ENABLE GAS TRANSMISSION, LLC

Incident Narrative

ON 3/6/2019 AT 06:50 ENABLE GAS TRANSMISSION SYSTEM CONTROL NOTICED A DECREASE IN FLOW FOR LINE S AND DISPATCHED THE LOCAL OPERATIONS GROUP TO INVESTIGATE. UPON ARRIVING AT THE TAYLOR COMPRESSOR STATION, OPERATIONS DISCOVERED GAS BLOWING THROUGH THE UNIT 4 BLOWDOWN STACK. AFTER FURTHER INVESTIGATION, OPERATIONS DISCOVERED A DISCHARGE VALVE HAD OPENED CAUSING GAS FROM LINE S TO FILL THE STATION AND GAS WAS VENTING TO ATMOSPHERE THROUGH AN OPEN BLOWDOWN. USING GAS PRESSURE TO SHUT THE DISCHARGE VALVE, THE STATION WAS ISOLATED FROM LINE S. OPERATIONS WORKED WITH SYSTEM CONTROL TO CONFIRM THAT PRESSURE ON LINE S HAD INDEED STARTED TO BUILD. FURTHER INVESTIGATION DETERMINED THE DISCHARGE VALVE OPENED DUE TO HYDRAULIC PRESSURE LEAKING BACK THROUGH TO THE MANUAL HAND PUMP BY WAY OF A CUT O-RING. THIS ALLOWED GAS TO FLOW INTO THE STATION AND SINCE THE STATION BLOWDOWNS WERE OPEN (TO ELIMINATE ANY BUILDUP OF STATION GAS THAT MIGHT LEAK BY CLOSED VALVES WHILE THE STATION IS OFFLINE) GAS WAS ALLOWED TO VENT TO ATMOSPHERE. A PUMP OVERHAUL KIT WAS PURCHASED AND INSTALLED ON THE FAULTY MANUAL HAND PUMP. AFTER THE OVERHAUL KIT WAS INSTALLED AND TESTED IT WAS NOTICED THAT THE MACHINING INSIDE THE MANUAL HAND PUMP HAD AN ILL-MACHINED PORT THAT WAS CUTTING THE NEW O-RING SIMILAR TO THE FIRST O-RING. A NEW PUMP WAS INSTALLED. THE GAS LOSS WAS DETERMINED TO BE 8.6 MMCF AT 14:17 AND A CALL WAS PLACED TO THE NRC (#1239400) AT 14:28. A 48-HOUR FOLLOW UP WAS PROVIDED TO THE NRC (#1239553) ON 3/8/19 AT 07:47