PR-186-104504-R01 Guidelines to Address Pipeline Construction Quality Issues

The objective of this project was to develop guidelines pertaining to these issues and how they should be addressed in the field. A review of recent incidents involving girth weld failures in newly-constructed pipelines indicate that all incidents involved production welds in pipelines constructed using conventional techniques (i.e., using cellulosic-coated electrodes) – particularly welds at wall thickness transitions – and repair and tie-in welds made using cellulosic-coated electrodes in pipelines otherwise constructed using mechanized gas-metal arc welding. None of the recent failures involved mechanized gas-metal arc welds. Many of these failures were attributed, at least in part, to hydrogen-assisted cracking and high stresses. A review of the factors related to hydrogen cracking in modern pipeline girth welds indicates that managing weld hydrogen levels and the stresses acting on these welds is the most appropriate strategy for controlling the risk of hydrogen-assisted cracking, which became the primary focus of this project.