ARCO Oil & Gas Company — Pipeline Safety Interpretation

Page 1Mr. Tom Schmld Environmental Engineer ARCO Oil & Gas Company South Texas District P.O. Box 1346 Houston, Texas 77001 Dear Mr. Schmld: Your letter dated September 24, 1979, to Mr. Robert F. Aubry, was forwarded to this office for reply. You requested an interpretation of section 195.1(b)(3) of 49 CFR Part 195. You raised the question concerning the pressure to be used to determine whether a pipeline operates at a stress level at 20 percent or less of the specified minimum yield strength pressure are to be included in this determination. Normal fluctuations are excluded from the determination of the operating pressure to be used to determine compliance with section 195.1(b)(3). The operating pressure intended for use in section 195.1(b)(3) is conceptually consistent with the " Maximum operating pressure as given in section 195.406, wherein surges and other variations from normal operations " are excepted in section 195.406(a). You also raised the question concerning whether Part 195 is applicable only during the time a pipeline operates above the 20 percent stress level. Please be advised that Part 195 is applicable all of the time if the pipeline operates above the 20 percent stress level only part of the time. Also, Part 195 applies to a pipeline that always operates at the 20 percent level or less if that pipeline is part of a carrier's overall pipeline system that is subject to Part 195. Sincerely, Cesar DeLeon Associate Director for Pipeline Safety Regulation Materials Transportation Bureau DB C:\WP51\INTERPRT\195\1\79-12-14 1#