An Update on Mechanized Gas Metal Arc Welding (GMAW) of Pipelines

Industry standards for pipeline welding generally had their origins in cellulosic welding of onshore pipelines. Over the years they have been adapted to include new material grades, processes and more demanding applications. Even though mechanized gas metal arc welding (GMAW) is the dominant process for offshore pipelines, and is widely used for large diameter long distance cross-country pipelines, industry standards still do not fully reflect the subtleties of this process. This results in owners and operators having to issue amending company specifications. Moreover, there have been continual technical developments in equipment and control technology which makes mechanized GMAW ever more sophisticated. The European Pipeline Research Group (EPRG) identified a need to develop guidelines focused on mechanized GMAW. The work has reviewed the main industry standards and also had input from company specifications. It reviewed typical equipment and consumables, procedure and welder qualification, typical equipment including ancillaries, production welding, inspection and testing, acceptance criteria and repair options.