ENABLE OKLAHOMA INTRASTATE TRANSMISSION, LLC — Gas transmission and gathering — incident on 2015-04-20

Gas transmission and gathering incident in CLAREMORE, ROGERS County, OK. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 23147 NATURAL GAS released, $10 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: 20150064.

Operator ID: 26330.

Reported incident date: 4/20/2015 7:00.

Location detail: CLAREMORE CS

Cause detail: THREADED CONNECTION/COUPLING FAILURE

Cause detail: 4/20/2015 AT 06:39: COMPRESSION TECHNICIAN WAS CONTACTED BY GAS CONTROL IN REGARDS TO AN ODOR OF GAS IN THE AREA CLOSE TO THE CLAREMORE COMPRESSOR STATION. - 07:00: HE ARRIVED ON LOCATION AND PARKED TRUCK OUTSIDE OF GATE AND WALKED INTO THE FACILITY AND NOTICED GAS VENTING OUT OF THE SILENCER. HE THEN WENT INTO THE CONTROL ROOM TO CHECK FOR ANY VALVES OUT OF POSITION THAT WOULD BE VENTING AND FOUND NONE. HE WALKED THROUGH THE YARD TO VERIFY THE GAS WAS NOT VENTING FROM THE ESD VENT VALVES AND VERIFIED IT WAS NOT. HE WENT INTO THE COMPRESSOR BUILDING AND FOUND THAT A 1/4 INCH NPT FITTING HAD BROKEN OFF THAT WAS CONNECTED TO THE TOP OF THE RELIEF VALVE ON THE INTERSTAGE DISCHARGE PIPING ON UNIT 427 CAUSING THE VALVE TO RELIEVE GAS. A SECOND COMPANY EMPLOYEE HAD ARRIVED ON THE SCENE AND ASSISTED THE COMPRESSION TECHNICIAN. - 07:28: THE BLOCK VALVE LOCATED ON THE VENT PIPING WAS CLOSED TO STOP THE GAS FROM VENTING AND THEY WERE ABLE TO MONITOR THE INTERSTAGE PRESSURE. AFTER CLOSING THE BLOCK VALVE ON THE RELIEF VALVE VENT PIPING, THE GAS BEING VENTED OUT OF THE SILENCER WAS ISOLATED. - 08:34: SHUT DOWN UNIT 427, DEPRESSURIZED, LOCKED AND TAGGED THE UNIT OUT AND REPLACED THE 1/4 INCH NPT FITTING. - APPROXIMATELY 09:08: PUT UNIT 427 BACK INTO SERVICE AND VERIFIED THE RELIEF VALVE WAS BACK TO ITS NORMAL OPERATING STATUS AND THE THERE WAS NO LONGER GAS VENTING OUT OF THE RELIEF VALVE VENT PIPING. - AFTER REVIEWING THE HISTORICAL DATA, IT WAS FOUND THAT THE INTERSTAGE DISCHARGE PRESSURE HAD DECREASED AT APPROXIMATELY 01:40 ON 4/20/15 INDICATING THE TIME THE 1/4 INCH NPT FITTING HAD FAILED.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — THREADED CONNECTION/COUPLING FAILURE.

PHMSA indexed costs: $55,420 reported total cost, $51,212.608 in 1984 dollars, $63,135.291 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.