{"operation":"document","citation":"PI-91-031","title":"Vinson & Elkins — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1991-10-22","effective_on":null,"summary":"PI-91-031 response to Vinson & Elkins concerning 192.243, 192.611.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-91-031.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-91-031.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-91-031","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1991/PI91031.pdf","body":"<<<PAGE 1>>>\n\nOct 22 1991\nMr. Gary M. Kotara\nVinson & Elkins\nThe Willard Office Building\n1455 Pennsylvania Avenue, N.W.\nWashington, DC 20004-1007\nDear Mr. Kotara:\nWe have considered LFC Pipeline Corporation's petition, dated March 15, 1991, (Pet. No. P-91-1W),\nwhich you submitted by letter of the same date. This petition requests waiver of certain welding\nrequirements of 49 CFR 192.243(d)(3) and (f) for a pipeline system in Sutter County, California. The\npipeline system transports gas from local wells to two congeneration plants.\nIt is our policy not to waive compliance with a pipeline safety standard unless compliance would be\ninappropriate under the circumstances. In addition, we may not waive compliance with a safety standard\nissued under the Natural Gas Pipeline Safety Act of 1968 (NGPSA) unless we determine the waiver \"is\nnot inconsistent with gas pipeline safety\" (49 App. U.S.C. 1672 (d)). So in evaluating your first waiver\nrequest, we have considered the circumstances that affect compliance and how noncompliance would\naffect safety. As explained below, we have denied this request.\nWe also explain below why we consider waivers unnecessary under the circumstances involved in the two\nother requests. We have neither granted nor denied these requests.\nThe first waiver request concerns four segments of the pipeline system, which the petition identifies as\nAreas 1-4. For these segments, the petition requests waiver of the requirement of 192.243(d)(3) to test\nnondestructively 100 percent of the girth welds within Class 3 locations or highway rights-of-way; or at\nleast 90 percent if 100 percent is impracticable. The petition states that in these four segments, tie-in\nwelds were all x-rayed, but only 30 to 75 percent of the other girth welds were x-rayed.\nOf the adverse consequences the petition projects to result from post-construction compliance in Areas 1-\n4, we regard additional cost and inconvenience to landowners and road users as most likely to occur.\nBut, we do not think these consequences are so onerous that compliance would be inappropriate. They\ntypically occur when long pipeline segments in populated areas are replaced or rehabilitated to meet Part\n192 safety requirements. In addition, the projected cost ($280,000) seems overstated, because it includes\nthe cost of hydrostatically testing the affected segments of pipeline. Under Part 192, LFC Pipeline\nCorporation could x-ray girth welds in the affected segments without additional hydrostatic testing. If x-\nray tests reveal a defective girth weld that is repaired later by removing the weld, the short replacement\npipe may be hydrostatically tested separately, and tie-in welds need not be hydrostatically tested.\nAs for the projected adverse consequences of depressurizing the affected segments, Part 192 allows x-ray\ntests of girth welds that are under pressure. Depressurization would be necessary if LFC Pipeline\nCorporation removes a defective girth weld. To minimize the impact on customers, such removal could\nbe done after the peak-use season, provided a hazardous leak is not present.\n91-10-22.doc 192.243, 192.611\n\n<<<PAGE 2>>>\n\nThe petition does not persuade us that safety would not be jeopardized by failing to complete all the\nrequired x-ray tests in the affected segments. Part 192 requires both hydrostatic testing and\nnondestructive testing for the safety of these segments. Thus, we cannot conclude the segments are safe\nmerely because they have passed a hydrostatic test. Even a hydrostatic test that exceeds 90 percent of\nSMYS is not an adequate substitute for x-ray tests of girth welds, because hydrostatic testing is incapable\nof detecting all unacceptable weld defects that could contribute to weld failure. LFC Pipeline\nCorporation's alleged low defect rate on x-rayed girth welds is commendable. Yet, if we assume the\nsame rate applies to the girth welds not x-rayed, a probability remains that some unacceptable weld\ndefects exist in the affected segments. We cannot overlook this threat to safety in the affected segments,\nespecially since Areas 1-4 are populated areas or near highways.\nAlso, 192.611 does not, as the petition asserts, allow operators to uprate pipelines (increase their\nmaximum allowable operating pressures) through hydrostatic testing (see 192.611(a)(3)(ii)). Subpart K\nof Part 192 governs uprating. Section 192.611 does allow certain existing pipeline segments that were\nnot constructed to Class 3 standards to operate in Class 3 locations if their integrity is confirmed by\nhydrostatic testing. However, the purpose of this provision is to mitigate the impact of 192.611 on\nexisting pipeline segments that are in satisfactory physical condition. By no means does the provision\nsuggest that such a segment is as safe as if it were constructed to Class 3 standards. Thus, we could not\nwaive 192.243(d)(3) on the basis of this provision of 192.611 and be sure the waiver would not\ncompromise safety.\nSecond, the petition requests waiver of 192.243(f) to avoid recording the total number of girth welds and\nthe precise location of each girth weld on portions of the system where Part 192 requires nondestructive\ntesting. The petition suggests that LFC Pipeline Corporation could construct a record of the total\nnumber of girth welds by estimating the number.\nIf such a record were constructed properly, we would consider it in compliance with the provision of\n192.243(f) regarding the number of girth welds made. Also, 192.243(f) does not require operators to\nrecord the precise location of girth welds. Thus, this requested waiver of 192.243(f) is unnecessary.\nFinally, the petition requests waiver of 192.243(d)(3) and (f) for portions of the system that LFC Pipeline\nCorporation believes are now outside the jurisdiction of Part 192, but may come under Part 192 because\nof land development or change in operation from rural gathering to transmission. Under Section 3(a) of\nthe NGPSA (49 App. U.S.C. 1672(a)), standards affecting construction (such as the welding standards in\npart 192) do not apply to pipelines existing when the standards are adopted. Because of this provision of\nthe NGPSA, the welding standards in Part 192 do not apply to girth welds existing in rural gas gathering\nlines that come under the jurisdiction of part 192 after they are put into operation. Thus, this requested\nwaiver of 192.243(d)(3) and (f) is unnecessary.\nThe petition refers to the subject pipeline system as a gathering system. Our review of the petition,\nhowever, suggests that portions of the system may be transmission. Correctly classifying a pipeline as\ngathering or transmission involves several considerations and affects whether part 192 applies to the\npipeline. We suggest, therefore, that LFC Pipeline Corporation discuss this matter with the Chief of our\nWestern Region office. That office is responsible for inspecting gas pipelines in California that do not\ncome under the jurisdiction of the California Public Utilities Commission. The Western Region address is\n555 Zang Street, Lakewood, Colorado 80228; phone 303-236-3424.\n91-10-22.doc 192.243, 192.611\n\n<<<PAGE 3>>>\n\nIf you have any recent additional information that bears on the above decisions, please let us know. will gladly reconsider the petition.\nWe\nSincerely,\nGeorge W. Tenley, Jr.\nAssociate Administrator for\nPipeline Safety\n91-10-22.doc 192.243, 192.611","truncated":false,"body_characters":7371}