The Department of Transportation (DOT) is calling on owners and operators of recently constructed large-diameter natural gas pipelines and hazardous liquid pipelines to examine their systems for potential girth weld defects.

In an advisory bulletin published in the Federal Register Wednesday, the DOT’s Pipeline and Hazardous Material Safety Administration (PHMSA) said it found girth weld failures due to welding quality issues when it reviewed several pipeline projects constructed in 2008 and 2009 with 20-inch or greater diameter, grade X70 and higher line pipeline. A girth weld joins together two segments of pipeline.

“Metallurgical testing results of failed girth welds in pipe wall thickness transitions have found pipe segments with line pipe weld misalignment, improper bevel and wall thickness transitions, and other improper welding practices that occurred during construction,” the agency said in the advisory.

“Many of the integrity issues with transition girth welds were present on pipelines being constructed in hilly terrain and high-stress concentration locations such as at crossings, streams and sloping hillsides with unstable soils,” the PHMSA noted.

Contact Alan Mayberry at (202) 366-5124 or at alan.mayberry@dot.gov for further information.

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