SOUTHERN NATURAL GAS CO — Gas transmission and gathering — incident on 2015-06-24

Gas transmission and gathering incident in HOLY TRINITY, RUSSELL County, AL. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 6805 NATURAL GAS released, $0 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: 20150099.

Operator ID: 18516.

Reported incident date: 6/24/2015 0:15.

Location detail: LINE-01 MP 27

Cause detail: OTHER EQUIPMENT FAILURE

Cause detail: THE VENT VALVE ON HOLY TRINITY COMPRESSOR STATION UNIT #2 IS CONTROLLED BY A BETTIS PNEUMATIC OPERATOR WITH AIR SUPPLY TO OPERATE. BROKEN BOLTS ON THE BRACKET HOLDING THE CONTACT HOUSING TO THE OPERATOR CAUSED THE CONTACT HOUSING TO FALL TO THE GROUND AND DAMAGE THE AIR SUPPLY LINE FOR THE PNEUMATIC OPERATOR. THE VENT VALVE IS SPRING-LOADED TO DEFAULT TO THE OPEN POSITION, AND IT'S HELD CLOSED BY THE PNEUMATIC OPERATOR. WHEN THE PNEUMATIC OPERATOR LOST AIR SUPPLY PRESSURE, DUE TO THE CONTACT HOUSING FALLING AND DAMAGING THE AIR LINE, THE VENT VALVE "FAILED OPEN". THE BOLTS HAVE BEEN REPLACED AND THE BRACKET HAS BEEN REPAIRED. OPERATIONS IS WORKING WITH A MACHINE SHOP TO BUILD A STRONGER BRACKET AND A PIPE SUPPORT TO STABILIZE THE OPERATOR. THESE PIECES WILL BE INSTALLED ON BOTH UNITS AT HOLY TRINITY COMPRESSOR STATION IN AN EFFORT TO PREVENT THIS INCIDENT FROM REOCCURRING.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — OTHER EQUIPMENT FAILURE.

PHMSA indexed costs: $8,837 reported total cost, $8,170.526 in 1984 dollars, $10,066.236 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.