NTSB Safety Recommendation P-83-032

NTSB safety recommendation P-83-032.

THE NTSB RECOMMENDS THAT THE EL PASO NATURAL GAS COMPANY: INCLUDE IN ITS MAINTENANCE AND OPERATIONS MANUAL TORQUING SPECIFICATIONS FOR MACHINERY IN CRITICAL SERVICE AS WELL AS THE CORRECT SEQUENCE OF BOLT TIGHTENING AND PROHIBIT THE PRACTICE OF TIGHTENING BOLTS UNDER PRESSURE.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1984-01-17

Adopted Date: 1983-12-12

Overall Date Closed: 1984-07-05

Synopsis: ON MAY 26, 1983, NATURAL GAS AT 815 POUNDS/SQUARE INCH GAGE (PSIG) BEGAN TO ESCAPE THROUGH A FAILED GASKET IN A COMPRESSOR AT THE EL PASO NATURAL GAS COMPANY'S BLANCO GASOLINE PLANT NEAR BLOOMFIELD, NEW MEXICO. THE COMPRESSOR STATION OPERATOR HEARD A LOUD NOISE, RAN TO THE VALVE MANIFOLD OUTSIDE THE COMPRESSOR BUILDING, AND TRIED TO SHUT OFF THE GAS SUPPLY TO COMPRESSOR NO. 14. ANOTHER EMPLOYEE, WHO ALSO HEARD THE NOISE, RAN INTO THE COMPRESSOR BUILDING AND TRIED TO SHUT DOWN THE COMPRESSOR ENGINE. BEFORE EITHER PERSON SUCCEEDED, THE ESCAPING GAS IGNITED, EXPLODED, AND BURNED. THE TWO EMPLOYEES WERE BURNED SEVERELY, ONE COMPRESSOR WAS DESTROYED, ANOTHER COMPRESSOR WAS DAMAGED, THE WINDOWS AND DOORS OF THE COMPRESSOR BUILDING WERE BLOWN OUT, AND OTHER STRUCTURAL DAMAGE RESULTED.

Probable Cause: The probable cause was the improper tightening of compressor head bolts, which caused a compressor head gasket to rupture and release natural gas that ignited; contributing factors were El Paso’s lack of proper bolt-tightening procedures and maintenance training, and inadequate emergency-procedure training that delayed blowdown and extended the emergency.

Ntsbnumber: DCA83MP019

Report Number: PAR-83-04

Addressee Name: El Paso Natural Gas Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1984-07-05

Addressee Acronym: EPNG

Addressee Organization Type: P-Private Industry

Communication Date: 1984-03-02

Communication Type: Official Correspondence

Communication Contents: EL PASO NATURAL GAS COMPANY LETTER: ALL PLANTS THAT OPERATE RECIPROCATING COMPRESSORS WILL INCORPORATE IN THEIR MAINTENANCE AND OPERATIONS MANUAL APPROPRIATE TORQUING SPECIFICATIONS FOR EACH COMPRESSOR IN CRITICAL SERVICE.

Addressee Acronym: EPNG

Addressee Organization Type: P-Private Industry

Communication Date: 1984-07-05

Communication Type: Official Correspondence