{"operation":"document","citation":"PI-77-019","title":"Memo: Internal — Pipeline Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1977-07-27","effective_on":null,"summary":"PI-77-019 response to Memo: Internal concerning 192.755.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-019.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-019.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-77-019","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1977/PI77019.pdf","body":"<<<PAGE 1>>>\n\nChief, Eastern Region, MTP-50-EA\nActing Director, Office of Pipeline\nSafety Operations\nAlternatives to Section 192.755\nYour memorandum of March 21, 1977, on this subject asks two separate but related questions\nabout possible methods of compliance with Section 192.755, \"Protecting cast-iron pipelines.\"\nThis section is applicable where an existing buried pipeline is crossed by an earth excavation or\nditch or is located in potentially unstable soil due to an excavation being dug nearby and deeper\nthan the gas pipeline.\nSection 192.755 requires When an operator has knowledge that the support for a segment of a\nburied cast-iron pipeline is disturbed:\n(a) That segment of the pipeline must be protected, as damage during the disturbance by:\nnecessary, against\n(1) Vibrations from heavy construction equipment, trains, trucks,\nbuses, or blasting;\n(2) Impact forces by vehicles;\n(3) Earth movement;\n(4) Apparent future excavations near the pipeline; or\n(5) Other foreseeable outside forces which may subject that segment of the\npipeline to bending stress.\n(b) As soon as feasible, appropriate steps must be taken to provide permanent\nprotection for the disturbed segment from damage that might result from external loads,\nincluding compliance with applicable requirements of Sections 192.317(a), 192.319, and\n192.361(b)-(d).\nFollowing are the questions submitted and OPSO's interpretations.\nQuestion: If an operator cuts a cast-iron pipe in two and installs a leak clamp at a point\nwhere the operator suspects soil settlement as a result of excavation by others, can this be\nconsidered as a satisfactory alternative to the requirements of Section 192.755?\ndal\\192\\755\\77-07-27\n1\n\n<<<PAGE 2>>>\n\nInterpretation: The cutting of the pipe and installation of the coupling would possibly be of some\nbenefit by providing flexibility. However, without providing other means of support, such as\ncompacting the soil to an equivalent compaction as the\n2\noriginal soil, supporting with a beam to undisturbed soil, or replacing the cast-iron pipe across the\narea with steel pipe extending well into the undisturbed soil, the segment would not be protected\nto a degree sufficient to assure the safety of the installation.\nQuestion: In the case of a leak caused by cast-iron pipe breaking in two, can the installation of a\nleak clamp suffice for the requirements of Section 192.755? Or, must the operator comply with\nthe requirements of Section 192.755 as well so as to protect the pipe segment that was excavated\nagainst possible subsequent bending stress due to soil settlement?\nInterpretation: The installation of a leak clamp would be considered as adequate leak repair but it\ndoes not provide protection against further soil settlement. As indicated above, measures must be\ntaken to stop or minimize the soil movement or some degree of resistance must be provided in the\nstructural strength of the piping system crossing the affected area of construction.\nMany operators have adopted a standard policy of replacing cast-iron pipe in this sort of a\nsituation with steel pipe and taking necessary measures to protect the steel pipe. Attached are\ncopies of a standard procedure that is used by one company for such construction areas.\nCesar DeLeon, MTP-1\nAttachment\ndal\\192\\755\\77-07-27\n2","truncated":false,"body_characters":3289}