{"operation":"document","citation":"P-92-021","title":"NTSB Safety Recommendation P-92-021","source_type":"guidance","agency":"National Transportation Safety Board","status":"guidance","official":true,"published_on":"1992-07-08","effective_on":"1992-07-08","summary":"THE NTSB RECOMMENDS THAT THE CONSUMERS POWER COMPANY: IMPLEMENT PROCDURES, SUCH AS THE ELIMINATION OR THE REDUCTION OF THE PIPELINE PRESSURE TO A SAFE LEVEL, TO PREVENT THE UNINTENDED SEPARATION OF PIPELINE SEGMENTS FROM KNOWN OR UNKNOWN NEARBY UNANCHORED COMPRESSION COUPLINGS WHEN PIPE IS EXCAVATED OR REMOVED.","machine_formats":{"json":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-92-021.json","markdown":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-92-021.md"},"app_url":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-92-021","source_url":"https://data.ntsb.gov/carol-main-public/sr-details/P-92-021","body":"NTSB safety recommendation P-92-021.\n\nTHE NTSB RECOMMENDS THAT THE CONSUMERS POWER COMPANY: IMPLEMENT PROCDURES, SUCH AS THE ELIMINATION OR THE REDUCTION OF THE PIPELINE PRESSURE TO A SAFE LEVEL, TO PREVENT THE UNINTENDED SEPARATION OF PIPELINE SEGMENTS FROM KNOWN OR UNKNOWN NEARBY UNANCHORED COMPRESSION COUPLINGS WHEN PIPE IS EXCAVATED OR REMOVED.\n\nPriority: CLASS II\n\nOverall Status: Closed - Acceptable Action\n\nIssued Date: 1992-07-08\n\nAdopted Date: 1992-06-19\n\nOverall Date Closed: 1992-12-08\n\nSynopsis: ABOUT 12:00 NOON EASTERN DAYLIGHT SAVINGS TIME ON JULY 17, 1991, WORKERS WERE REMOVING A CORRODE SEGMENT OF THE CONSUMERS POWER COMPANY'S (CP) 10-INCH-DIAMETER TRANSMISSION LINE PIPELINE AT BAILEY BRIDGE ROAD IN MAPLETON, MICHIGAN. AS A SEGMENT OF THE PIPELINE WAS BEING REMOVED, NATURAL GAS AT 360-PSIG PRESSURE EXERTED ABOUT 12 TONS OF FORCE ON AN ADJACENT CLOSED VALVE (H-143) CAUSING IT AND A SHORT SEGMENT OF CONNECTED PIPE TO MOVE AND SEPARATE FROM AN UNANCHORED COMPRESSION COUPLING. THE FORCE OF THE ESCAPING GAS KILLED ON WORKER (A WELDER), INJURED FIVE OTHER WORKERS, AND COLLAPSED A STEEL PIT THAT HOUSED VALVE H-143.\n\nProbable Cause: None\n\nNtsbnumber: DCA91FP010\n\nReport Number: None\n\nAddressee Name: Consumers Power Company\n\nAddressee Status: Closed - Acceptable Action\n\nAddressee Date Closed: 1992-12-08\n\nAddressee Acronym: CMS\n\nAddressee Organization Type: P-Private Industry\n\nCommunication Date: 1992-12-08\n\nCommunication Type: Official Correspondence\n\nCommunication Contents: THE BOARD UNDERSTANDS THAT THE CP HAS EXPANDED ITS WRITTEN PROCEDURE TO INCLUDE THE REPLACEMENT OF HIGH-PRESSURE MAIN & 4-INCH & LARGER MEDIUM-PRESSURE MAINS THAT MAY CONTAIN COMPRESSION COUPLINGS, AS WELL AS THE EVALUATION OF LOWERING THE SYSTEM OPERATING PRESSURE, WHERE FEASIBLE. THE CP HAS ALSO DEVELOPED NEW WORK METHODS TO PREVENT WORKER INJURY SHOULD A PULLOUT OCCUR WHEN REPLACING MAIN THAT MAY CONTAIN COMPRESSION COUPLINGS. BASED ON THIS INFORMATION, RECOMMENDATION P-92-21 HAS BEEN CLASSIFIED AS \"CLOSED--ACCEPTABLE ACTION.\"\n\nAddressee Acronym: CMS\n\nAddressee Organization Type: P-Private Industry\n\nCommunication Date: 1992-09-25\n\nCommunication Type: Official Correspondence","truncated":false,"body_characters":2188}