COLUMBIA GAS TRANSMISSION CORP — Gas transmission and gathering — incident on 2011-12-08

Gas transmission and gathering incident in RIPLEY, JACKSON County, WV. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 16424 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: 20120004.

Operator ID: 2616.

Reported incident date: 12/8/2011 4:45.

Location detail: COMPRESSOR ST

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: A SHUTTLE VALVE HAD FAILED CAUSING AN UNINTENDED RELEASE OF NATURAL GAS TO VENT INTO ATMOSPHERE VIA AN 8-IN BLOW-OUT PIPE. THE COMPRESSOR STATION WAS SHUT DOWN TO STOP THE FLOW OF NATURAL GAS INTO ATMOSPHERE AND TO SECURE THE SITE FOR FURTHER INVESTIGATIONS. AN INVESTIGATIVE TEAM WAS LAUNCHED TO LOOK INTO THE PROBABLE CAUSE OF THIS INCIDENT. THE MANUFACTURER IS ASSISTING THE COMPANY ENGINEERING TEAM IN LOOKING INTO THE ROOT CAUSE OF THIS SHUTTLE VALVE FAILURE. ADDITIONAL INFORMATION WILL BE SUBMITTED IN THE FINAL INCIDENT REPORT. SUPPLEMENT/FINAL REPORT (SUBMITTED ON 02/28/2018 BY CHRIS LEGG) AN ONSITE INVESTIGATION WAS CONDUCTED ON 12/08/2011 FOLLOWING THE INCIDENT. THE ESD PILOT AIR POPPET VALVE, WHICH TRIGGERS THE ESD BLOWDOWN VALVE (8"), SOMETIMES REFERRED TO A "SHUTTLE VALVE", FAILED AFTER IT WAS STUCK IN THE OPEN POSITION. ED CLARKSON, WV PSC WAS ON-SITE DURING THE INVESTIGATION. DURING THE INVESTIGATION, SEVERAL SMALL LEAKS WERE LOCATED AROUND TUBING FITTINGS IN THE PILOT AIRLINE. POSSIBLE THAT PILOT LINE VENTED BETWEEN A FREEZE POINT AND THE TUBING LEAKS, WHICH THEN ALLOWED THE ACTUATOR TO GO OPEN. THE PILOT AIRLINE WAS DISASSEMBLED, BUT NO OBVIOUS SIGNS OF A FREEZE OR OTHER BLOCKAGE WAS SEEN. THE OTHER POSSIBILITY WAS THAT LIQUIDS IN THE POWER GAS FROZE INSIDE THE POPPET VALVE ASSEMBLY AND FORCED THE POPPET VALVE OPEN, WHICH THEN CAUSED THE ACTUATOR TO GO OPEN. AS A RESPONSE TO THE FAILURE, THE ESD PILOT AIR POPPET VALVE ON THE ACTUATOR WAS REBUILT AND FURTHER INSPECTED ON 12/13/2011 (MAXIMO WORK ORDER#: B2568587). AS A PREVENTATIVE MEASURE, ALL OF THE OTHER ESD PILOT AIR POPPET VALVES AT THE STATION WERE ALSO LATER REBUILD.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $56,006 reported total cost, $39,293.73 in 1984 dollars, $48,246.732 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.