for weld process control, utilizing the chromatic aberration of focusing lens or lenses. The monitoring technique of the size variation and the focus shift of a weld pool is developed by using the chromatic filtering of the thermal radiation from a weld pool. The monitoring of weld pool size variation can also be used to monitor the weld depth in a laser welding. Furthermore, the monitoring of the size variation of a weld pool is independent of the focus shift of a weld pool and the monitoring of the focus shift of a weld pool is independent of the size variation of a weld pool.

  14. Study on visual image information detection of external angle weld based on arc welding robot (United States)

    Liu, Xiaorui; Liu, Nansheng; Sheng, Wei; Hu, Xian; Ai, Xiaopu; Wei, Yiqing


    Nowadays, the chief development trend in modern welding technology is welding automation and welding intelligence. External angle weld has a certain proportion in mechanical manufacture industries. In the real-time welding process, due to hot deformation and the fixture of workpieces used frequently, torch will detach welding orbit causes deviation, which will affect welding quality. Therefore, elimination weld deviation is the key to the weld automatic tracking system. In this paper, the authors use the self-developed structured light vision sensor system which has significant advantage compared with arc sensors to capture real-time weld images. In the project of VC++6.0 real-time weld image processing, after binaryzation with threshold value seventy, 3*1 median filter, thinning, obtain weld main stripe. Then, using the extraction algorithm this paper proposed to obtain weld feature points, and compute position of weld. Experiment result verified that the extraction algorithm can locate feature points rapidly and compute the weld deviation accurately.

  15. Contamination and solid state welds.

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Bernice E.


    Since sensitivity to contamination is one of the verities of solid state joining, there is a need for assessing contamination of the part(s) to be joined, preferably nondestructively while it can be remedied. As the surfaces that are joined in pinch welds are inaccessible and thus provide a greater challenge, most of the discussion is of the search for the origin and effect of contamination on pinch welding and ways to detect and mitigate it. An example of contamination and the investigation and remediation of such a system is presented. Suggestions are made for techniques for nondestructive evaluation of contamination of surfaces for other solid state welds as well as for pinch welds. Surfaces that have good visual access are amenable to inspection by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Although other techniques are useful for specific classes of contaminants (such as hydrocarbons), DRIFT can be used most classes of contaminants. Surfaces such as the interior of open tubes or stems that are to be pinch welded can be inspected using infrared reflection spectroscopy. It must be demonstrated whether or not this tool can detect graphite based contamination, which has been seen in stems. For tubes with one closed end, the technique that should be investigated is emission infrared spectroscopy.

  16. Laser welding of selected aerospace alloys (United States)

    Ebadan, Gracie E.

    The study was aimed at developing an understanding of the microstructural effects of the laser welding process on the alloys, and assessing the structural integrity of the resultant welds. The effect of laser processing parameters such as laser power, laser beam traverse speed, lens focal length, and the manipulation of these parameters on the welding efficiency and weld area integrity was also investigated. Other tasks within the project included a study on the possibility of using an anodic film to enhance the laser weld ability of Al 6061. Finally, attempts were made to identify phases observed in the weld area of the composite materials. Nimonics C263 and PE11 exhibited laser welds free of cracks and porosity. The difference in composition between the two alloys did not result in any significant dissimilarities in their response to the laser welding process. The welds in both alloys exhibited a fine columnar dendritic microstructure, and while carbides were observed in the interdendritic regions of the welds, electron optical analysis did not reveal any gamma' precipitates in this region. It was concluded that for the welding of thin gage materials above a threshold laser power the resultant welding efficiency shows a greater dependence on laser beam mode, and laser spot size, than on laser power, and beam traverse speed. Aluminum 6061 was not easily welded with a laser in its as received form, and the welds showed some degree of porosity. Anodizing was found to improve the welding efficiency in this material. While the presence of an anodic film on the metal surface increased the welding efficiency of the alloy, no relationship was found between the thickness of the anodic film and welding efficiency in the range of film thicknesses investigated. Weld regions were observed to be cellular dendritic in structure, with narrow heat affected zones. No precipitates or low melting point phases could be identified in the weld region. Melt zones were successfully

  17. Analysis and Comparison of Aluminum Alloy Welded Joints Between Metal Inert Gas Welding and Tungsten Inert Gas Welding (United States)

    Zhao, Lei; Guan, Yingchun; Wang, Qiang; Cong, Baoqiang; Qi, Bojin


    Surface contamination usually occurs during welding processing and it affects the welds quality largely. However, the formation of such contaminants has seldom been studied. Effort was made to study the contaminants caused by metal inert gas (MIG) welding and tungsten inert gas (TIG) welding processes of aluminum alloy, respectively. SEM, FTIR and XPS analysis was carried out to investigate the microstructure as well as surface chemistry. These contaminants were found to be mainly consisting of Al2O3, MgO, carbide and chromium complexes. The difference of contaminants between MIG and TIG welds was further examined. In addition, method to minimize these contaminants was proposed.

  18. Electron Beam Welding to Join Gamma Titanium Aluminide Articles (United States)

    Kelly, Thomas Joseph (Inventor)


    A method is provided for welding two gamma titanium aluminide articles together. The method includes preheating the two articles to a welding temperature of from about 1700 F to about 2100 F, thereafter electron beam welding the two articles together at the welding temperature and in a welding vacuum to form a welded structure, and thereafter annealing the welded structure at an annealing temperature of from about 1800 F to about 2200 F, to form a joined structure.

  19. Materials and welding engineering in advanced coal utilization plants

    Energy Technology Data Exchange (ETDEWEB)

    Schuhmacher, D.; Schulze-Frielinghaus, W.; Puetz, J.; Eichhorn, F.; Gaever, E. van


    The authors present the findings of studies on welding methods for high-temperature alloys used in advanced coal gasification plants. They discuss weld preparation, automatic TIG welding, MIG welding (also with pulsed arc) and plasma arc welding. The mechanical properties of welded joints before and after age hardening are investigated, and the results of fatigue and corrosion tests are presented. The welding methods are compared with a view to their suitability for high-temperature materials.

  20. Advanced Welding Tool (United States)


    Accutron Tool & Instrument Co.'s welder was originally developed as a tool specifically for joining parts made of plastic or composite materials in any atmosphere to include the airless environment of space. Developers decided on induction or magnetic heating to avoid causing deformation and it also can be used with almost any type of thermoplastic material. Induction coil transfers magnetic flux through the plastic to a metal screen that is sandwiched between the sheets of plastic to be joined. When welder is energized, alternating current produces inductive heating on the screen causing the adjacent plastic surfaces to melt and flow into the mesh, creating a bond on the total surface area. Dave Brown, owner of Great Falls Canoe and Kayak Repair, Vienna, VA, uses a special repair technique based on operation of the Induction Toroid Welder to fix canoes. Whitewater canoeing poses the problem of frequent gashes that are difficult to repair. The main reason is that many canoes are made of plastics. The commercial Induction model is a self-contained, portable welding gun with a switch on the handle to regulate the temperature of the plastic melting screen. Welder has a broad range of applications in the automobile, appliance, aerospace and construction industries.

  1. Effect of weld spacing on microstructure and mechanical properties of CLAM electron beam welding joints

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yutao; Huang, Bo, E-mail:; Zhang, Junyu; Zhang, Baoren; Liu, Shaojun; Huang, Qunying


    Highlights: • The welded joints of CLAM steel with different weld spacings have been fabricated with electron beam welding, and a simplified model of CLAM sheet was proposed. • The microstructure and mechanical properties such as microhardness, impact and tensile were investigated at different welding spacing for both conditions of as-welded and post weld heat treatment (PWHT). • The effect of the welding thermal cycle was significantly when the weld spacings were smaller than 4 mm. • When the weld spacing was small enough, the original microstructures would be fragmented with the high heat input. - Abstract: China low activation martensitic (CLAM) steel has been chosen as the primary structural material in the designs of dual function lithium-lead (DFLL) blanket for fusion reactors, China helium cooled ceramic breeder (HCCB) test blanket module (TBM) for ITER and China fusion engineering test reactor (CFETR) blanket. The cooling components of the blankets are designed with high density cooling channels (HDCCs) to remove the high nuclear thermal effectively. Hence, the welding spacing among the channels are small. In this paper, the welded joints of CLAM steel with different weld spacings have been fabricated with electron beam welding (EBW). The weld spacing was designed to be 2 mm, 3 mm, 4 mm, 6 mm and 8 mm. The microstructure and mechanical properties such as microhardness, impact and tensile were investigated at different welding spacing for both conditions of as-welded and post weld heat treatment (PWHT). The PWHT is tempering at 740 °C for 120 min. The results showed that the grain size in the heat affected zone (HAZ) increased with the increasing weld spacing, and the joint with small weld spacing had a better performance after PWHT. This work would give useful guidance to improve the preparation of the cooling components of blanket.

  2. ARTIP: Automated Radio Telescope Image Processing Pipeline (United States)

    Sharma, Ravi; Gyanchandani, Dolly; Kulkarni, Sarang; Gupta, Neeraj; Pathak, Vineet; Pande, Arti; Joshi, Unmesh


    The Automated Radio Telescope Image Processing Pipeline (ARTIP) automates the entire process of flagging, calibrating, and imaging for radio-interferometric data. ARTIP starts with raw data, i.e. a measurement set and goes through multiple stages, such as flux calibration, bandpass calibration, phase calibration, and imaging to generate continuum and spectral line images. Each stage can also be run independently. The pipeline provides continuous feedback to the user through various messages, charts and logs. It is written using standard python libraries and the CASA package. The pipeline can deal with datasets with multiple spectral windows and also multiple target sources which may have arbitrary combinations of flux/bandpass/phase calibrators.

  3. Optimal hub location in pipeline networks

    Energy Technology Data Exchange (ETDEWEB)

    Dott, D.R.; Wirasinghe, S.C.; Chakma, A. [Univ. of Calgary, Alberta (Canada)


    This paper discusses optimization strategies and techniques for the location of natural gas marketing hubs in the North American gas pipeline network. A hub is a facility at which inbound and outbound network links meet and freight is redirected towards their destinations. Common examples of hubs used in the gas pipeline industry include gas plants, interconnects and market centers. Characteristics of the gas pipeline industry which are relevant to the optimization of transportation costs using hubs are presented. Allocation techniques for solving location-allocation problems are discussed. An outline of the research in process by the authors in the field of optimal gas hub location concludes the paper.

  4. Study of Mechanical Properties and Characterization of Pipe Steel welded by Hybrid (Friction Stir Weld + Root Arc Weld) Approach

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Wasson, Andrew J [ExxonMobil, Upstream Research Company (URC); Fairchild, Doug P [ExxonMobil, Upstream Research Company (URC); Wang, Yanli [ORNL; Feng, Zhili [ORNL


    Friction stir welding (FSW) has recently attracted attention as an alternative construction process for gas/oil transportation applications due to advantages compared to fusion welding techniques. A significant advantage is the ability of FSW to weld the entire or nearly the entire wall thickness in a single pass, while fusion welding requires multiple passes. However, when FSW is applied to a pipe or tube geometry, an internal back support anvil is required to resist the plunging forces exerted during FSW. Unfortunately, it may not be convenient or economical to use internal backing support due to limited access for some applications. To overcome this issue, ExxonMobil recently developed a new concept, combining root arc welding and FSW. That is, a root arc weld is made prior to FSW that supports the normal loads associated with FSW. In the present work, mechanical properties of a FSW + root arc welded pipe steel are reported including microstructure and microhardness.

  5. Metal vaporization from weld pools (United States)

    Block-Bolten, A.; Eagar, T. W.


    Experimental studies of alloy vaporization from aluminum and stainless steel weld pools have been made in order to test a vaporization model based on thermodynamic data and the kinetic theory of gases. It is shown that the model can correctly predict the dominant metal vapors that form but that the absolute rate of vaporization is not known due to insufficient knowledge of the surface temperature distribution and subsequent condensation of the vapor in the cooler regions of the metal. Values of the net evaporation rates for different alloys have been measured and are found to vary by two orders of magnitude. Estimated maximum weld pool temperatures based upon the model are in good agreement with previous experimental measurements of electron beam welds.



    Dhananjay Kumar*, Dharamvir mangal


    The effect of welding process on the distortion with 304L stainless steel 12thk weld joints made by TIG (tungsten inert gas) and SMAW (Shielded metal arc welding) welding process involving different type joint configuration have been studied. The joint configurations employed were double V-groove edge preparation for double side SMAW welding and square – butt preparation for double side TIG welding. All weld joints passed by radiographic. Distortion measurements were carried out using height ...

  7. Laser Beam Submerged Arc Hybrid Welding (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan; Schleser, Markus; Mokrov, Oleg; Rossiter, Eduardo

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.

  8. Peculiarities and future development of space welding (United States)

    Shulym, V. F.; Lapchinskii, V. F.; Nikitskii, V. P.; Demidov, D. L.; Neznamova, L. O.

    The paper deals with the peculiar features of space as a medium in which welding operations are performed. Studies of different methods of welding carried out both in the plane-laboratory and in space are briefly described, and the comparative characteristics of the most promising methods of welding for space conditions are given. The selection of electron beam as a basic method for space is supported. The paper considers the main welding processes performed in space with the help of an electron beam, such as heating, brazing, welding, cutting and coating.

  9. Grain refinement control in TIG arc welding (United States)

    Iceland, W. F.; Whiffen, E. L. (Inventor)


    A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed. In the method the frequency of dc welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored. At some frequency in the preselected range the arc gas voltage will pass through a maximum. By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced.

  10. Advantages of new micro-jet welding technology on weld microstructure control

    Directory of Open Access Journals (Sweden)

    Jan PIWNIK


    Full Text Available An innovative apparatus to welding process with micro-jet cooling of the weld made it possible to carry out technological tests, which have proved theoretical considerations about this problem. This project gives real opportunities for professional development in the field of welding with controlling the parameters of weld structure. These tests have proved that the new micro-jet technology has the potential for growth. It may be great achievement of welding technology in order to increase weld metal strength. The new technology with micro-jet cooling may have many practical applications in many fields, for example such as in the transport industry or to repair damaged metal elements. The advantages of the new device over the traditional system are the ability to control the structure of the weld, the weld mechanical performance increases and improve the quality of welded joints.

  11. Experimental Study of the Redistribution of Welding Distortion According to the Partial Removal of Welded Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Rae; Wang, Chao; Kim, Jae Woong [Yeungnam University, Kyungsan (Korea, Republic of)


    During the welding process, welding distortion is caused by the non-uniformity of the temperature distribution in the weldment. Welding distortion is redistributed because the residual stress and rigidity change according to the removal of the welded structure. In shipbuilding in particular, this phenomenon may be observed during the cutting process of lugs that are attached to blocks for transfer. The redistribution of welding distortion also causes problems, such as damage to the cutting tool. The aim of this study is to experimentally analyze the redistribution of welding distortion because of the partial removal of the welded structure. In the experiments conducted in this study, fillet welding and cutting were performed, and longitudinal bending and angular distortion in the welded structures were then investigated and analyzed.

  12. 49 CFR 192.513 - Test requirements for plastic pipelines. (United States)


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Test requirements for plastic pipelines. 192.513 Section 192.513 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND... Test requirements for plastic pipelines. (a) Each segment of a plastic pipeline must be tested in...

  13. 49 CFR 195.57 - Filing offshore pipeline condition reports. (United States)


    ... TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.57... inspected. (5) Length and date of installation of each exposed pipeline segment, and location; including, if... tract. (6) Length and date of installation of each pipeline segment, if different from a pipeline...


    Directory of Open Access Journals (Sweden)

    Nachimani Charde


    Full Text Available The resistance spot welding process is accomplished by forcing huge amounts of current flow from the upper electrode tip through the base metals to the lower electrode tip, or vice versa or in both directions. A weld joint is established between the metal sheets through fusion, resulting in a strong bond between the sheets without occupying additional space. The growth of the weld nugget (bond between sheets is therefore determined from the welding current density; sufficient time for current delivery; reasonable electrode pressing force; and the area provided for current delivery (electrode tip. The welding current and weld time control the root penetration, while the electrode pressing force and electrode tips successfully accomplish the connection during the welding process. Although the welding current and weld time cause the heat generation at the areas concerned (electrode tip area, the electrode tips’ diameter and electrode pressing forces also directly influence the welding process. In this research truncated-electrode deformation and mushrooming effects are observed, which result in the welded areas being inconsistent due to the expulsion. The copper to chromium ratio is varied from the tip to the end of the electrode whilst the welding process is repeated. The welding heat affects the electrode and the electrode itself influences the shape of the weld geometry.

  15. Experimental investigation on the weld pool formation process in plasma keyhole arc welding (United States)

    Van Anh, Nguyen; Tashiro, Shinichi; Van Hanh, Bui; Tanaka, Manabu


    This paper seeks to clarify the weld pool formation process in plasma keyhole arc welding (PKAW). We adopted, for the first time, the measurement of the 3D convection inside the weld pool in PKAW by stereo synchronous imaging of tungsten tracer particles using two sets of x-ray transmission systems. The 2D convection on the weld pool surface was also measured using zirconia tracer particles. Through these measurements, the convection in a wide range of weld pools from the vicinity of the keyhole to the rear region was successfully visualized. In order to discuss the heat transport process in a weld pool, the 2D temperature distribution on the weld pool surface was also measured by two-color pyrometry. The results of the comprehensive experimental measurement indicate that the shear force due to plasma flow is found to be the dominant driving force in the weld pool formation process in PKAW. Thus, heat transport in a weld pool is considered to be governed by two large convective patterns near the keyhole: (1) eddy pairs on the surface (perpendicular to the torch axis), and (2) eddy pairs on the bulk of the weld pool (on the plane of the torch). They are formed with an equal velocity of approximately 0.35 m s‑1 and are mainly driven by shear force. Furthermore, the flow velocity of the weld pool convection becomes considerably higher than that of other welding processes, such as TIG welding and GMA welding, due to larger plasma flow velocity.

  16. Residual stress characterization of welds and post-weld processes using x-ray diffraction techniques (United States)

    Brauss, Michael E.; Pineault, James A.; Eckersley, John S.


    This paper illustrates the importance of residual stress characterization in welds and post weld processes. The failure to characterize residual stresses created during welding and/or post weld processes can lead to unexpected occurrences of stress corrosion cracking, distortion, fatigue cracking as well as instances of over design or over processing. The development of automated residual stress mapping and the availability of portable and fast equipment have now made the characterization of residual stresses using x-ray diffraction practical for process control and optimization. The paper presents examples where x-ray diffraction residual stress characterization techniques were applied on various kinds of welds including arc welds, TIG welds, resistance welds, laser welds and electron beam welds. The nondestructive nature of the x-ray diffraction technique has made the residual stress characterization of welds a useful tool for process optimization and failure analysis, particularly since components can be measured before and after welding and post welding processes. Some examples presented show the residual stresses before and after the application of post weld processes such as shot peening, grinding and heat treatment.

  17. Weld-brazing of titanium (United States)

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.


    A joining process, designated weld-brazing, which combines resistance spotwelding and brazing has been developed at the NASA Langley Research Center. Resistance spot-welding is employed to position and align the parts and to establish a suitable faying surface gap for brazing; it contributes to the integrity of the joint. Brazing enhances the properties of the joint and reduces the stress concentrations normally associated with spotwelds. Ti-6Al-4V titanium alloy joints have been fabricated using 3003 aluminum braze both in a vacuum furnace and in a retort containing an inert gas environment.

  18. Shimmed electron beam welding process (United States)

    Feng, Ganjiang; Nowak, Daniel Anthony; Murphy, John Thomas


    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  19. Laser welding of micro plastic parts (United States)

    Haberstroh, E.; Hoffmann, W.-M.


    Most welding processes for plastics do not meet the demands of micro technology and thus cannot be applied in this innovative industrial sector. One of the few techniques which are applicable in this sector is the laser transmission welding, which has distinctive advantages like low mechanical and thermal load of the joining parts. This makes the laser particularly suitable for the welding of micro plastics parts. Thereby, contour welding is a process variant of laser transmission welding enabling the welding of complex and even three-dimensional weld contours. But so far it has not yet been applied for welding plastics parts of micro scale in the industrial practice. Recent research at the Institute of Plastics Processing (IKV) at the RWTH Aachen University shows the feasibility of this process to weld small and complex micro parts. Good mechanical properties can be achieved. However, it is necessary to apply measures to reduce the formation of flash. Moreover, it can be shown that there is a strong influence of some material parameters on the laser welding process so that some plastics are more suitable than others for the contour welding in micro technology.

  20. TIG welding power supply with improved efficiency

    Directory of Open Access Journals (Sweden)

    Сергій Володимирович Гулаков


    Full Text Available In the article, the influence of the DC component of the welding current during TIG (Tungsten Inert Gas welding is discussed. Known methods of DC current cancellation are reviewed, such as capacitor bank or diode/thyristor network insertion in the secondary circuit of the welding transformer. A new method of controlling the magnitude and shape of the TIG welding current is proposed. The idea is to insert a controlled voltage source in the secondary circuit of the welding transformer. This controlled voltage source is realized using a full-bridge voltage source inverter (VSI. VSI control system design issues are discussed. VSI is controlled by a three-level hysteretic current controller, while current reference is generated using lookup table driven by PLL (Phase Locked Loop locked to the mains frequency. Simulation results are shown. The proposed topology of TIG power supply allows to provide magnitude and shape control of the welding current, with the limitation that its DC component must be zero. Thus, some capabilities of professional AC-TIG welders are obtained using substantially lower cost components: VSI built using high-current low voltage MOSFETs with control system based on 32-bit ARM microcontroller. The use of proposed TIG welding power supply will eliminate the DC component of the welding current, improve welding transformer’s power factor and improve welding technology by increasing the welding arc stability

  1. Experimental analysis of cut welding in aluminium

    DEFF Research Database (Denmark)

    Dorph, Pernille; De Chiffre, Leonardo; Bay, Niels


    Cut welding is a newly developed cold pressure welding process. In the present work, an experimental investigation was carried out analyzing the mechanisms involved in cut welding of a block to a strip. Experiments were carried out in technically pure aluminium. The investigation has involved...... tensile testing and metallographic investigations of the welds. The results show that this variant of cut welding is a very reproducible process giving a weld strength equal to 30-40% the strength of the parent material. The experiments have shown that the reason for this relatively low strength...... is an uneven pressure distribution along the weld due to a wave formed during sliding. Attempts to alter the material flow during sliding are presented....

  2. Welding of gamma titanium aluminide alloys (United States)

    Smashey, Russell W. (Inventor); Kelly, Thomas J. (Inventor); Snyder, John H. (Inventor); Sheranko, Ronald L. (Inventor)


    An article made of a gamma titanium aluminide alloy is welded, as for example in the weld repair of surface cracks, by removing foreign matter from the area to be welded, first stress relieving the article, cooling the entire article to a welding temperature of from about F. to about F., welding a preselected region in an inert atmosphere at the welding temperature, and second stress relieving the article. Welding is preferably accomplished by striking an arc in the preselected region so as to locally melt the alloy in the preselected region, providing a filler metal having the same composition as the gamma titanium aluminide alloy of the article, and feeding the filler metal into the arc so that the filler metal is melted and fused with the article to form a weldment upon solidification.

  3. Numerical Simulation of Duplex Steel Multipass Welding

    Directory of Open Access Journals (Sweden)

    Giętka T.


    Full Text Available Analyses based on FEM calculations have significantly changed the possibilities of determining welding strains and stresses at early stages of product design and welding technology development. Such an approach to design enables obtaining significant savings in production preparation and post-weld deformation corrections and is also important for utility properties of welded joints obtained. As a result, it is possible to make changes to a simulated process before introducing them into real production as well as to test various variants of a given solution. Numerical simulations require the combination of problems of thermal, mechanical and metallurgical analysis. The study presented involved the SYSWELD software-based analysis of GMA welded multipass butt joints made of duplex steel sheets. The analysis of the distribution of stresses and displacements were carried out for typical welding procedure as during real welding tests.

  4. Residual stress simulation of circumferential welded joints

    Directory of Open Access Journals (Sweden)

    Melicher R.


    Full Text Available Residual stresses are an important consideration in the component integrity and life assessment of welded structure. The welding process is very complex time dependent physical phenomenon with material nonlinearity. The welding is a thermal process with convection between fluid flow and welding body, between welding bodyand environment. Next type of boundary conditions is radiation and thermo-mechanical contact on the outer surface of gas pipe in the near of weld. The temperature variation so obtained is utilised to find the distribution of the stress field.In this paper, a brief review of weld simulation and residual stress modelling using the finite element method (FEM by commercial software ANSYS is presented. Thermo-elastic-plastic formulations using a von Mises yield criterion with nonlinear kinematics hardening has been employed. Residual axial and hoop stresses obtained from the analysis have been shown. The commercial FEM code ANSYS was used for coupled thermalmechanical analysis.

  5. Yield load solutions of heterogeneous welded joints

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, D., E-mail: dkozak@sfsb.h [Mechanical Engineering Faculty in Slavonski Brod, Josip Juraj Strossmayer University of Osijek, Trg Ivane Brlic-Mazuranic 2, Hr-35000 Slavonski Brod (Croatia); Gubeljak, N. [Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor (Slovenia); Konjatic, P.; Sertic, J. [Mechanical Engineering Faculty in Slavonski Brod, Josip Juraj Strossmayer University of Osijek, Trg Ivane Brlic-Mazuranic 2, Hr-35000 Slavonski Brod (Croatia)


    The aim of this paper is to establish yield load solutions when the materials inhomogeneity within the weld is present, which is usually the case in repair welding. The effect of yield strength mismatch of welded joints performed with different geometry on the yield load value has been investigated in the context of single edge notched fracture toughness specimen subjected to bending SE(B) using the finite element method. The crack was located in the center of the weld and the two most important geometrical parameters were identified as: crack length ratio a/W as well as slenderness of the welded joint, which were systematically varied. One practical and four additional combinations of filler materials, with the same portion of overmatched part and undermatched part of the weld, were analyzed, and plane strain FE solutions for the case when the crack is located in the overmatched half of the heterogeneous weld were obtained.

  6. Mechanical Properties of Plug Welds after Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Hadryś D.


    Full Text Available New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF in weld metal deposit (WMD is obtained in MIG welding method with micro-jet cooling in relation to ordinary MIG welding method. This article presents the influence of the cooling medium and the number of micro-jet streams on mechanical properties of the welded joint. Mechanical properties were described by force which is necessary to destroy weld joint.

  7. A Brief Introduction to the Theory of Friction Stir Welding (United States)

    Nunes, Arthur C., Jr.


    Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and is already an important welding process for the aerospace industry, where welds of optimal quality are demanded. The structure of welds determines weld properties. The structure of friction stir welds is determined by the flow field in the weld metal in the vicinity of the weld tool. A simple kinematic model of the FSW flow field developed at Marshall Space Flight Center, which enables the basic features of FSW microstructure to be understood and related to weld process parameters and tool design, is explained.

  8. Mechanical Properties of Plug Welds after Micro-Jet Cooling


    Hadryś D.


    New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF) in weld metal deposit...

  9. Regular pipeline maintenance of gas pipeline using technical operational diagnostics methods

    Energy Technology Data Exchange (ETDEWEB)

    Volentic, J. [Gas Transportation Department, Slovensky plynarensky priemysel, Slovak Gas Industry, Bratislava (Slovakia)


    Slovensky plynarensky priemysel (SPP) has operated 17 487 km of gas pipelines in 1995. The length of the long-line pipelines reached 5 191 km, distribution network was 12 296 km. The international transit system of long-line gas pipelines ranged 1 939 km of pipelines of various dimensions. The described scale of transport and distribution system represents a multibillion investments stored in the ground, which are exposed to the environmental influences and to pipeline operational stresses. In spite of all technical and maintenance arrangements, which have to be performed upon operating gas pipelines, the gradual ageing takes place anyway, expressed in degradation process both in steel tube, as well as in the anti-corrosion coating. Within a certain time horizon, a consistent and regular application of methods and means of in-service technical diagnostics and rehabilitation of existing pipeline systems make it possible to save substantial investment funds, postponing the need in funds for a complex or partial reconstruction or a new construction of a specific gas section. The purpose of this presentation is to report on the implementation of the programme of in-service technical diagnostics of gas pipelines within the framework of regular maintenance of SPP s.p. Bratislava high pressure gas pipelines. (orig.) 6 refs.

  10. Pipelines in Louisiana, Geographic NAD83, USGS (1999) [pipelines_la_usgs_1999 (United States)

    Louisiana Geographic Information Center — This dataset contains vector line map information of various pipelines throughout the State of Louisiana. The vector data contain selected base categories of...

  11. Fuzzy logic for pipelines risk assessment

    Directory of Open Access Journals (Sweden)

    Ali Alidoosti


    Full Text Available Pipelines systems are identified to be the safest way of transporting oil and natural gas. One of the most important aspects in developing pipeline systems is determining the potential risks that implementers may encounter. Therefore, risk analysis can determine critical risk items to allocate the limited resources and time. Risk Analysis and Management for Critical Asset Protection (RAMCAP is one of the best methodologies for assessing the security risks. However, the most challenging problem in this method is uncertainty. Therefore, fuzzy set theory is used to model the uncertainty. Thus, Fuzzy RAMCAP is introduced in order to risk analysis and management for pipeline systems. Finally, a notional example from pipeline systems is provided to demonstrate an application of the proposed methodology.

  12. GLAST (FERMI) Data-Processing Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Flath, Daniel L.; Johnson, Tony S.; Turri, Massimiliano; Heidenreich, Karen A.; /SLAC


    The Data Processing Pipeline ('Pipeline') has been developed for the Gamma-Ray Large Area Space Telescope (GLAST) which launched June 11, 2008. It generically processes graphs of dependent tasks, maintaining a full record of its state, history and data products. The Pipeline is used to automatically process the data down-linked from the satellite and to deliver science products to the GLAST collaboration and the Science Support Center and has been in continuous use since launch with great success. The pipeline handles up to 2000 concurrent jobs and in reconstructing science data produces approximately 750GB of data products using 1/2 CPU-year of processing time per day.

  13. Citizenship program in near communities of pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Carina R.; Vilas Boas, Ianne P. [TELSAN Engenharia, Belo Horizonte, MG (Brazil); Bourscheid, Pitagoras [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)


    During the construction of a pipeline, the IENE - Engineering Unit of PETROBRAS, responsible for the construction and erection of pipelines and related plants in northeastern Brazil, crossed more than 7 states and 250 counties, had implemented a social responsibility program, in special a citizenship program. This action was the result of community studies located near of the pipelines AID - Direct Influence Area (438 yards right and left of the pipeline) and through the evidence that those locations were poor and have no personal documents and citizen position in society. This paper intents to share the experience of IENE about its citizen program that worked in three big lines: community mobilization; citizenship qualification; and citizenship board. This last one, turns possible to people obtains theirs personal documents and exercise the plenitude of citizenship. (author)

  14. Epoxy Pipelining Composition and Method of Manufacture. (United States)


    ARLINGTON VA 22217-5660 "Accesion For NTIS CRA &I DTIC TAB El Unannounced i- Justification .- ---- ----- By ---- ----- Distribution I Availability Codes... corrosion and erosion. The pipelining 10 composition forms a barrier which prevents the leaching of, for example, metals from 11 pipes. This invention...invention, 13 more particularly, relates to an epoxy resin/curing agent corrosion -resistant network 14 pipelining composition suitable for the in

  15. A review of bioinformatic pipeline frameworks (United States)


    Abstract High-throughput bioinformatic analyses increasingly rely on pipeline frameworks to process sequence and metadata. Modern implementations of these frameworks differ on three key dimensions: using an implicit or explicit syntax, using a configuration, convention or class-based design paradigm and offering a command line or workbench interface. Here I survey and compare the design philosophies of several current pipeline frameworks. I provide practical recommendations based on analysis requirements and the user base. PMID:27013646

  16. Advanced Control Methods for Optimization of Arc Welding

    DEFF Research Database (Denmark)

    Thomsen, J. S.

    Gas Metal Arc Welding (GMAW) is a proces used for joining pieces of metal. Probably, the GMAW process is the most successful and widely used welding method in the industry today. A key issue in welding is the quality of the welds produced. The quality of a weld is influenced by several factors in...

  17. Mathematical Model Of Variable-Polarity Plasma Arc Welding (United States)

    Hung, R. J.


    Mathematical model of variable-polarity plasma arc (VPPA) welding process developed for use in predicting characteristics of welds and thus serves as guide for selection of process parameters. Parameters include welding electric currents in, and durations of, straight and reverse polarities; rates of flow of plasma and shielding gases; and sizes and relative positions of welding electrode, welding orifice, and workpiece.

  18. Analysis of factors affecting fractures of rails welded by alumino-thermic welding




    On Latvian Railway, the use of the thermic welding is widespread using the ELECTRO-THERMIT Company technology. Today it is a basic method for rail joints. Experience of the operation of rails welded by the thermic welding showed that every year occur from 2 to 3 fractures of thermic joints on the main tracks between stations of Latvian Railway.Such emergence of cracks in the weld joint alongside the scores indicates of great residual stresses in the weld joints made by the thermic welding.

  19. Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling


    Węgrzyn T.; Piwnik J.


    Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was pr...

  20. Resistance spot welding of galvanized steel: Part II. Mechanisms of spot weld nugget formation (United States)

    Gedeon, S. A.; Eagar, T. W.


    Dynamic inspection monitoring of the weld current, voltage, resistance, electrode displacement, and force was performed in conjunction with a detailed study of the effects of material variations and weld process parameter modifications on resistance spot welding of coated and uncoated steels. In order to determine the mechanisms of weld nugget formation and growth, scanning electron microscopy photos were taken of the developing nugget. These physical changes were then related to the dynamic inspection curves and the welding current lobe. The effects of material variations and weld process modifications, the results of which were presented in Part I, can be explained through an understanding of these mechanisms.


    Directory of Open Access Journals (Sweden)

    Leonid KROUPNIK


    Full Text Available In underground mining of solid minerals becoming increasingly common development system with stowing hardening mixtures. In this case the natural ore array after it is replaced by an artificial excavation of solidified filling mixture consisting of binder, aggregates and water. Such a mixture is prepared on the surface on special stowing complexes and transported underground at special stowing pipelines. However, it is transported to the horizons of a few kilometers, which requires a sustainable mode of motion of such a mixture in the pipeline. Hardening stowing mixture changes its rheological characteristics over time, which complicates the calculation of the parameters of pipeline transportation. The article suggests a method of determining the initial parameters of such mixtures: the status coefficient, indicator of transportability, coefficient of hydrodynamic resistance to motion of the mixture. These indicators characterize the mixture in terms of the possibility to transport it through pipes. On the basis of these indicators is proposed methodology for calculating the parameters of pipeline transport hardening filling mixtures in drift mode when traffic on the horizontal part of the mixture under pressure column of the mixture in the vertical part of the backfill of the pipeline. This technique allows stable operation is guaranteed to provide pipeline transportation.

  2. The Ruptured Pipeline: Analysis of the Mining Engineering Faculty Pipeline (United States)

    Poulton, M.


    The booming commodities markets of the past seven years have created an enormous demand for economic geologists, mining engineers, and extractive metallurgists. The mining sector has largely been recession proof due to demand drivers coming from developing rather than developed nations. The strong demand for new hires as well as mid-career hires has exposed the weakness of the U.S. university supply pipeline for these career fields. A survey of mining and metallurgical engineering faculty and graduate students was conducted in 2010 at the request of the Society for Mining, Metallurgy, and Exploration. The goals of the surveys were to determine the demographics of the U.S. faculty in mining and metallurgical engineering, the expected faculty turn over by 2010 and the potential supply of graduate students as the future professorate. All Mining Engineering and Metallurgical Engineering degrees in the U.S. are accredited by the Accreditation Board for Engineering and Technology (ABET) and the specific courses required are set by the sponsoring professional society, Society for Mining, Metallurgy, and Exploration. There are 13 universities in the U.S. that offer a degree in Mining Engineering accredited as Mining Engineering and 1 university that grants a Mining Engineering degree accredited under general engineering program requirements. Faculty numbers are approximately 87 tenure track positions with a total undergraduate enrollment of slightly over 1,000 in the 2008-2009 academic year. There are approximately 262 graduate students in mining engineering in the U.S. including 87 Ph.D. students. Mining Engineering department heads have identified 14 positions open in 2010 and 18 positions expected to be open in the next 5 years and an additional 21 positions open by 2020. The current survey predicts a 56% turn over in mining faculty ranks over the next 10 years but a retirement of 100% of senior faculty over 10 years. 63% of graduate students say they are interested in

  3. Mechanics Model of Plug Welding (United States)

    Zuo, Q. K.; Nunes, A. C., Jr.


    An analytical model has been developed for the mechanics of friction plug welding. The model accounts for coupling of plastic deformation (material flow) and thermal response (plastic heating). The model predictions of the torque, energy, and pull force on the plug were compared to the data of a recent experiment, and the agreements between predictions and data are encouraging.

  4. Fundamentals of Welding. Teacher Edition. (United States)

    Fortney, Clarence; And Others

    These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…

  5. Electrode cartridge for pulse welding

    Energy Technology Data Exchange (ETDEWEB)

    Bonnen, John Joseph Francis; Golovashchenko, Sergey Fedorovich; Mamutov, Alexander; Maison, Lloyd Douglas


    A cartridge assembly for a tool includes a cartridge body or casing that contains a conductor. A conductor is connected to a pulse generator or source of stored charge that is discharged to vaporize the conductor and create an electro-hydraulic or electro-magnetic shockwave that is used to impact or pulse weld two parts together.

  6. Mixing weld gases offers advantages (United States)

    May, J. L.; Mendenhall, M. M.


    Argon added to helium during gas tungsten arc cover-pass welding in the horizontal position results in a better controlled wider bead width, increased arc stability, and reduction in heat input. Adequate filler material wetness and penetration pass coverage is possible with only one pass.

  7. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice


    3.6 km of welds were required for the 1 km long CERN Neutrinos to Gran Sasso (CNGS) decay tube, in which particles produced in the collision with a proton and a graphite target will decay into muons and muon neutrinos. Four highly skilled welders performed this delicate task.

  8. Investigate The Effect Of Welding Parameters On Mechanical Properties During The Welding Of Al-6061 Alloy

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad


    Full Text Available Friction welding is a solid state welding technique which is being used in recent times to weld similar as well as dissimilar metals for getting defect free weld. Many combinations like low carbon to stainless steel austenitic to ferrite stainless steel aluminium to copper and titanium to aluminium or steel have been tried out by various solid state welding processes with quite good results. In the present work the 3 level full factorial design has been employed to investigate the effect of welding parameters on tensile strength toughness and heat generation during the welding of Al-6061 alloy. Mathematical relationships between friction welding parameters and mechanical properties like heat generation tensile strength and toughness have also been developed. An attempt has also been made to examine the fracture surfaces of test specimens using SEM. It has been found that welding speed is the most significant parameter thats affect the heat generation tensile strength and toughness. it has been found that tensile strength and toughness during welding increases with increased in welding speed while tensile strength and toughness initially increased as the welding time increases after that it decreased with increase in welding time. The difference in weight of alloying elements can be clearly seen by analyzing spectrum of elements.

  9. Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials (United States)

    Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei


    Dissimilar materials welded joints provide many advantages in power, automotive, chemical, and spacecraft industries. The weld bead integrity which is determined by process parameters plays a significant role in the welding quality during the fiber laser welding (FLW) of dissimilar materials. In this paper, an optimization method by taking the integrity of the weld bead and weld area into consideration is proposed for FLW of dissimilar materials, the low carbon steel and stainless steel. The relationships between the weld bead integrity and process parameters are developed by the genetic algorithm optimized back propagation neural network (GA-BPNN). The particle swarm optimization (PSO) algorithm is taken for optimizing the predicted outputs from GA-BPNN for the objective. Through the optimization process, the desired weld bead with good integrity and minimum weld area are obtained and the corresponding microstructure and microhardness are excellent. The mechanical properties of the optimized joints are greatly improved compared with that of the un-optimized welded joints. Moreover, the effects of significant factors are analyzed based on the statistical approach and the laser power (LP) is identified as the most significant factor on the weld bead integrity and weld area. The results indicate that the proposed method is effective for improving the reliability and stability of welded joints in the practical production.

  10. Intelligent hybrid system of welding parameters for robotic arc-welding task-level offline programming (United States)

    Peng, Pai; Tian, Jiansong; Wu, Lin; Dai, Ming


    Welding process parameters are indispensable to program arc welding robot. To simplify off-line programming (OLP) for robotic arc welding, we develop an arc welding expert system whcih can generate welding process parameters automatically. Its input data came from the feature database of welding part, which is set up by our feature modeling system. The expert system has become an important module of our RAWTOLPS (Robotic Arc Welding Task-level Off-Line System). It combines case-based reasoning with heuristic rule-based reasoning methods to deal with the welding process design. Moreover, artificial neural networks are introduced to the systems for reasoning and machine learning, and several network modules are developed to learn from welding process database, based on back-propagation neural networks. After some groups of actual welding process data were used to train the network models, several network models are established to both design the welding process and to predict the weld bead shape. Besides the ANN-based learning, cased-based learning are used in the expert system. These two methods have respectively their own characteristics, and can meet qualifications of different users. The experimental data show that the system can accomplish re-learning and expanding of welding process knowledge, and satisfy the command of the off-line programming system.

  11. A unified model of coupled arc plasma and weld pool for double electrodes TIG welding (United States)

    Wang, Xinxin; Fan, Ding; Huang, Jiankang; Huang, Yong


    A three-dimensional model containing tungsten electrodes, arc plasma and a weld pool is presented for double electrodes tungsten inert gas welding. The model is validated by available experimental data. The distributions of temperature, velocity and pressure of the coupled arc plasma are investigated. The current density, heat flux and shear stress over the weld pool are highlighted. The weld pool dynamic is described by taking into account buoyance, Lorentz force, surface tension and plasma drag force. The turbulent effect in the weld pool is also considered. It is found that the temperature and velocity distributions of the coupled arc are not rotationally symmetrical. A similar property is also shown by the arc pressure, current density and heat flux at the anode surface. The surface tension gradient is much larger than the plasma drag force and dominates the convective pattern in the weld pool, thus determining the weld penetration. The anodic heat flux and plasma drag force, as well as the surface tension gradient over the weld pool, determine the weld shape and size. In addition, provided the welding current through one electrode increases and that through the other decreases, keeping the total current unchanged, the coupled arc behaviour and weld pool dynamic change significantly, while the weld shape and size show little change. The results demonstrate the necessity of a unified model in the study of the arc plasma and weld pool.

  12. Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems (United States)

    Henon, B. K.


    Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

  13. Friction factor in smooth and rough gas pipelines. An experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Sletfjerding, Elling


    Flow of high pressure natural gas in pipelines has been studied experimentally. Pipeline flow of natural gas is characterized by high Reynolds numbers due to the low viscosity and relatively high density of pressurized gas. Friction factor correlations for high Reynolds number flow in smooth and rough pipes were developed. To study the effect of wall roughness on pipe flow at high Reynolds numbers 8 test pipes with different wall roughness were fabricated. The wall roughness in 6 of the test pipes was varied by adding glass beads in an epoxy coating applied on the pipe wall. One test pipe was treated with a smooth epoxy coating and one was left untreated. The inner diameter of the test pipes was 150 mm. Measurements of the pressure drop in the pipes were made in a closed flow loop at line pressures of 25, 70, 95 and 120 bar. The Reynolds number of the flow was varied in the range 2-30 million. The wall roughness of the test pipes was measured with a stylus instrument. Correlations between the directly measured wall roughness and the friction factor at fully rough flow conditions were presented. To characterize the wall roughness of the test pipes a parameter combining a measure of the roughness height (R{sub q}) and the texture of the wall roughness was used. Due to the high Reynolds number of the flow, minute irregularities of the pipe wall had significant effect on the friction factor in the pipe. The measured wall roughness of the test pipes was in the range 1.4 < R{sub q} <31 (my)m. The flow experiments in test pipes was compared with data from operating pipelines in the North Sea. The offshore pipelines are coated with the same epoxy coating as used in the test pipes. The friction factor in coated offshore gas pipelines showed smooth behavior when the additional pressure drop due to welds were accounted for. The study of coated gas pipelines showed that the friction factor was significantly lower than predicted by standard correlations.

  14. Study on (100-x)(70Li2S-30P2S5)-xLi2ZrO3 glass-ceramic electrolyte for all-solid-state lithium-ion batteries (United States)

    Lu, Penghao; Ding, Fei; Xu, Zhibin; Liu, Jiaquan; Liu, Xingjiang; Xu, Qiang


    A novel glass-ceramic electrolyte of (100-x)(70Li2S-30P2S5)-xLi2ZrO3 (x = 0, 1, 2, 5) is successfully prepared by a vibratory ball-milling method and followed by a heat-treatment process. Composition of the ternary sulfide electrolyte and the heat-treatment process are optimized by physical characterizations and electrochemical measurements. The testing results show that the optimal substitution quantity of Li2ZrO3 into the Li2S-P2S5 electrolyte substrate is 1 mol %. An appropriate heat-treatment temperature of 99(70Li2S-30P2S5)-1Li2ZrO3 glass-ceramic electrolyte is 285 °C. Among the as-prepared ternary electrolyte samples, 99(70Li2S-30P2S5)-1Li2ZrO3 glass-ceramic electrolyte may exhibit the highest conductivity of 2.85 × 10-3 S cm-1 at room temperature, which is much higher than that of the 70Li2S-30P2S5 glass-ceramic electrolyte. Compared to that of the all-solid-state lithium-ion battery of LiCoO2/70Li2S-30P2S5/In-Li, discharge capacities of all-solid-state lithium-ion battery of LiCoO2/99(70Li2S-30P2S5)-1Li2ZrO3/In-Li may increase 41.0% at the 10th charge-discharge cycle and 21.9% at the 50th charge-discharge cycle, respectively. Furthermore, electrochemical impedance spectroscopy (EIS) analyses of all-solid-state lithium-ion batteries reveal that addition of Li2ZrO3 into the Li2S-P2S5 electrolyte substrate may decrease the interfacial resistance between the electrodes and solid electrolyte. The improvement of electrochemical performances of 99(70Li2S-30P2S5)-1Li2ZrO3 glass-ceramic electrolyte is ascribed to both the stable crystal structure and a high lithium-ion diffusion coefficient of Li2ZrO3.

  15. Laser welding of tailored blanks

    Directory of Open Access Journals (Sweden)

    Peças, P.


    Full Text Available Laser welding has an incrising role in the automotive industry, namely on the sub-assemblies manufacturing. Several sheet-shape parts are laser welded, on a dissimilar combination of thicknesses and materials, and are afterwards formed (stamped being transformed in a vehicle body component. In this paper low carbon CO2 laser welding, on the thicknesses of 1,25 and 0,75 mm, formability investigation is described. There will be a description of how the laser welded blanks behave in different forming tests, and the influence of misalignment and undercut on the formibility. The quality is evaluated by measuring the limit strain and limit effective strain for the laser welded sheets and the base material, which will be presented in a forming limit diagram.

    A soldadura laser assume um papel cada vez mais importante na indústria automóvel, principalmente para a fabricação de sub-conjuntos constituídos por varias partes de chapa de diferentes espessuras (e diferentes materiais, que depois de estampados constituem um componente para integrar num veículo. Descreve-se neste artigo o trabalho de investigação de enformabilidade de chapa de ac.o de baixo carbono soldada por laser de CO2, nas espessuras de 1,25 e 0,75 mm. Apresenta-se uma descrição do comportamento das chapas soldadas por laser em diferentes testes de enformação, e a influência dos defeitos das soldaduras (desalinhamento e queda do banho-undercut no comportamento à enformação. A qualidade é avaliada pela medição da extensão limite e da extensão limite efectiva no material base e no material soldado, que serão representadas num diagrama de limite de enformabilidade.

  16. Improving fatigue performance of rail thermite welds

    Directory of Open Access Journals (Sweden)

    Winiar L.


    Full Text Available Rail transport development offers economic and ecological interests. Nevertheless, it requires heavy investments in rolling material and infrastructure. To be competitive, this transportation means must rely on safe and reliable infrastructure, which requires optimization of all implemented techniques and structure. Rail thermite (or aluminothermic welding is widely used within the railway industry for in-track welding during re-rail and defect replacement. The process provides numerous advantages against other welding technology commonly used. Obviously, future demands on train traffic are heavier axle loads, higher train speeds and increased traffic density. Thus, a new enhanced weld should be developed to prevent accidents due to fracture of welds and to lower maintenance costs. In order to improve such assembly process, a detailed metallurgical study coupled to a thermomechanical modelling of the phenomena involved in the thermite welding process is carried out. Obtained data enables us to develop a new improved thermite weld (type A. This joint is made by modifying the routinely specified procedure (type B used in a railway rail by a standard gap alumino-thermic weld. Joints of type A and B are tested and compared. Based on experimental temperature measurements, a finite element analysis is used to calculate the thermal residual stresses induced. In the vicinity of the weld, the residual stress patterns depend on the thermal conditions during welding as it also shown by litterature [1, 2]. In parallel, X-Ray diffraction has been used to map the residual stress field that is generated in welded rail of types A and B. Their effect on fatigue crack growth in rail welds is studied. An experimental study based on fatigue tests of rails welded by conventional and improved processes adjudicates on the new advances and results will be shown.

  17. ITER lip seal welding and cutting developments

    Energy Technology Data Exchange (ETDEWEB)

    Levesy, B.; Cordier, J.J.; Jokinen, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Kujanpää, V.; Karhu, M. [VTT Technical Research Centre of Finland (Finland); Le Barbier, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Määttä, T. [VTT Technical Research Centre of Finland (Finland); Martins, J.P.; Utin, Y. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)


    Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

  18. Overview of interstate hydrogen pipeline systems.

    Energy Technology Data Exchange (ETDEWEB)

    Gillette, J .L.; Kolpa, R. L


    The use of hydrogen in the energy sector of the United States is projected to increase significantly in the future. Current uses are predominantly in the petroleum refining sector, with hydrogen also being used in the manufacture of chemicals and other specialized products. Growth in hydrogen consumption is likely to appear in the refining sector, where greater quantities of hydrogen will be required as the quality of the raw crude decreases, and in the mining and processing of tar sands and other energy resources that are not currently used at a significant level. Furthermore, the use of hydrogen as a transportation fuel has been proposed both by automobile manufacturers and the federal government. Assuming that the use of hydrogen will significantly increase in the future, there would be a corresponding need to transport this material. A variety of production technologies are available for making hydrogen, and there are equally varied raw materials. Potential raw materials include natural gas, coal, nuclear fuel, and renewables such as solar, wind, or wave energy. As these raw materials are not uniformly distributed throughout the United States, it would be necessary to transport either the raw materials or the hydrogen long distances to the appropriate markets. While hydrogen may be transported in a number of possible forms, pipelines currently appear to be the most economical means of moving it in large quantities over great distances. One means of controlling hydrogen pipeline costs is to use common rights-of-way (ROWs) whenever feasible. For that reason, information on hydrogen pipelines is the focus of this document. Many of the features of hydrogen pipelines are similar to those of natural gas pipelines. Furthermore, as hydrogen pipeline networks expand, many of the same construction and operating features of natural gas networks would be replicated. As a result, the description of hydrogen pipelines will be very similar to that of natural gas pipelines

  19. Transformation pipelines for PROJ.4 (United States)

    Knudsen, Thomas; Evers, Kristian


    Convert the geographic coordinates to 3D cartesian geocentric coordinates Apply a Helmert transformation from ED50 to ETRS89 Convert back from cartesian to geographic coordinates Finally project the geographic coordinates to UTM zone 32 planar coordinates. The homology between these steps and a Unix shell style pipeline is evident. With this as its main architectural inspiration, the primary feature of our implementation is a pipeline driver, that takes as its user supplied arguments, a series of elementary operations, which it strings together in order to implement the full transformation needed. Also, we have added a number of elementary geodetic operations, including Helmert transformations, general high order polynomial shifts (2D Horner's scheme) and the abridged Molodensky transformation. In anticipation of upcoming support for full time-varying transformations, we also introduce a 4D spatiotemporal data type, and a programming interface (API) for handling this. With these improvements in place, we assert that PROJ.4 is now well on its way from being a mostly-map-projection library, to becoming an almost-generic-geodetic-transformation library.

  20. Planning for purging and loading of a newly constructed gas pipeline system using a pipeline simulator

    Energy Technology Data Exchange (ETDEWEB)

    Mohitpour, M.; Kazakoff, J.; Jenkins, A.; Montemurro, D. [TransCanada Corp., Calgary, AB (Canada)


    A brief review of purging and loading of a gas pipeline was presented with a summary of current industry practices. If purging is done when pipelines are put into service, it involves the displacement of air or nitrogen by high pressure natural gas into one end of the pipeline section. If purging is done when a pipeline goes out of service, it involves the displacement of natural gas by air or other neutral gases. Current practices give no consideration to minimize the emission of methane gas into the atmosphere. This paper described a simplified purging calculation method and a simulation technique using commercially available software for planning purging and loading operations of gas pipeline systems. The hydraulic-based simulation technique made it possible to minimize the gas to air interface and minimize the emission of methane gas. The simulation also helped to predict the timing of purging and loading of the pipeline. An example was presented of the newly constructed Mayakan Pipeline in Mexico to demonstrate how the process was developed. Simulation results were favourably compared with field data collected during the actual purging and loading of the pipeline. 11 refs., 5 tabs., 8 figs.

  1. 76 FR 18750 - Humble Gas Pipeline Company; Cobra Pipeline Ltd.; Notice of Baseline Filings (United States)


    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Humble Gas Pipeline Company; Cobra Pipeline Ltd.; Notice of Baseline Filings Take notice that on March 28, 2011, the applicants listed above submitted a revised baseline filing of...

  2. Integrated surface management for pipeline construction: The Mid-America Pipeline Company Four Corners Project (United States)

    Maria L. Sonett


    Integrated surface management techniques for pipeline construction through arid and semi-arid rangeland ecosystems are presented in a case history of a 412-mile pipeline construction project in New Mexico. Planning, implementation and monitoring for restoration of surface hydrology, soil stabilization, soil cover, and plant species succession are discussed. Planning...

  3. The Dangers of Pipeline Thinking: How the School-to-Prison Pipeline Metaphor Squeezes out Complexity (United States)

    McGrew, Ken


    In this essay Ken McGrew critically examines the "school-to-prison pipeline" metaphor and associated literature. The origins and influence of the metaphor are compared with the origins and influence of the competing "prison industrial complex" concept. Specific weaknesses in the "pipeline literature" are examined.…

  4. 76 FR 44985 - Pipeline Safety: Potential for Damage to Pipeline Facilities Caused by Flooding (United States)


    ... River in the past few months. While the cause of the accident is still under investigation, ExxonMobil.... Coordinate with other pipeline operators in the flood area and establish emergency response centers to act as... others involved in post-flood restoration activities of the presence of pipelines and the risks posed by...

  5. 78 FR 41991 - Pipeline Safety: Potential for Damage to Pipeline Facilities Caused by Flooding (United States)


    ... forces sufficient to cause a failure. These forces are increased by the accumulation of debris against... other pipeline operators in the flood area and establish emergency response centers to act as a liaison... involved in post-flood restoration activities of the presence of pipelines and the risks posed by reduced...

  6. 75 FR 4134 - Pipeline Safety: Leak Detection on Hazardous Liquid Pipelines (United States)


    ... safety study on pipeline Supervisory Control and Data Acquisition (SCADA) systems (NTSB/SS-05/02). The... indications of a leak on the SCADA interface was the impetus for this study. The NTSB examined 13 hazardous... large pipeline breaks. The line balance processes incorporating SCADA or other technology are geared to...

  7. 77 FR 32631 - Lion Oil Trading & Transportation, Inc., Magnolia Pipeline Company, and El Dorado Pipeline... (United States)


    ... Energy Regulatory Commission Lion Oil Trading & Transportation, Inc., Magnolia Pipeline Company, and El... 385.202 (2011), Lion Oil Trading & Transportation, Inc., Magnolia Pipeline Company, and El Dorado... to Lion subject to certain conditions at specified price spreads. In support of the request for...

  8. Research Activities at IPT, DTU on Resistance Projection Welding

    DEFF Research Database (Denmark)

    Bay, Niels


    Resistance welding processes and among these especially the resistance projection welding is considered an industrially strategic process with increasing applications as alternative to other welding processes, soldering, brazing and mechanical assembling. This is due to increasing requirements...

  9. The impact of welding wire on the mechanical properties of welded joints

    Directory of Open Access Journals (Sweden)

    Magdalena Mazur


    Full Text Available This paper presents results of the mechanical properties of Hardox 450 steel welded joints. These welded joints were made in accordance with welding procedure specifications (WPS, which was prepared and  applied in the Wielton company. Fillers were provided by welding wires with two different diameters. The welding wire was G4Sil with diameter of 1.0 mm and 1.2 mm. The aim of this study was to examine whether the thickness of the welding wire has a direct effect on the properties of welded joints. Test specimens were made in similar parameters of the welding process. Then they were subjected to macroscopic research, tensile strength, impact strength and hardness

  10. Forming Completely Penetrated Welded T-joints when Pulsed Arc Welding (United States)

    Krampit, N. Yu; Krampit, M. A.; Sapozhkov, A. S.


    The paper is focused on revealing the influence of welding parameters on weld formation when pulsed arc welding. As an experimental sample a T-joint over 10 mm was selected. Welding was carried out in flat position, which required no edge preparation but provided mono-directional guaranteed root penetration. The following parameters of welding were subjected to investigation: gap in the joint, wire feed rate and incline angles of the torch along and across the weld axis. Technological recommendations have been made with respect to pulsed arc welding; the cost price of product manufacturing can be reduced on their basis due to reduction of labor input required by machining, lowering consumption of welding materials and electric power.

  11. Simplified welding distortion analysis for fillet welding using composite shell elements

    Directory of Open Access Journals (Sweden)

    Mingyu Kim


    Full Text Available This paper presents the simplified welding distortion analysis method to predict the welding deformation of both plate and stiffener in fillet welds. Currently, the methods based on equivalent thermal strain like Strain as Direct Boundary (SDB has been widely used due to effective prediction of welding deformation. Regarding the fillet welding, however, those methods cannot represent deformation of both members at once since the temperature degree of freedom is shared at the intersection nodes in both members. In this paper, we propose new approach to simulate deformation of both members. The method can simulate fillet weld deformations by employing composite shell element and using different thermal expansion coefficients according to thickness direction with fixed temperature at intersection nodes. For verification purpose, we compare of result from experiments, 3D thermo elastic plastic analysis, SDB method and proposed method. Compared of experiments results, the proposed method can effectively predict welding deformation for fillet welds.

  12. Effect of Pulse Parameters on Weld Quality in Pulsed Gas Metal Arc Welding: A Review (United States)

    Pal, Kamal; Pal, Surjya K.


    The weld quality comprises bead geometry and its microstructure, which influence the mechanical properties of the weld. The coarse-grained weld microstructure, higher heat-affected zone, and lower penetration together with higher reinforcement reduce the weld service life in continuous mode gas metal arc welding (GMAW). Pulsed GMAW (P-GMAW) is an alternative method providing a better way for overcoming these afore mentioned problems. It uses a higher peak current to allow one molten droplet per pulse, and a lower background current to maintain the arc stability. Current pulsing refines the grains in weld fusion zone with increasing depth of penetration due to arc oscillations. Optimum weld joint characteristics can be achieved by controlling the pulse parameters. The process is versatile and easily automated. This brief review illustrates the effect of pulse parameters on weld quality.

  13. Pipeline risk assessment and control: Nigerian National Petroleum Pipeline network experience

    Energy Technology Data Exchange (ETDEWEB)

    Adubi, F.A.; Egho, P.I. [Pipelines and Products Marketing Company Ltd., Nigerian National Petroleum Corporation, Lagos (Nigeria)


    Third party encroachment and corrosion were identified as major causes of pipeline failure in Nigeria. The multi-faceted approach developed by the Nigerian National Petroleum Pipeline Corporation for effective assessment and control of risks to pipelines was described. In essence, information provided from each activity is used to complement information from other activities. This approach led to a better understanding of pipeline status and reduced risk of failures. Aerial surveillance was intensified in order to detect illegal activities, halt them, and remedy any damage. Efforts were also made to intensify corrosion monitoring and pipeline integrity surveys to avoid premature failures. Cathodic protection equipment was found to be only partially effective. due to vandalism and uncontrolled bush burning. 10 figs., 1 ref.

  14. Repair welding of cast iron coated electrodes (United States)

    Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.


    Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.

  15. Risk Communication Concerning Welding Fumes for the Primary Preventive Care of Welding Apprentices in Southern Brazil


    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Cezar Vaz, Joana


    This study’s aim was to assess the perceptions of welding apprentices concerning welding fumes being associated with respiratory and cardiovascular disorders and assess the implementation of risk communication as a primary prevention tool in the welding training process. This quasi-experimental, non-randomized study with before-and-after design was conducted with 84 welding apprentices in Southern Brazil. Poisson Regression analysis was used. Relative Risk was the measure used with a 95% co...

  16. Analysis of factors affecting fractures of rails welded by alumino-thermic welding

    Directory of Open Access Journals (Sweden)

    Sergejs MIKHAYLOVS


    Full Text Available On Latvian Railway the use of the alumino-thermic welding is widespread using the Elektro-Thermit Company technology. Today it is a basic method for rail joints on railway switches. The analysis of the metal structure in the thermic welding and in the thermic welded zone of rails showed that the weld metal had inclusions small pores and nonmetallics. Pores and nonmetallics are not reduce hardness but it is concentrators of stresses and sources of cracks development.

  17. Prediction of numerical distortion after welding with various welding sequences and clampings

    Directory of Open Access Journals (Sweden)

    S. Kastelic


    Full Text Available Welding simulation of a test cover for hydropower plant was made due to very large dimensions of the cover. The main aim was to predict distortion after welding in order to avoid machining the cover. Welding process was simulated with the Sysweld program to keep distortion in desired limits. Various welding sequences and clamping conditions were calculated to reduce the distortion. Calculation of microstructure constituents in virtual complex geometry of joints was also analyzed.

  18. Pipeline four-dimension management is the trend of pipeline integrity management in the future

    Energy Technology Data Exchange (ETDEWEB)

    Shaohua, Dong; Feifan; Zhongchen, Han [China National Petroleum Corporation (CNPC), Beijing (China)


    Pipeline integrity management is essential for today's operators to operate their pipelines safety and cost effectively. The latest developments of pipeline integrity management around the world are involved with change of regulation, industry standard and innovation of technology. And who know the trend of PIM in the future, which can be answered in the paper. As a result, the concept of P4DM was set up firstly in the world. The paper analyzed the pipeline HSE management, pipeline integrity management (PIM) and asset integrity management (AIM), the problem of management was produced, and also the Pipeline 4-dimension Management (P4DM) theory was brought forward. According to P4DM, from the hierarchy of P4DM, the management elements, fields, space and time was analyzed. The main content is P4DM integrate the space geography location and time, control and manage the pipeline system in whole process, anywhere and anytime. It includes the pipeline integrity, pipeline operation and emergency, which is integrated by IT system. It come true that the idea, solution, technology, organization, manager alternately intelligently control the process of management. What the paper talks about included the definition of pipeline 4D management, the research develop of P4DM, the theory of P4DM, the relationship between P4DM and PIM, the technology basis of P4DM, how to perform the P4DM and conclusion. The P4DM was produced, which provide the development direction of PIM in the future, and also provide the new ideas for PetroChina in the field of technology and management. (author)

  19. Influence of the Initial Fiber Orientation on the Weld Strength in Welding of Glass Fiber Reinforced Thermoplastics

    Directory of Open Access Journals (Sweden)

    Isabel Fiebig


    Full Text Available The welding factors are significantly lower in welding of fiber reinforced thermoplastics than in welding of unreinforced thermoplastics due to the fiber orientation in the weld. This paper presents results from investigations on the influence of the initial fiber orientation on the weld strength in hot plate and vibration welding for glass fiber reinforced polypropylene and polyamide 6. Injection molded specimens are compared to specimens with main initial fiber orientation being longitudinal and transverse to the joining direction. The results of CT analysis of the fiber orientation in the weld show the opportunity to achieve a higher weld strength by using specimens with fibers being initially oriented longitudinally to the joining direction. The influence of the initial fiber orientation in the parts to be welded on the weld strength in hot plate welding is more distinct than in vibration welding.

  20. Welding and Joining of Titanium Aluminides (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai


    Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials. PMID:28788113

  1. Laser Peening Effects on Friction Stir Welding (United States)

    Hatamleh, Omar


    Friction Stir Welding (FSW) is a welding technique that uses frictional heating combined with forging pressure to produce high strength bonds. It is attractive for aerospace applications. Although residual stresses in FSW are generally lower when compared to conventional fusion welds, recent work has shown that significant tensile residual stresses can be present in the weld after fabrication. Therefore, laser shock peening was investigated as a means of moderating the tensile residual stresses produced during welding. This slide presentation reviews the effect of Laser Peening on the weld, in tensile strength, strain, surface roughness, microhardness, surface wear/friction, and fatigue crack growth rates. The study concluded that the laser peening process can result in considerable improvement to crack initiaion, propagation and mechanical properties in FSW.

  2. Structural degradation of heterogeneous welded joints

    Directory of Open Access Journals (Sweden)

    Eva Schmidová


    Full Text Available Developing the techniques of welding materials with higher dynamic strength onto the rolling surfaces of rails is one of the options for increasing their operational endurance. The subject of this paper is an analyses of heterogeneous weld interfaces experimentally manufactured by welding medium-carbon austenitic steels onto high-carbon unalloyed pearlitic steels. The analyses focus on examinations of the marginal mixing of the materials at the weld interface and the circumstances under which intercrystalline cracks form in the weld deposit layers. Structural analyses, chemical microanalyses and a hardness assessment were performed in order to identify the corresponding structural changes. The proportion of zonal vs. interdendritic segregation of the alloying elements in the degradation of the welded joint was distinguished. We described the nature of the structural heterogeneities produced, locally connected with the martensitic transformation. The chemical heterogeneity leading to the formation of martensite at grain boundaries was identified as the limiting effect.

  3. Femtosecond fiber laser welding of dissimilar metals. (United States)

    Huang, Huan; Yang, Lih-Mei; Bai, Shuang; Liu, Jian


    In this paper, welding of dissimilar metals was demonstrated for the first time, to the best of our knowledge, by using a high-energy high-repetition-rate femtosecond fiber laser. Metallurgical and mechanical properties were investigated and analyzed under various processing parameters (pulse energy, repetition rate, and welding speed). Results showed that the formation of intermetallic brittle phases and welding defects could be effectively reduced. Strong welding quality with more than 210 MPa tensile strength for stainless steel-aluminum and 175 MPa tensile strength for stainless steel-magnesium has been demonstrated. A minimal heat affected zone and uniform and homogenous phase transformation in the welding region have been demonstrated. This laser-welding technique can be extended for various applications in semiconductor, automobile, aerospace, and biomedical industries.

  4. Welding and Joining of Titanium Aluminides. (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai


    Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing-microstructure-property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  5. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao


    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  6. Passively damped vibration welding system and method (United States)

    Tan, Chin-An; Kang, Bongsu; Cai, Wayne W.; Wu, Tao


    A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.

  7. Friction Stir Welding of Steel Alloys (United States)

    Ding, R. Jeffrey; Munafo, Paul M. (Technical Monitor)


    The friction stir welding process has been developed primarily for the welding of aluminum alloys. Other higher melting allows such, as steels are much more difficult to join. Special attention must be given to pin tool material selection and welding techniques. This paper addresses the joining of steels and other high melting point materials using the friction stir welding process. Pin tool material and welding parameters will be presented. Mechanical properties of weldments will also be presented. Significance: There are many applications for the friction stir welding process other than low melting aluminum alloys. The FSW process can be expanded for use with high melting alloys in the pressure vessel, railroad and ship building industries.

  8. Control of welding distortion during gas metal arc welding of AH36 plates by stress engineering

    NARCIS (Netherlands)

    Pazooki, A.M.A.; Hermans, M.J.M.; Richardson, I.M.


    Welding residual stress and distortion are strongly linked together. One of the ways to control or reduce the welding distortions is the manipulation of the generated stresses during welding, and final residual stresses exist in the workpiece (stress engineering). In this paper, the control of gas

  9. Prediction of the weld pool geometry of TIG arc welding by using ...

    African Journals Online (AJOL)

    The present paper describes fuzzy logic simulation of tungsten inert gas welding (TIG) process to predict the weldment macrostructure zones' shape profile characteristics. The prediction of the weld pool geometry together with the shape of the heat affected zone (HAZ) was accomplished taking into account of TIG welding ...

  10. Numerical evaluation of multipass welding temperature field in API 5L X80 steel welded joints

    Directory of Open Access Journals (Sweden)

    J Nóbrega


    Full Text Available Many are the metallurgical changes suffered by materials when subjected to welding thermal cycle, promoting a considerable influence on the welded structures thermo mechanical properties. In project phase, one alternative for evaluating the welding cycle variable, would be the employment of computational methods through simulation. So, this paper presents an evaluation of the temperature field in a multipass welding of API 5L X80 steel used for oil and gas transportation, using the ABAQUS ® software, based on Finite Elements Method (FEM. During the simulation complex phenomena are considerable including: Variation in physical and mechanical properties of materials as a function of temperature, welding speed and the different mechanisms of heat exchange with the environment (convection and radiation were used. These considerations allow a more robust mathematical modeling for the welding process. An analytical heat source proposed by Goldak, to model the heat input in order to characterize the multipass welding through the GTAW (Gas Tungsten Arc Welding process on root and the SMAW (Shielded Metal Arc Welding process for the filling passes were used. So, it was possible to evaluate the effect of each welding pass on the welded joint temperature field, through the temperature peaks and cooling rates values during the welding process.

  11. JGI Plant Genomics Gene Annotation Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Shengqiang; Rokhsar, Dan; Goodstein, David; Hayes, David; Mitros, Therese


    Plant genomes vary in size and are highly complex with a high amount of repeats, genome duplication and tandem duplication. Gene encodes a wealth of information useful in studying organism and it is critical to have high quality and stable gene annotation. Thanks to advancement of sequencing technology, many plant species genomes have been sequenced and transcriptomes are also sequenced. To use these vastly large amounts of sequence data to make gene annotation or re-annotation in a timely fashion, an automatic pipeline is needed. JGI plant genomics gene annotation pipeline, called integrated gene call (IGC), is our effort toward this aim with aid of a RNA-seq transcriptome assembly pipeline. It utilizes several gene predictors based on homolog peptides and transcript ORFs. See Methods for detail. Here we present genome annotation of JGI flagship green plants produced by this pipeline plus Arabidopsis and rice except for chlamy which is done by a third party. The genome annotations of these species and others are used in our gene family build pipeline and accessible via JGI Phytozome portal whose URL and front page snapshot are shown below.

  12. Bauxite slurry pipeline: start up operation

    Energy Technology Data Exchange (ETDEWEB)

    Othon, Otilio; Babosa, Eder; Edvan, Francisco; Brittes, Geraldo; Melo, Gerson; Janir, Joao; Favacho, Orlando; Leao, Marcos; Farias, Obadias [Vale, Rio de Janeiro, RJ (Brazil); Goncalves, Nilton [Anglo Ferrous Brazil S.A., Rio de Janeiro, RJ (Brazil)


    The mine of Miltonia is located in Paragominas-PA, in the north of Brazil. Bauxite slurry pipeline starts at the Mine of Miltonia and finishes in the draining installation of Alunorte refinery at the port of Barcarena-PA, located approximately 244km away from the mine. The pipeline runs over seven cities and passes below four great rivers stream beds. The system was designed for an underground 24 inches OD steel pipe to carry 9.9 million dry metric tonnes per annum (dMTAs) of 50.5% solid concentration bauxite slurry, using only one pumping station. The system is composed by four storage tanks and six piston diaphragm pumps, supplying a flow of 1680 m3/h. There is a cathodic protection system along the pipeline extension to prevent external corrosion and five pressure monitoring stations to control hydraulic conditions, there is also a fiber optic cable interconnection between pump station and terminal station. Pipeline Systems Incorporated (PSI) was the designer and followed the commissioning program of the start up operations. This paper will describe the beginning of the pipeline operations, technical aspects of the project, the operational experiences acquired in these two years, the faced problems and also the future planning. (author)

  13. Diagnostics and reliability of pipeline systems

    CERN Document Server

    Timashev, Sviatoslav


    The book contains solutions to fundamental problems which arise due to the logic of development of specific branches of science, which are related to pipeline safety, but mainly are subordinate to the needs of pipeline transportation.          The book deploys important but not yet solved aspects of reliability and safety assurance of pipeline systems, which are vital aspects not only for the oil and gas industry and, in general, fuel and energy industries , but also to virtually all contemporary industries and technologies. The volume will be useful to specialists and experts in the field of diagnostics/ inspection, monitoring, reliability and safety of critical infrastructures. First and foremost, it will be useful to the decision making persons —operators of different types of pipelines, pipeline diagnostics/inspection vendors, and designers of in-line –inspection (ILI) tools, industrial and ecological safety specialists, as well as to researchers and graduate students.

  14. Bad Actors Criticality Assessment for Pipeline system (United States)

    Nasir, Meseret; Chong, Kit wee; Osman, Sabtuni; Siaw Khur, Wee


    Failure of a pipeline system could bring huge economic loss. In order to mitigate such catastrophic loss, it is required to evaluate and rank the impact of each bad actor of the pipeline system. In this study, bad actors are known as the root causes or any potential factor leading to the system downtime. Fault Tree Analysis (FTA) is used to analyze the probability of occurrence for each bad actor. Bimbaum's Importance and criticality measure (BICM) is also employed to rank the impact of each bad actor on the pipeline system failure. The results demonstrate that internal corrosion; external corrosion and construction damage are critical and highly contribute to the pipeline system failure with 48.0%, 12.4% and 6.0% respectively. Thus, a minor improvement in internal corrosion; external corrosion and construction damage would bring significant changes in the pipeline system performance and reliability. These results could also be useful to develop efficient maintenance strategy by identifying the critical bad actors.

  15. Bioinformatic pipelines in Python with Leaf (United States)


    Background An incremental, loosely planned development approach is often used in bioinformatic studies when dealing with custom data analysis in a rapidly changing environment. Unfortunately, the lack of a rigorous software structuring can undermine the maintainability, communicability and replicability of the process. To ameliorate this problem we propose the Leaf system, the aim of which is to seamlessly introduce the pipeline formality on top of a dynamical development process with minimum overhead for the programmer, thus providing a simple layer of software structuring. Results Leaf includes a formal language for the definition of pipelines with code that can be transparently inserted into the user’s Python code. Its syntax is designed to visually highlight dependencies in the pipeline structure it defines. While encouraging the developer to think in terms of bioinformatic pipelines, Leaf supports a number of automated features including data and session persistence, consistency checks between steps of the analysis, processing optimization and publication of the analytic protocol in the form of a hypertext. Conclusions Leaf offers a powerful balance between plan-driven and change-driven development environments in the design, management and communication of bioinformatic pipelines. Its unique features make it a valuable alternative to other related tools. PMID:23786315

  16. Underwater pipeline impact localization using piezoceramic transducers (United States)

    Zhu, Junxiao; Ho, Siu Chun Michael; Patil, Devendra; Wang, Ning; Hirsch, Rachel; Song, Gangbing


    Reports indicated that impact events accounted for 47% of offshore pipeline failures, which calls for impact detection and localization for subsea pipelines. In this paper, an innovative method for rapid localization of impacts on underwater pipelines utilizing a novel determination technique for both arrival-time and group velocity (ATGV) of ultrasonic guided waves with lead zirconate titanate (PZT) transducers is described. PZT transducers mounted on the outer surface of a model pipeline were utilized to measure ultrasonic guided waves generated by impact events. Based on the signals from PZT sensors, the ATGV technique integrates wavelet decomposition, Hilbert transform and statistical analysis to pinpoint the arrival-time of the designated ultrasonic guided waves with a specific group velocity. Experimental results have verified the effectiveness and the localization accuracy for eight impact points along a model underwater pipeline. All estimations errors were small and were comparable with the wavelength of the designated ultrasonic guided waves. Furthermore, the method is robust against the low frequency structural vibration introduced by other external forces.

  17. Hazard identification studies applied to oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Savio, Augusto; Alpert, Melina L. [TECNA S.A., Buenos Aires (Argentina)], e-mail:, e-mail:


    In order to assess risks inherent to an Oil Pipeline, it is imperative to analyze what happens 'outside the process'. HAZID (HAZard IDentification) studies are mainly carried out for this purpose. HAZID is a formal study which identifies hazards and risks associated to an operation or facility and enable its acceptability assessment. It is a brainstorming exercise guided by a typical 'Checklist', divided into four Sections: External, Facilities and Health Hazards and Issues pertaining to Project Execution, which are further subdivided into Hazard Categories. For each Category, there are 'Guide-words' and 'Prompts'. Even if an Oil Pipeline Risk Assessment can be performed by means of the above referred 'Checklist', carrying out the actual process can become lengthy and annoying due to the lack of specificity. This work aims at presenting the most suitable 'Checklist' for the identification of Oil Pipeline Risk Assessment, although it could be used for Gas Pipeline Risk Assessment too. Prepared ad hoc, this list, is based on the spill causes established by CONCAWE (CONservation of Clean Air Water in Europe). Performing Oil Pipeline Risk Assessment by means of specially formulated Checklist enables the Study Team to easily identify risks, shortens execution time and provides both accuracy and specificity. (author)

  18. Parameter optimization of flux-aided backing-submerged arc welding by using Taguchi method (United States)

    Pu, Juan; Yu, Shengfu; Li, Yuanyuan


    Flux-aided backing-submerged arc welding has been conducted on D36 steel with thickness of 20 mm. The effects of processing parameters such as welding current, voltage, welding speed and groove angle on welding quality were investigated by Taguchi method. The optimal welding parameters were predicted and the individual importance of each parameter on welding quality was evaluated by examining the signal-to-noise ratio and analysis of variance (ANOVA) results. The importance order of the welding parameters for the welding quality of weld bead was: welding current > welding speed > groove angle > welding voltage. The welding quality of weld bead increased gradually with increasing welding current and welding speed and decreasing groove angle. The optimum values of the welding current, welding speed, groove angle and welding voltage were found to be 1050 A, 27 cm/min, 40∘ and 34 V, respectively.

  19. Width Criterion For Weld-Seam-Tracking Data (United States)

    Lincir, Mark R.


    Image-processing algorithm in "through-torch-vision" (T3V) system developed to guide gas/tungsten arc welding robot along weld seam modified, according to proposal, reducing incidence of inaccurate tracking of weld seam. Developmental system intended to provide closed-loop control of motion of welding robot along weld seam on basis of lines in T3V image identified by use of image-processing algorithm and assumed to coincide with edges of weld seam. Use of width criterion prevents tracking of many false pairs of lines, with consequent decrease in incidence of inaccurate tracking and increase in confidence in weld-tracking capability of robotic welding system.

  20. A System for Complex Robotic Welding

    DEFF Research Database (Denmark)

    Madsen, Ole; Sørensen, Carsten Bro; Olsen, Birger


    This paper presents the architecture of a system for robotic welding of complex tasks. The system integrates off-line programming, control of redundant robots, collision-free motion planning and sensor-based control. An implementation for pipe structure welding made at Odense Steel Shipyard Ltd......., Denmark, demonstrates the system can be used for automatic welding of complex products in one-of-a-kind production....

  1. Numerical methods in simulation of resistance welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi


    Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...

  2. Heavy multi-pass TIG welding


    Maske, Tomas


    This study aims to find the maximum, usable, feed limit at different arc-energies and use the findings in multi-pass welding planning for robotic welding, taking into consideration the high controllability of robot movements. A combined studies using numerical analyses and practical experiments to calculate the feed limits for different arc energies. Each weld where analysed both mathematical, physical and thru observation. The combined results for one experiment will form the bases for th...

  3. Occupational rhinitis due to steel welding fumes. (United States)

    Castano, Roberto; Suarthana, Eva


    Exposure to welding fumes is a recognized respiratory hazard. Occupational asthma but not occupational rhinitis has been documented in workers exposed to steel welding fumes. We report a 26-year-old male with work-related rhinitis symptoms as well as lower airways symptoms suggestive of occupational asthma and metal fume fever associated with exposure to steel welding fumes. The diagnosis of occupational rhinitis was confirmed by specific inhalation challenge. © 2014 Wiley Periodicals, Inc.

  4. Effects Of Heat Sinks On VPPA Welds (United States)

    Nunes, Arthur C.; Steranka, Paul O., Jr.


    Report describes theoretical and experimental study of absorption of heat by metal blocks in contact with metal plate while plate subjected to variable-polarity plasma-arc (VPPA) welding. Purpose of study to contribute to development of comprehensive mathematical model of temperature in weld region. Also relevant to welding of thin sheets of metal to thick blocks of metal, heat treatment of metals, and hotspots in engines.

  5. Controlling Arc Length in Plasma Welding (United States)

    Iceland, W. F.


    Circuit maintains arc length on irregularly shaped workpieces. Length of plasma arc continuously adjusted by control circuit to maintain commanded value. After pilot arc is established, contactor closed and transfers arc to workpiece. Control circuit then half-wave rectifies ac arc voltage to produce dc control signal proportional to arc length. Circuit added to plasma arc welding machines with few wiring changes. Welds made with circuit cleaner and require less rework than welds made without it. Beads smooth and free of inclusions.

  6. Friction stir welding of single crystal aluminium

    DEFF Research Database (Denmark)

    Fonda, Richard Warren; Wert, John A.; Reynolds, A.P.


    Friction stir welds were prepared in different orientations in an aluminium single crystal. The welds were quenched to preserve the microstructure surrounding the tool and then electron backscattered diffraction was used to reveal the generation of grain boundaries and the evolution...... of crystallographic texture around the tool in each weld. The extent of both dynamic recrystallisation and conventional recrystallisation varied considerably as a function of weld orientation. As the base plate begins to interact with the deformation field surrounding the tool, regions of the single crystal rotate...

  7. Improving Fatigue Performance of AHSS Welds

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [ORNL; Yu, Xinghua [ORNL; ERDMAN III, DONALD L [ORNL; Wang, Yanli [ORNL; Kelly, Steve [ArcelorMittal USA; Hou, Wenkao [ArcelorMittal USA; Yan, Benda [ArcelorMittal USA; Wang, Zhifeng [Colorado School of Mines, Golden; Yu, Zhenzhen [Colorado School of Mines, Golden; Liu, Stephen [Colorado School of Mines, Golden


    Reported herein is technical progress on a U.S. Department of Energy CRADA project with industry cost-share aimed at developing the technical basis and demonstrate the viability of innovative in-situ weld residual stresses mitigation technology that can substantially improve the weld fatigue performance and durability of auto-body structures. The developed technology would be costeffective and practical in high-volume vehicle production environment. Enhancing weld fatigue performance would address a critical technology gap that impedes the widespread use of advanced high-strength steels (AHSS) and other lightweight materials for auto body structure light-weighting. This means that the automotive industry can take full advantage of the AHSS in strength, durability and crashworthiness without the concern of the relatively weak weld fatigue performance. The project comprises both technological innovations in weld residual stress mitigation and due-diligence residual stress measurement and fatigue performance evaluation. Two approaches were investigated. The first one was the use of low temperature phase transformation (LTPT) weld filler wire, and the second focused on novel thermo-mechanical stress management technique. Both technical approaches have resulted in considerable improvement in fatigue lives of welded joints made of high-strength steels. Synchrotron diffraction measurement confirmed the reduction of high tensile weld residual stresses by the two weld residual stress mitigation techniques.

  8. New materials for welding and surfacing (United States)

    Kozyrev, N. A.; Galevsky, G. V.; Kryukov, R. E.; Titova, D. A.; Shurupov, V. M.


    The paper provides description of research into the influence of new materials and technologies on quality parameters of welds and deposited metal carried out in the research and production centre “Welding processes and technologies”. New welding technologies of tanks for northern conditions are considered, as well as technologies of submerged arc welding involving fluxing agents AN - 348, AN - 60, AN - 67, OK.10.71 and carbon-fluorine containing additives; new flux cored wires and surfacing technologies, teaching programs and a trainer for welders are designed.

  9. Friction Pull Plug Welding in Aluminum Alloys (United States)

    Brooke, Shane A.; Bradford, Vann


    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  10. Emissions of chromium (VI) from arc welding. (United States)

    Heung, William; Yun, Myoung-Jin; Chang, Daniel P Y; Green, Peter G; Halm, Chris


    The presence of Cr in the +6 oxidation state (Cr[VI]) is still observed in ambient air samples in California despite steps taken to reduce emissions from plating operations. One known source of emission of Cr(VI) is welding, especially with high Cr-content materials, such as stainless steels. An experimental effort was undertaken to expand and update Cr(VI) emission factors by conducting tests on four types of arc-welding operations: gas-metal arc welding (GMAW), shielded metal arc welding (SMAW), fluxcore arc welding, and pulsed GMAW. Standard American Welding Society hood results were compared with a total enclosure method that permitted isokinetic sampling for particle size-cut measurement, as well as total collection of the aerosol. The fraction of Cr(VI) emitted per unit mass of Cr electrode consumed was determined. Consistent with AP-42 data, initial results indicate that a significant fraction of the total Cr in the aerosol is in the +6 oxidation state. The fraction of Cr(VI) and total aerosol mass produced by the different arc welding methods varies with the type of welding process used. Self-shielded electrodes that do not use a shield gas, for example, SMAW, produce greater amounts of Cr(VI) per unit mass of electrode consumed. The formation of Cr(VI) from standard electrode wires used for welding mild steel was below the method detection limit after eliminating an artifact in the analytical method used.

  11. Melting Efficiency During Plasma Arc Welding (United States)

    McClure, J.C.; Evans, D. M.; Tang, W.; Nunes, A. C.


    A series of partial penetration Variable Polarity Plasma Arc welds were made at equal power but various combinations of current and voltage on 2219 aluminum. Arc Efficiency was measured calorimetrically and ranged between 48% and 66%. Melting efficiency depends on the weld pool shape. Increased current increases the melting efficiency as it increases the depth to width ratio of the weld pool. Higher currents are thought to raise arc pressure and depress the liquid at the bottom of the weld pool causing a more nearly two dimensional heat flow condition.

  12. Laser-TIG Welding of Titanium Alloys (United States)

    Turichin, G.; Tsibulsky, I.; Somonov, V.; Kuznetsov, M.; Akhmetov, A.


    The article presents the results of investigation the technological opportunity of laser-TIG welding of titanium alloys. The experimental stand for implementation of process with the capability to feed a filler wire was made. The research of the nature of transfer the filler wire into the welding pool has been demonstrated. The influence of distance between the electrode and the surface of the welded plates on the stability of the arc was shown. The relationship between welding velocity, the position of focal plane of the laser beam and the stability of penetration of plates was determined.

  13. Welding the AT-400A Containment Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, E.


    Early in 1994, the Department of Energy assigned Sandia National Laboratories the responsibility for designing and providing the welding system for the girth weld for the AT-400A containment vessel. (The AT-400A container is employed for the shipment and long-term storage of the nuclear weapon pits being returned from the nation's nuclear arsenal.) Mason Hanger Corporation's Pantex Plant was chosen to be the production facility. The project was successfully completed by providing and implementing a turnkey welding system and qualified welding procedure at the Pantex Plant. The welding system was transferred to Pantex and a pilot lot of 20 AT-400A containers with W48 pits was welded in August 1997. This document is intended to bring together the AT-400A welding system and product (girth weld) requirements and the activities conducted to meet those requirements. This document alone is not a complete compilation of the welding development activities but is meant to be a summary to be used with the applicable references.

  14. Small Bore Piping Socket Weld Evaluation System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Min; Cho, Hong Seok; Choi, Sang Hoon; Cho, Ki Hyun; Lee, Jang Wook [Korea Plant Service and Enginccring Co., Seongnam (Korea, Republic of)


    Kori unit 3 had stopped operation due to leakage at Steam Generator drain line socket weld on June 6, 2008. The Cause of socket weld damage was known as a fatigue crack. According to this case, all socket welds located in RCS pressure boundary are carrying out Radiographic Testing. But to inspect socket welds by RT has some problems. The result of EPRI study showed that RT has limitation to find flaws at socket welds.The orientation of flaws has big influence on RT inspection capability and there is not enough space at socket welds for RT, dose problems as well. Although the gap between coupling and pipe at socket welds must follow up code, surface inspection can't inspect the gap. If there is absence of the gap, socket welds are damaged during operation. The gap should be identified by RT but the distance of gap can't be measured. As this paper, the ultrasonic inspection system was introduced to figure out indication and gap in the socket welds.

  15. The Dark Energy Survey Image Processing Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Morganson, E.; et al.


    The Dark Energy Survey (DES) is a five-year optical imaging campaign with the goal of understanding the origin of cosmic acceleration. DES performs a 5000 square degree survey of the southern sky in five optical bands (g,r,i,z,Y) to a depth of ~24th magnitude. Contemporaneously, DES performs a deep, time-domain survey in four optical bands (g,r,i,z) over 27 square degrees. DES exposures are processed nightly with an evolving data reduction pipeline and evaluated for image quality to determine if they need to be retaken. Difference imaging and transient source detection are also performed in the time domain component nightly. On a bi-annual basis, DES exposures are reprocessed with a refined pipeline and coadded to maximize imaging depth. Here we describe the DES image processing pipeline in support of DES science, as a reference for users of archival DES data, and as a guide for future astronomical surveys.

  16. Digitally assisted pipeline ADCs theory and implementation

    CERN Document Server

    Murmann, Boris


    List of Figures. List of Tables. Acknowledgements. Preface. 1: Introduction. 1. Motivation. 2. Overview. 3. Chapter Organization. 2: Performance Trends. 1. Introduction. 2. Digital Performance Trends. 3. ADC Performance Trends. 3: Scaling Analysis. 1. Introduction. 2. Basic Device Scaling from a Digital Perspective. 3. Technology Metrics for Analog Circuits. 4. Scaling Impact on Matching-Limited Circuits. 5. Scaling Impact on Noise-Limited Circuits. 4: Improving Analog Circuit Efficiency. 1. Introduction. 2. Analog Circuit Challenges. 3. The Cost of Feedback. 4. Two-Stage Feedback Amplifier vs. Open-Loop Gain Stage. 5. Discussion. 5: Open-Loop Pipelined ADCs. 1. A Brief Review of Pipelined ADCs. 2. Conventional Stage Implementation. 3. Open-Loop Pipeline Stages. 4. Alternative Transconductor Implementations. 6: Digital Nonlinearity Correction. 1. Overview. 2. Error Model and Digital Correction. 3. Alternative Error Models. 7: Statistics-Based Parameter Estimation. 1. Introduction. 2. Modulation Approach. 3. R...

  17. V-GAP: Viral genome assembly pipeline

    KAUST Repository

    Nakamura, Yoji


    Next-generation sequencing technologies have allowed the rapid determination of the complete genomes of many organisms. Although shotgun sequences from large genome organisms are still difficult to reconstruct perfect contigs each of which represents a full chromosome, those from small genomes have been assembled successfully into a very small number of contigs. In this study, we show that shotgun reads from phage genomes can be reconstructed into a single contig by controlling the number of read sequences used in de novo assembly. We have developed a pipeline to assemble small viral genomes with good reliability using a resampling method from shotgun data. This pipeline, named V-GAP (Viral Genome Assembly Pipeline), will contribute to the rapid genome typing of viruses, which are highly divergent, and thus will meet the increasing need for viral genome comparisons in metagenomic studies.

  18. Hubble Legacy Archive (HLA) Pipeline Progression (United States)

    Anderson, Rachel E.; Casertano, S.; Lindsay, K.


    The HLA maintains a strong commitment to continuing improvement of our Hubble Space Telescope data processing pipelines with the goal of generating better science-ready data products. The HLA image processing pipeline is transitioning from the use of MultiDrizzle to AstroDrizzle for image registration and combination. It is expected that this change will allow for the creation of higher quality science products with improved astrometric solutions. Headerlets, a newly developed tool for AstroDrizzle, will be utilized and made available to simplify access to multiple astrometric solutions for a given data set. The capabilities of AstroDrizzle will allow for functionally simplified data processing, standardizing and streamlining the data reduction process and making it easier for users to reproduce our results. We are beginning with the HLA WFC3 data processing pipeline, and then plan to extend its application to other HST instrument data.

  19. Fatigue life evaluation of a cracked pipeline pipe operating under variable; Estudo da vida em fadiga com variacao de pressao interna em tubos com defeitos

    Energy Technology Data Exchange (ETDEWEB)

    Betanzos, J.; Mattei, F. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil); Strohaecker, T. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Programa de Pos-graduacao em Engenharia de Minas, Metalurgia e Materiais; Marinho, R.; Hoppe, R.; Donato, G. [PETROBRAS, Rio de Janeiro, RJ (Brazil)


    Fatigue cracks in welded joints are commonly found in gas and oil pipelines and usually pumping is interrupted for repair. The strength of welded joints with defects, and consequently, the useful life of a pipeline, is an important information that could lead to great improvements in the reliability. To evaluate the working conditions determined by standards, specimens with 22'' diameter and 1/2'' wall thickness API 5L X60 pipes were used. Two semi-elliptical cracks were electro spark machined, with 50% and 25% of the tube wall thickness depths and a length/depth ratio of 1/20. Both defects were located in the HAZ of the tube longitudinal seam weld. Applying a cyclic internal pressure it was possible to propagate a fatigue crack until a through-thickness condition. The results show that the pressures to initiate crack propagation are too much higher than the pressures allowed by the standards for this kind of defect. (author)

  20. Welding shield for coupling heaters (United States)

    Menotti, James Louis


    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.