{"operation":"document","citation":"PI-83-0101","title":"Pipeline Safety Interpretation PI-83-0101","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"1983-01-26","effective_on":null,"summary":"PI-83-0101 concerning 192.603.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-83-0101.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-83-0101.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-pi-83-0101","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/1983/g83-01-26_Paullin_192.603-msfx.pdf","body":"<<<PAGE 1>>>\n\nPI-83-0101\nJanuary 26, 1983\nRobinson/62392\nACTION: Recommendation for Establishing of Safety Standards in Part 192 and Revision of Part 195\nOriginal signed by\nRichard L. Beam\nAssociate Director for Pipeline Safety Regulation, DMT-30\nRobert L. Paullin\nAssociate Director for Operations & Enforcement, DMT-10\nYour memo dated January 3, 1983, recommended the adoption of a design standard for scraper traps in Parts\n192 and 195. We have reviewed the matter and find the following:\nLiquid Pipelines\nSection 195124 requires that closures be designed in accordance with the ASME Boiler and Pressure Vessel\nCode. Section 195.426 requires certain safety devices on scraper traps. These two sections currently require all\nof the safety provisions recommended in your memo. Further, §195.402(a) and (c)(3) are sufficiently broad to\nrequire operating procedures for scraper traps. Finally, of the 4,250 liquid pipeline accidents reported\nbetween 1968 and 1982, 19 involved scraper traps causing $56,000 in property damage, but none involved\ninjuries or fatalities. Therefore, we do not believe that further rulemaking concerning design or operation of\nscraper traps is indicated for liquid pipelines.\nGas Pipelines\nThere is no current design requirement for scraper traps in Part 192 equal to §195.124, nor is there a\nrequirement in Part 192 comparable to §195.426. However, the operating requirements of §§192.603(b) and\n192.605(a) may be applied to scraper traps. Further, the B31.8 Code does not have specific design or\noperating requirements for scraper traps. Of the 6,588 gas transmission pipeline accidents reported between\n1970 and 1982, 10 involved scraper traps resulting in 4 fatalities and 4 injuries, together with $214,000 in\nproperty damage.\nWhile one might argue that the absence of scraper trap regulations resulted in more serious scraper trap\nrelated accidents on gas transmission pipelines, we doubt that such is the case. More likely, we believe that a\ngreater hazard is presented by the gas pipeline scraper trap because gas is compressible.\nWould this greater hazard justify imposing additional scraper trap regulations on gas pipelines? We believe it\nunlikely that a design regulation similar to §195.124 can be justified for gas pipelines for two reasons: (1)\nBecause we are not authorized to impose a design regulation retroactively, a new design rule would affect\nonly new scraper traps and would leave unaffected the many in existence; and (2) Since about 1960, most\nscraper traps have incorporated the safety features of the ASME Boiler and Pressure Vessel Code.\nConsequently, for new facilities we doubt that a design requirement would result in anything other than what\nthe industry now does.\n\n<<<PAGE 2>>>\n\nAnother alternative might be a gas pipeline regulation similar to the operations regulation for liquid pipelines\ngiven in §195.426. However, if we understand the accident reports correctly, the cause of the accidents\ninvolving scraper traps is not the lack of safety features but rather the failure to follow proper operating\nprocedures. The solution to that problem, it seems to us, is a rigorous application of §§192.603(b) and\n192.605(a) to assure proper scraper trap operation. If operator plans under these rules are inadequate to\nassure safe operation of scraper traps, Section 13 of the Natural Gas Pipeline Safety Act permits you to require\nthat the plans be amended.\nIn conclusion, we do not believe a design requirement for gas transmission pipeline scraper traps can be\njustified. We believe the problem you cited is one of improper scraper trap operation and that §§192.603(b)\nand 192.605(a) can be applies to resolve the problem.\n\n<<<PAGE 3>>>\n\nU.S. Department of Transportation\nResearch and Special Programs Administration\nMemorandum\nDate: January 3, 1983\nSubject: ACTION: Recommendation for establishment of Safety Standard in Part 192 and revision of\n195.426\nFrom: Robert L. Paullin\nAssociate Director for Operations and Enforcement, DMT-10\nTo: Richard L. Beam\nAssociate Director, Office of Pipeline Regulations, DMT-30\nAs a result of on site accident investigation and a review of other accident reports relating to the\nuse of pipeline pig launchers or receivers, it is recommended that a new regulation be established\nfor' Part 192 and an existing regulation in Part 195 be revised.\nThere have been several accidents, some of them fatal, because operators have used procedures\nthat were inconsistent with company guidelines or sound operating practices in regard to launching\nand receiving scrapers or spheres. If the barrel closure cover of a launcher or receiver unit was\ndesigned so that it would be impossible to open while there is pressure in the barrel, many injuries\nand fatalities would be prevented.\nThough it is recognized that it is not possible to write regulations that will keep a person from\nnegligent operating practices or from circumventing the use of safety devices, it is expected that by\nmodifying the wording of 195.426 and adding a similar provision to Part 192 operators of pig\nlaunchers or receivers will be better protected even if prone to take shortcuts. Presently, 195.426 is\nnot worded so that the equipment design prevents pressure from remaining in the barrel of the\nlauncher or receiver when the closure cover is removed. The modification that we propose should\nresult in the elimination of pressure in the barrel before the closure cover can be removed. This\nproposal is consistent with an existing rule contained in section VIII of the ASME Boiler and\nPressure Vessel Code Part UG-35.\nIn support of this recommendation I have attached a report on a recent accident investigated by\nJose L. de la Fuente of the Southwest Region, Office of Operations and Enforcement. It is expected\nthat this accident would have been avoided if the barrel and closure cover had been installed in\naccordance with the regulation being recommended for part 192. Also attached are two Accident\nBriefs from the National Transportation Safety Board that describe accidents involving scraper\ntraps at Enid and Slapout, Oklahoma.\nWe recommend the following addition to part 192 and that 195.426 be revised to read the same:\n192. Scraper and sphere facilities.\n(a) No operator may use a launcher or receiver that is not equipped with a relief device capable\nof safely relieving pressure in the barrel before insertion or removal of scrappers or spheres.\n(b) Except for the multibolted type of closure, no operator may use a launcher or receiver with\nquick-actuating closures unless the barrel closure is equipped with a locking mechanism or\ndevice so designed that, (1) the pressure cannot be built up for launching a scraper or\nsphere unless the closure mechanism is fully engaged in its intended operating position, and\n(2) the closure mechanism cannot be disengaged for removing a scraper or sphere until\npressure in the barrel has been fully released.\n\n<<<PAGE 4>>>\n\nMemorandum\nU.S. Department of Transportation\nResearch and Special Programs Administration\nDate: May 12, 1982 Reply to Attn. of: DMT -17\nSubject: Failure of a 22\" Unibolt Closure on Southern Natural Gas Pipeline Company's Gate No. 6 Valve\nPlatform @ Mile Post 39.632 in a Marshy Area of Plaquemine Parish, Louisiana\nFrom: Jose L. de la Fuente, Staff Engineer\nTo: Robert F. Aubry, Chief, Southwest Region\nI. SYNOPSIS\nAt 9:35AM on Thursday, April 8, 1982, a 22\" pig launcher under approximately 840 psig pressure on an\noffshore valve platform exploded, killing two company employees as they were attempting to open the\nclosure. The force behind the 840 psig of pressure was of such magnitude that, after one stud bolt had\nbeen totally removed by the employees, and the other one partially removed to the point where only\nhalf the threads on the nut were holding the stud bolt, the threads stripped and the unibolt flange (nut\nmember) rotated, causing the blanking plug to swing open. The tremendous, rapid release of energy\ntore the blanking plug from the hinge arm, sheared two small bolts holding the plug to the hinge arm,\nand propelled the blanking plug with such force that it damaged a concrete support directly in front of\nit and hit and damaged a guard rail as it sailed through the air before it hit the water, where it was lost.\nThis full force caught the two men as they were working on the closure and mangled and partially\ndismembered one of them and propelled the other one approximately 450 feet in the air, severing the\nbody in two in the process.\nII. PROBABLE CAUSE\nThe probable cause of this accident was the inadvertent attempt to open the closure under\napproximately 840 psig pressure. This was evident by the fact that one eye on the unibolt flange (nut\nmember) showed no evidence of damage, indicating the stud bolt was purposely removed prior to the\nrelease of energy. The opposite eye on the unibolt flange was shiny and slightly flat on bottom,\ncoinciding with the bolt pull out and flange rotation when the nut was backed off to the point at which\nonly half the threads were holding the stud bolt. Inspection of the nut clearly showed that half the\nthreads were in good condition while the other half were completely stripped.\nIII. THE ACCIDENT\nPigging operations on the second loop, east leg, 20\" mainline had been in progress since April 6th. On\nthe morning of April 8, 1982, the pig was inserted in the 22\" launcher on the valve platform, the\nblanking plug was closed and the barrel was pressurized by opening a 6\" gas supply valve. Once the\nchamber was pressurized, the 6\" gas supply valve was closed and the 20\" mainline gate valve was\nopened to equalize the pressure. When pressure was equalized, the 6\" gas supply valve was opened,\nallowing the pressure differential to propel the pig down the pipeline.\nAfter the three-man crew felt certain they heard the pig leave the launcher and travel through the\npipeline, they gave it one more minute to make sure the pig had cleared the platform. When the\n\n<<<PAGE 5>>>\n\nminute had elapsed, two men closed the 6\" gas supply valve and the 20\" mainline gate valve to isolate\nthe launcher while their supervisor instructed them to bleed down and open the trap. The supervisor\nthen proceeded downstairs to the boat to call in the report that the pig had been launched, and he did\nnot observe whether or not an attempt was made to open the 6\" blow down valve on the pig trap. As\nthe supervisor was making notes on the back of the boat at approximately 9:35AM, he heard a \"quick\nboom\", like a short, loud explosion, up on the valve platform, and he and the boat captain proceeded\nto investigate. Upon arrival upstairs they found one mangled and partially dismembered body lying on\nthe platform deck next to the pig trap, which had blown open. They saw no trace of the other crew-\nman, and proceeded downstairs to the boat to report the accident and to look for the other body.\nAt approximately 9:46AM a company helicopter was in the air, followed by another one at 9:48AM,\nenroute to the site. The missing body (upper torso only) was located by helicopter on a small island\napproximately 450 feet S.W. of the valve platform.\nThe bodies were recovered and transported to Plaquemine Parish Hospital in Port Sulpher, Louisiana,\nby air carrier helicopter.\nAll valve positions on the platform were checked, and the platform was secured by 11:27AM.\nIV. CONCLUSIONS\nThis accident was the result of an inadvertent act committed by two experienced personnel which cost\nthem their lives.\nV. RECOMMENDATIONS\nAlthough it is recognized that human error cannot be effectively regulated, nevertheless, had a\nregulation similar to Sec. 195.426 been in effect, this tragic occurrence may not have taken place.\nTherefore, I am recommending that a regulation similar in content to Sec. 195.426 be incorporated in\nPart 192.","truncated":false,"body_characters":11808}