WEST TEXAS GULF PIPELINE CO

Incident Narrative

AT 22:56 ON JUNE 19 CONTROL CENTER RECEIVED LEL ALARM AT WORTHAM WHICH CAUSED A STATION LOCKOUT. CONTROLLER CALLED AREA SUPERVISOR TO HAVE PERSONNEL DISPATCHED TO THE STATION TO INVESTIGATE. AT 23:01 CONTROLLER BEGAN TO SHUT DOWN THE SYSTEM. LOCAL OPERATING PERSONNEL ARRIVED TO THE STATION AT 23:54 AND FOUND AND CONFIRMED THE RELEASE AT 00:08 ON JUNE 20. THE IMMEDIATE APPARENT CAUSE OF THE RELEASE WAS A GASKET FAILURE ON AN ANSI 600 SERIES FLANGED, 2"" BRANCH DRAIN CONNECTION TO THE 10"" RELIEF LINE OFF OF THE INBOUND 26"" MAINLINE. THIS SHORT BRANCH DRAIN CONNECTION SUPPORTED A CANTILEVERED BALL VALVE. ALL PRODUCT RELEASED WAS CONTAINED ON COMPANY PROPERTY PRIMARILY IN TWO (2) RETENTION PONDS INSIDE THE STATION. CONTAMINATED EQUIPMENT WAS CLEANED, CONTAMINATED SOIL WAS REMOVED AND ALL FREE PRODUCT SKIMMED FROM RETENTION PONDS. FAILURE ANALYSIS REVEALED THAT THE MOST LIKELY CAUSE OF THE FAILURE WAS VIBRATIONAL SELF-LOOSENING OF THE FLANGE STUDS OF THE 2"" BRANCH DRAIN CONNECTION AND THE STUDS HOLDING THE VALVE BODY TOGETHER WHICH RESULTED IN GASKET FAILURES AT EACH POINT. THE ASSOCIATED 10"" RELIEF LINE PIPING THAT CONTAINED THE 2"" BRANCH DRAIN CONNECTION WAS REMOVED AND REPLACED IN NOVEMBER 2015 WITH A SPOOL PIECE THAT DOES NOT CONTAIN A SIMILAR BRANCH CONNECTION TO PREVENT ANY FUTURE RECURRENCE.