EL PASO NATURAL GAS CO — Gas transmission and gathering — incident on 2016-10-14

Gas transmission and gathering incident in Not Within a Municipality, COCHISE COUNTY County, AZ. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 8490 NATURAL GAS released, $500 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20160090.

Operator ID: 4280.

Reported incident date: 10/14/2016 13:17.

Location detail: MP 226+1584

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON 10-14-2016 AT APPROXIMATELY 1:17 PM MST A KINDER MORGAN TECHNICIAN WAS NOTIFIED BY A SOUTHWEST GAS (SWG) TECHNICIAN THAT HE THOUGHT THE EPNG RELIEF VALVE LOCATED AT VALVE 31 NEAR MONUMENT 90 METER STATION WAS VENTING. UPON INVESTIGATION, IT WAS DETERMINED THAT THE PRIMARY REGULATOR ON LINE 2003 NEAR VALVE 31 FAILED TO COMPLETELY CLOSE CAUSING THE DOWNSTREAM PRESSURE TO RISE ABOVE THE RELIEF VALVE SET-POINT OF 550 PSIG. THE RELIEF VALVE ACTUATED AND REDUCED THE LINE PRESSURE AS INTENDED AVOIDING PRESSURES EXCEEDING THE ESTABLISHED MAOP OF DOWNSTREAM FACILITIES, HOWEVER THE RELIEF VALVE FAILED TO CLOSE WHEN THE LINE PRESSURE REACHED THE RELIEF VALVE RESET PRESSURE DUE TO A FAILED INTERNAL SEATING COMPONENT AND RESULTED IN THE RELEASE OF APPROXIMATELY 8.49 MMSCF OF NATURAL GAS. THE AFFECTED REGULATOR AND RELIEF VALVE WERE REPAIRED FOLLOWING THE INCIDENT AND RETURNED TO SERVICE.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $25,970 reported total cost, $27,366.427 in 1984 dollars, $33,909.01 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.