SUNOCO PIPELINE L.P.

Incident Narrative

ON 3/2/19 AT APPROXIMATELY 16:45 THE CONTROL CENTER HAD INITIATED PROVING OF THE INBOUND DELAWARE BASIN METER AT THE PERMIAN EXPRESS TERMINAL. THE PROVING WAS ABORTED BY THE CONTROLLER. AFTER THE ABORT COMMAND WAS SENT THE SECTION OF PIPING BETWEEN THE METER AND RECEIPT TRAP EXPERIENCED AN OVERPRESSURE NOTED IN SCADA. CONTROLLER IMMEDIATELY SHUTDOWN THE INBOUND FLOW AND OPERATIONS PERSONNEL WERE CONTACTED AND DISPATCHED TO INVESTIGATE. AT APPROXIMATELY 17:00 LOCAL OPERATIONS PERSONNEL IDENTIFIED A SMALL RELEASE AT THE STRAINER BETWEEN THE RECEIPT TRAP AND METER. THE OVERPRESSURE CAUSED THE O-RING ON THE STRAINER TO FAIL AND LEAK. THE STRAINER O-RING WAS REPLACED, ALL OTHER ASSOCIATED PIPING VISUALLY INSPECTED AND A STATIC PRESSURE TEST COMPLETED ON THE AFFECTED PIPING AND APPURTENANCES TO ENSURE NO OTHER DAMAGE HAD BEEN INCURRED. REVIEW OF THE INCIDENT IDENTIFIED THAT AFTER THE PROVING WAS ABORTED THE AUTOMATIC VALVE SEQUENCING DID NOT PROPERLY OCCUR ALLOWING PROVER VALVES TO CLOSE PRIOR TO THE BYPASS VALVE OPENING RESULTING IN THE OVERPRESSURE. THE PROVER AND AFFECTED METER REMAINED LOCKED OUT WHILE PROGRAMMING LOGIC REVIEW AND ADDITIONAL INVESTIGATION TOOK PLACE. THE INBOUND FLOW WAS RESTARTED THROUGH AN ALTERNATE RECEIPT METER AT 20:45 UNDER MANNED OBSERVATION. FURTHER INVESTIGATION DETERMINED THAT THE BYPASS VALVE HAD LOOSE WIRING WHICH CAUSED THE VALVE TO STALL IN CLOSED POSITION WHEN METER PROVING WAS ABORTED ON 3/2/19. IT IS BELIEVED THAT THE LOOSE WIRING WAS CAUSED BY VIBRATION OVER TIME. THE TRAVEL LIMIT SWITCHES ON THE BYPASS VALVE WERE FOUND TO BE IMPROPERLY SET CAUSING THE VALVE TO NOT TRAVEL TO FULL OPEN POSITION WHICH CAUSED VIBRATION DURING CERTAIN LEVELS OF FLOW. THE LOOSE WIRING WAS REPAIRED, THE VALVE TRAVEL LIMIT SWITCHES WERE ADJUSTED AND THE PROGRAMMING LOGIC FOR PROVER OPERATION VALVE SEQUENCING WAS REVIEWED AND TESTED WITH ALL FOUND TO BE CORRECT. METER SET WAS RETURNED TO NORMAL OPERATION.