ONEOK NGL PIPELINE, LLC

Incident Narrative

LOCAL AREA OPERATIONS REP RECEIVED A CALL FROM A LANDOWNER STATING THAT A SMALL WHITE VAPOR CLOUD HAD BEEN OBSERVED AT THE CAPITAL PUMP STATION INSIDE THE FENCE LINE. WHILE THE AREA REP WAS ENROUTE TO THE SITE HE CONTACTED THE CONTROLLER TO INFORM HIM ABOUT THE RELEASE. THE CONTROLLER INFORMED THE REP THAT THERE WAS NO PRESSURE LOSS AT THE FACILITY AND NO RELEASE HAD BEEN DETECTED. WHEN THE AREA REP ARRIVED ON SITE HE FOUND A SMALL VAPOR CLOUD AT THE PIG LAUNCHER. AFTER DEPRESSURIZING THE LAUNCHER THE REP OPENED THE CLOSURE DOOR AND THE O-RING CAME APART. UPDATED WITH INVESTIGATION RESULTS 6/07/2017 N JONES CAUSE MAP NARRATIVE ' LAUNCHER O-RING FAILURE PROBLEM: PRODUCT RELEASE COMING FROM LAUNCHER ENCLOSURE DOOR AND VAPOR CLOUD OBSERVED BY LANDOWNER WITHIN THE FENCE PERIMETER OF CAPITAL PUMP STATION. AREA OF CONCERN: DAMAGED O-RING'WHY WAS IT DAMAGED? A. WAS THE O-RING INSTALLED CORRECTLY? 1. THE TEAM INTERVIEWED THE AREA REP ABOUT THE O-RING INSTALLATION PROCEDURE BEING UTILIZED AND DETERMINED THAT THE O-RING WAS INSTALLED CORRECTLY. IT WAS ALSO DETERMINED THAT REMOVAL AND INSPECTION OF THE O-RING EACH TIME THE CLOSURE DOOR IS UTILIZED IS IMPERATIVE AS WELL'INSPECTING THE ENTIRE O-RING FOR CUTS, BLISTERS, CRACKS, FLAT SPOTS, ETC' B. WAS THE PROPER TORQUE APPLIED WHEN CLOSING THE ENCLOSURE DOOR? 1. PROCEDURE WAS REVIEWED WITH THE REP AND IT WAS DETERMINED THAT THE APPROPRIATE METHOD WAS USED TO APPLY APPROPRIATE AMOUNT OF TORQUE. SOLUTION: ENSURE TIGHTENING/TORQUE PROCEDURES ARE COMPLIANT WITH MANUFACTURERS RECOMMENDED GUIDELINES. USE OF SPANNING WRENCH OR CAT TOOL IS HIGHLY RECOMMENDED. C. DID THE GREASE CURRENTLY BEING APPLIED TO THE O-RING HAVE ANY EFFECT ON OR LEAD TO ANY OF THE DAMAGE ON THE O-RING? 1. CONTACTED THE MANUFACTURER OF THE LUBE GREASE BEING USED (NAPA LUBRIPLATE #105 MOTOR ASSEMBLY GREASE). AFTER SPEAKING WITH THE PRODUCT TECHNICIAN AND DESCRIBING TO HIM OUR PROCESS, PRODUCTS AND UNDER WHAT CONDITIONS WE WERE APPLYING THE GREASE HE SUGGESTED THAT WE DISCONTINUE USING THIS PRODUCT. HE SAID THAT THE MATERIAL IS BEST USED ON INTERNAL MACHINERY PARTS WHERE TEMPERATURES RANGE IN EXCESS OF 20 DEGREES. HE WENT ON TO SAY THAT THERE WAS THE SLIGHT POSSIBILITY THAT WHEN THE COOLER TEMPERATURE OF OUR PRODUCT CAME IN CONTACT WITH A LARGER AMOUNT OF THE LUBE CONCENTRATED IN ONE AREA THAT IT COULD HAVE HARDENED AND STUCK TO THE ENCLOSURE DOOR. WHEN THE CLOSURE DOOR WAS OPENED IT COULD HAVE REMOVED A PORTION OF THE GASKET WITH IT...POSSIBLY RESULTING IN THE EROSION SPOTS AND SECTIONS BEING REMOVED FROM THE O-RING. SOLUTION: IT WAS RECOMMENDED TO USE A PRODUCT CALLED 'LOC-CEASE'. D. UNDERSTAND 'EXPLOSIVE DECOMPRESSION' AND INCREASING DECOMPRESSION TIME 1. EXPLOSIVE DECOMPRESSION OR GAS EXPANSION RUPTURE IS CAUSED BY HIGH PRESSURE GAS TRAPPED WITHIN THE INTERNAL STRUCTURE OF THE SEAL ELEMENT. RAPID DECREASE IN SYSTEM PRESSURE CAUSES THE TRAPPED GAS TO EXPAND TO MATCH THE EXTERNAL PRESSURE AND THIS CAUSES BLISTERS AND RUPTURES ON THE SEAL SURFACE. IF THE VOLUME OF TRAPPED GAS IS SMALL, THE BLISTERS MAY RECEDE AS THE PRESSURE IS EQUALIZED WITH LITTLE EFFECT ON SEAL INTEGRITY. EXCESSIVE TRAPPED GAS MAY CAUSE TOTAL DESTRUCTION OF THE SEAL. SOLUTION: INCREASE DECOMPRESSION TIME TO ALLOW TRAPPED GAS TO WORK OUT OF SEAL MATERIAL. CHOOSE A SEAL MATERIAL WITH GOOD RESISTANCE TO EXPLOSIVE DECOMPRESSION. E. IS THE CORRECT O-RING MATERIAL BEING UTILIZED? 1. THE O-RING WAS SENT TO A LAB TO BE ANALYZED BY OUR MECHANICAL INTEGRITY GROUP BUT THE LAB WAS UNABLE TO TEST THIS PARTICULAR PRODUCT. SOLUTION: USE THE O-RING MATERIAL KNOWN AS FKM (VITON). FKM (VITON) IS A HIGHER GRADE MATERIAL THAT HAS BEEN DESIGNED TO ADDRESS THE SPECIFIC REQUIREMENTS OF HIGH PRESSURE, LOW TEMPERATURE GAS/LIQUID APPLICATIONS AND IS RESISTANT TO EXPLOSIVE DECOMPRESSION.