{"operation":"document","citation":"P-77-032","title":"NTSB Safety Recommendation P-77-032","source_type":"guidance","agency":"National Transportation Safety Board","status":"guidance","official":true,"published_on":"1977-10-31","effective_on":"1977-10-31","summary":"DESIGNATE CRITICAL VALVES ON CONTROL LINES (GAS, AIR, AND HYDRAULIC) AS TO WHETHER THEY SHOULD BE NORMALLY OPEN OR CLOSED, AND PLACE SIGNS ON THESE VALVES WHENEVER THE LINES ARE SHUT DOWN FOR MAINTENANCE OR WHEN THE VALVES ARE NOT IN THEIR NORMAL POSITIONS. SUCH CHANGES SHOULD BE AUTHORIZED, LOGGED, AND REPORTED TO ALL PERSONNEL RESPONSIBLE FOR THE OPERATION OF THE SYSTEM.","machine_formats":{"json":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-77-032.json","markdown":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-77-032.md"},"app_url":"https://regulus.evalyn.ai/document/ntsb-recommendation-p-77-032","source_url":"https://data.ntsb.gov/carol-main-public/sr-details/P-77-032","body":"NTSB safety recommendation P-77-032.\n\nDESIGNATE CRITICAL VALVES ON CONTROL LINES (GAS, AIR, AND HYDRAULIC) AS TO WHETHER THEY SHOULD BE NORMALLY OPEN OR CLOSED, AND PLACE SIGNS ON THESE VALVES WHENEVER THE LINES ARE SHUT DOWN FOR MAINTENANCE OR WHEN THE VALVES ARE NOT IN THEIR NORMAL POSITIONS. SUCH CHANGES SHOULD BE AUTHORIZED, LOGGED, AND REPORTED TO ALL PERSONNEL RESPONSIBLE FOR THE OPERATION OF THE SYSTEM.\n\nPriority: CLASS II\n\nOverall Status: Closed - Acceptable Action\n\nIssued Date: 1977-10-31\n\nAdopted Date: 1977-10-13\n\nOverall Date Closed: 1978-09-28\n\nSynopsis: ON DECEMBER 7, 1976, A NATURAL GAS COMPRESSOR FAILED AND THEN EXPLODED AND BURNED AT AN EXXON GAS SYSTEM, INC., STATION NEAR ROBSTOWN, TEXAS. AN EMERGENCY SHUTDOWN SYSTEM WAS ACTIVATED, BUT FOUR AUTOMATED FIRE GATE VALVES DID NOT CLOSE. ANOTHER EMERGENCY CONTROL SYSTEM ALSO FAILED TO AUTOMATICALLY CLOSE THE SHUTOFF VALVES, LEADING TO TWO OF THE FIVE COMPRESSORS IN THE STATION. A SECOND EXPLOSION OCCURRED WITHIN THE BURNING BUILDING. THE FIRE KILLED ONE PERSON, INJURED TWO PERSONS, AND DESTROYED THREE ENGINE-DRIVEN COMPRESSORS AND THE COMPRESSOR BUILDING.\n\nNtsbnumber: DCA77MP005\n\nReport Number: PAR-77-03\n\nAddressee Name: ExxonMobil Corporation\n\nAddressee Status: Closed--No Longer Applicable\n\nAddressee Date Closed: 1978-09-28\n\nAddressee Organization Type: P-Private Industry\n\nCommunication Date: 1977-12-20\n\nCommunication Type: Official Correspondence\n\nCommunication Contents: EXXON GAS SYSTEM LTR: EXXON STATES THAT THIS RECOMMENDATION WILL BE IMPLEMENTED WITHIN 90 TO 180 DAYS. THE CRITICAL VALVES WILL BE COLOR-CODED TO INDICATE NORMAL POSITION AND CARSEALED IN THAT POSITION EXCEPT WHEN REQUIRED IN AN ABNORMAL POSITION IN WHICH CASE THEY WILL BE TAGGED AND LOGGED. 5/12/78 - EXXON RESPONSE TO NTSB LETTER OF 4-27-78: A PROCEDURE OF LOGGING, TAGGING, AND CARSEALING CRITICAL VALVES ON GAS, AIR, AND HYDRAULIC CONTROL LINES WAS IMPLEMENTED AS AN INTEGRAL PART OF EXXON OPERATIONS AT ALL COMPRESSOR STATIONS PRIOR TO 4-28-78. EXXON ALSO CONSIDERED IT DESIRABLE TO COLOR-CODE DESIGNATED CONTROL LINE VALVES TO INDICATE THEIR NORMAL POSITION. THIS HAS ALSO BEEN COMPLETED.\n\nAddressee Organization Type: P-Private Industry\n\nCommunication Date: 1979-01-05\n\nCommunication Type: Official Correspondence","truncated":false,"body_characters":2279}