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Safety Recommendation Details

Safety Recommendation P-77-027
Details
Synopsis: 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.
Recommendation: TAKE NECESSARY STEPS TO INSURE THAT STUDS ON COMPRESSORS COMPONENTS ARE TIGHTENED TO THE NUMBER OF FOOT-POUNDS OF TORQUE RECOMMENDED BY THE EQUIPMENT MANUFACTURER.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Pipeline
Location: Robstown, TX, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA77MP005
Accident Reports:
Exxon Gas System, Inc., Natural Gas Explosion and Fire
Report #: PAR-77-03
Accident Date: 12/7/1976
Issue Date: 10/31/1977
Date Closed: 11/21/1978
Addressee(s) and Addressee Status: ExxonMobil Corporation (Closed--No Longer Applicable)
Keyword(s):

Safety Recommendation History
From: NTSB
To: ExxonMobil Corporation
Date: 8/19/1981
Response:

From: ExxonMobil Corporation
To: NTSB
Date: 6/29/1981
Response: EXXON GAS SYSTEM, INC. LTR: WE PLAN TO EXTEND THE PERIOD OF TORQUE VERIFICATION FROM 4500 OPERATING HOURS TO 9000 OPERATING HOURS BASED ON EXPERIENCED GAINED FROM 20 TORQUE VERIFICATIONS PERFORMED SINCE EARLY 1978. DATA COLLECTED TO DATE SHOWS THAT THE TORQUE VERIFICATION PERIOD CAN BE EXTENDED AND STILL MAINTAIN OUR PRESENT LEVEL OF PERSONNEL AND EQUIPMENT SAFETY.

From: NTSB
To: ExxonMobil Corporation
Date: 1/5/1979
Response:

From: ExxonMobil Corporation
To: NTSB
Date: 12/20/1977
Response: LTR FROM EXXON GAS SYSTEM: EXXON HAS IMPLEMENTED PROCEDURES USING CALIBRATED TORQUE WRENCHES. TORQUES ARE RECHECKED EACH TIME THEY ARE DISTURBED DURING MAINTENANCE. ALL VALVE COVER STUDS HAVE BEEN CHECKED PLUS A NUMBER OF OTHER CRITICAL BOLTS. EXXON PLANS TO COMPLETE A CHECK OF ALL CRITICAL STUDS BY MARCH 15, 1978. ULTRASONIC TESTING OF SOME BOLTS AND STUDS HAS BEEN PERFORMED BUT NOT UNDER A FORMAL SCHEDULE.