The world around us is constantly changing, and pipeline construction is no different. A number of developments have expanded our options for welding pipelines over the years, and the industry continues to introduce new technology. In this presentation, we will look at the latest in welding technology and discuss the options available for mechanized welding. We'll look at the factors influencing when mechanized welding should be considered. We will also take a glimpse into the future and look at some of the interesting technology being developed now for pipeline welding.

Over the last ten years a number of large diameter Grade X80 pipelines have been constructed in Canada, USA, Europe and China. The use of high strength line pipe can provide significant cost savings particularly for pipelines constructed using mechanized welding in combination with Automated Ultrasonic (AUT) inspection and Engineering Critical Assessment (ECA) flaw acceptance criteria. Although the use of Grade X80 line pipe is now well established for traditional pipeline designs (i.e., stress based design pipelines operating at modest pressures) there are still challenges for Grade X80 pipelines designed for high strain loading or high pressure operation. This presentation will present the current status of Grade X80 pipeline technology and highlight the technical challenges that must be addressed before considering Grade X80 for strain based design pipeline applications or high pressure pipelines.

Prior to joining Det Norske Veritas, Bruce was a Technology Leader at Edison Welding Institute (EWI) and a Senior Engineer at Panhandle Eastern Pipeline Co. He has been involved in pipeline welding research and development continuously since his graduation from Ohio State University in 1981, where he earned a B.S. in welding engineering. During his tenure at EWI, he spent a four-month secondment at The Welding Institute in the UK. His areas of interest include repair welding, inspection techniques, and failure analysis.

Recently there has been a lot of research to determine whether such advanced welding processes like hybrid laser welding and friction stir welding are viable options for pipeline construction from a productivity standpoint. One of the largest hurdles for a company that is interested in implementing these processes is the fact that no pipeline welding codes currently have these procedure qualification requirements for either of these welding processes. To address this potential obstacle the ASME Section IX sub-committee has proposed procedure and welding operator qualification requirements for both hybrid laser-GMAW welding and friction stir welding. This presentation discusses what the proposed requirements are for both welding processes to disseminate the information prior to the release of the next edition of ASME Section IX.

Despite significant investment, one-shot welding and power beam processes have not been very successful in achieving real benefits in pipeline construction. The most promising of the newer and more innovative welding processes is the hybrid Laser/arc welding process (HLAW), which can complete 5G welds, assure weld soundness, material properties, and an acceptable geometric profile. The combination of new lasers and pulsed gas metal arc welding (GMAW-P) power source technologies have led to important innovations in the HLAW process that have been shown to increase the travel speed for successful root pass welding. In particular, high power Yb fiber lasers with high efficiency (25% compared with 3% for a Nd:YAG laser) allow a 1OkW laser to be built the size of a refrigerator. This allows for previously unheard of portability and power levels for use outside the laboratory and 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, pipe lines and develop 5G welding procedures for X80 and XI00 pipe, including mechanical testing to API 1104. The main goal of a cost-matched JIP was to develop a prototype hybrid high power Yb fiber laser and GMAW head based on a commercially available bug and band system (Figure 1). Under the DOT project, the subject of this paper, innovative technologies for pipeline girth welding were developed. External hybrid root pass welding techniques were developed for variations of laser power (4-10 kW) and root face thickness (4-8 mm) as this has the greatest potential to meet existing pipeline integrity requirements and facilitate the use of new high power Yb fiber lasers for high speed HLAW of pipe root passes. Following the integration of the Yb fiber laser and GMAW head onto a commercially available bug and band system (CRC-Evans P450) the system was used to achieve full penetration welds with a 4 mm root at a travel speed of 2.3 m/min. The root welds were made in a "double down" configuration using laser powers up to 1OkW and travel speeds up to 3 m/min. The final objective of the project is to demonstrate the hybrid LBW/GMAW system under field conditions.

The repair and remediation of in-service pipelines is a safety critical process that is closely controlled, but at the same time it must be performed with cost-effective techniques. For repair of large diameter pipelines, the current practice of using of manual welding is time-consuming and the risk of operator error is great due to the long welding times required and subsequent welder fatigue. Similarly, higher strength pipe, due to their chemical and mechanical properties, require strict adherence to welding procedures including precise weld bead placement which is necessary to properly temper underlying weld beads. EWI led a project co-funded by the U.S. Department of Transportation's Pipeline Hazardous Material Safety Administration and Pipeline Research Council International to extend the current capabilities by developing an automated welding system prototype for use on in-service natural gas transmission pipelines. The major objective of this program was to develop an automated welding system prototype for in-service pipelines that features a real-time, adaptive control tracking system to ensure reliable welding conditions. The resultant mechanized system has a multi-axis welding carriage designed for use with gas metal arc welding (GMAW).

Shielded metal arc welding or SMAW has been slowly evolving in the US and abroad. These changes have occurred in consumables and equipment. This presentation will discuss how the welders have coped with the change in filler metals and the introduction of inverter power sources to transmission pipelines.

Literally thousands of miles of cross country gas and oil transmission lines are welded each year in the US using SMAW electrodes. Historically, the cellulosic types have been used. However, with the move toward higher strength steels to reduce wall thicknesses and increase operating pressures, alternatives to cellulosic electrodes are required that maintain an acceptable balance between quality and productivity. One option is using wire, but this is often prohibitive due to equipment costs and lack of trained welders. Another option is to use low hydrogen electrodes, but the fear is there will be an extreme loss in productivity. Studies were conducted to compare the mechanical properties, welding time, productivity differences, and total effect on costs between the potential SMAW electrodes – E8010-P1 (cellulosic electrodes for vertical down welding), E8045-P2 (basic low hydrogen electrodes for vertical down welding), and E8016-G (basic low hydrogen electrodes for vertical up welding). The results of this work will be presented.

Information coming soon.

Full scale pipeline girth weld fatigue testing to determine S-N performance has historically been done using girth welds made under controlled conditions at the subcontractor's shore based welding procedure development laboratory by skilled welding operators. The fatigue test girth welds are high quality but otherwise are representative of production girth welds with respect to pipe end tolerance and material fracture resistance.

Hydrogen-induced cracking is one of the greatest threats to the integrity of transmission pipeline applications. It can lead to downtime for rework, additional costs for labor and potential delays in construction. This presentation will examine the manner in which hydrogen can be introduced into the weld, so as to help contractors mitigate the risk. It will specifically provide solutions for eliminating hydrogen-induced cracking through proper filler metal selection, handling and storage; best pre-, post- and interpass- heat treatment practices; various welding techniques; and more.

Over the past several years, oil and gas pipeline construction has been in the national spotlight. While TransCanada's Keystone XL project was drawn into political debates, several other pipeline incidents focused the industry's attention on issues such as leak detection, automatic shut off valves, integrity management and other operational requirements. Additionally, a number of construction practices have been under review by the Pipeline and Hazardous Materials Safety Administration (PHMSA), which is part of the U.S. Department of Transportation. In this presentation, the speaker will review some of the recent findings and recommendations as they relate to the welding of onshore pipelines.

The welding technology needs of a pipeline vary depending on specific project details and conditions. Cost minimization and quality assurance are common important factors on projects. Historically, mechanized welding has proven itself in these regards, essentially revolutionizing the way onshore pipelines are built. Mechanized welding advantages include high productivity, high repeatability, weld parameter range control, the ability to automate seam tracking for some weld passes, and the ability to keep electronic records of weld parameters for produced welds. For these and many other reasons, the proportion of onshore pipeline projects using mechanized welding is likely to increase, as techniques advance and pipeline construction contractors become more comfortable with their use. In addition, the proportion of welding applications using mechanization within a given project is likely to increase, for applications like tie-ins. Mechanized welding technology options available from RMS Welding Systems for mainline and tie-in welding will be presented along with their advantages and application ranges in terms of weld type, line pipe grade, diameter, wall thickness, project conditions, and other factors. Fit up techniques with their associated root pass application (internal versus external root), deposition strategy, power sources and torch manipulation will be discussed, and a link from these strategies to weld integrity and mechanical properties will be made, with discussion of high strength pipe applications up to API 5L X100/CSA Z245.1 Grade 690.

In this presentation, three developments in ultrasonic technology, namely, Time-Of-Flight-Diffraction, Phased Array, and Encoded Scans & Automation, will be discussed. Development in Code provisions for technology advancements such as acceptance of alternate test methods and Code acceptance criteria will then be discussed. Other topics will include calibration methods of advanced equipment using conventional techniques; changes to inspection & scanning techniques followed by method comparisons; data collection & imagery presentation formats; and, finally, reporting.

Information coming soon.

After introducing the challenges involved with the welding of CRA pipelines and risers, Serimax will present how new technology development will help achieving the highest quality expected for such lines. Taking the example of a CRA line welded on a spool base, we will follow the process and identify at each step the solutions offered to successfully assemble and lay this pipeline. This will start with beveling and having an accurate bevel control and pipe end measurement, followed by our latest development in back purging internal line-up clamp. The next step will be welding using our latest version of the Saturnax welding system for the mainline and the newly developed Externax (an external welding clamp) for the tie-in welds, onshore and offshore. The cycle will end with the presentation of CleverWeld, our solution for integrated quality control, data logging and management of all these operations into one interface.

Pipeline welding systems currently marketed chiefly use the Gas Metal Arc Welding (GMAW) process in short-circuiting mode. Machine GMAW pipeline welding systems traditionally require a special narrow groove bevel geometry requiring field remachining of pipe ends. When using equipment designed for "automatic" pipe welding, joint preparation and joint fit-up must be near perfect. Care has to be taken at the area of the seam weld (longitudinal- or spiral welded pipe). The root pass may be done using a special ID welding machine. A second alternative is to weld the root using an external Head (Bug), requiring a special ID clamp with copper "shoes". This technique also requires a special "J" bevel. Both approaches require specialized equipment. The copper backing technique is not allowed in many countries. Hot, fill, and cap passes are done using two weld Heads mounted to the pipe using a band simultaneously welding downhill on either side of the pipe. An alternative is to use the standard, as-delivered 30 "V" bevel. Magnatech pioneered a hybrid "mechanized" technique, now used extensively for 10 years. The root pass is made using a new generation of waveform controlled GMAW process, such as Lincoln Electric's STT. STT overcomes the limitations of short-circuit GMAW using sophisticated electronic control of the metal transfer process. The root pass is made manually using a standard "semiautomatic" GMAW wire feeder and torch. With proper welder training, STT is forgiving and ensures that the manual welder can make a perfect, defect-free, root pass every time. Root deposits are properly fused with the sidewalls, with virtually no spatter. Waveform controlled power sources deposit a sufficiently heavy root bead, allowing the immediate use of the FCAW process for the subsequent (hot) pass without repenetration. STT is a solid wire process, and thus eliminates slag removal and grinding. Welding the root pass with semiautomatic equipment is more tolerant of mismatch and fit-up variability. To compensate for the greater volume of weld metal required, a higher deposition rate process is used - Flux Core Arc Welding (FCAW). FCAW welding is done uphill. Magnatech's Pipeliner "Bug and Band" system is designed for FCAW pipe welding. Weld quality is excellent, with negligible defect and repair rates (less than 1.0%).