The Department of Transportation/Pipeline Hazardous Materials Safety Administration (PHMSA) issued Advisory Bulletin, ADB-09-01, “Pipeline Safety: Potential Low and Variable Yield and Tensile Strength and Chemical Composition Properties in High Strength Line Pipe” to owners and operators of natural gas pipeline and hazardous liquid pipeline systems. This advisory bulletin pertains to microalloyed high strength line pipe grades, generally Grade X-70 and above.

The Federal pipeline safety regulations in 49 CFR Parts 192 and 195 require operators of natural gas transmission, gas distribution, and hazardous liquids pipeline systems to use pipe manufactured by a listed specification in the design of pipelines in accordance with Sec. 192.7, 192.55 (a), 192.105, and Sec. 195.3, 195.106, and 195.112. Tests that have been conducted on line pipe that has been installed in pipeline systems have shown that some of the pipe material has yield strengths, tensile strengths, and/or chemical compositions that do not meet the requirements of the American Petroleum Institute, Specification for Line Pipe–5L, (API 5L), for PSL 2 and the specified pipe grade. PHMSA recently reviewed metallurgical testing results from several recent projects indicating pipe joints produced from plate or coil from the same heat may exhibit variable chemical and mechanical properties by as much as 15% lower than the strength values specified by the pipe manufacturer.

PHMSA wants to ensure that owners and operators of recently constructed pipeline systems are aware of the need to investigate whether their pipelines contain joints of pipe that do not meet minimum specification requirements.

For more information or a copy of ADB-09-01, contact Jessica Roger.