SUNOCO PIPELINE L.P.

Incident Narrative

WHILE STARTING UP THE EOLA-MAYSVILLE 10"" LINE AT APPROXIMATELY 05:21 ON 7/23/18 THE CONTROLLER NOTED HIGHER THAN NORMAL OPERATING PRESSURES AT THE MAYSVILLE DELIVERY LOCATION AND SHUT THE LINE DOWN AT APPROXIMATELY 05:23. THE LINE REMAINED DOWN WHILE THE CONTROLLER CONDUCTED A SHIFT CHANGE, AND THEN A CALL WAS MADE TO THE OPERATIONS SUPERVISOR AT APPROXIMATELY 06:45 ABOUT THE SITUATION. AT APPROXIMATELY 06:50, A PIPELINE TECHNICIAN DISCOVERED A PRODUCT LEAK IN THE MAYSVILLE STATION YARD AROUND THE DELIVERY METER SYSTEM. HE CALLED THE CONTROLLER TO ENSURE THE SYSTEM WOULD REMAIN SHUT DOWN AND FOUND THE LEAK COMING FROM THE VENT/WEEP HOLE ON THE BACKPRESSURE VALVE TO THE INBOUND METER. VALVES UPSTREAM AND DOWNSTREAM OF THE BACKPRESSURE VALVE WERE CLOSED TO ISOLATE. ESTIMATED RELEASE VOLUME WAS ONE BARREL AND CLEANUP ACTIVITIES WERE INITIATED. UPON FURTHER INVESTIGATION INTO THE FAILURE IT WAS DETERMINED THAT THE DIAPHRAGM OF THE BACKPRESSURE VALVE FAILED WHICH ALLOWED CRUDE OIL TO LEAK THROUGH THE VENT/WEEP HOLE. THE DIAPHRAGM WAS REPLACED. FURTHER INVESTIGATION DETERMINED THAT THE BACK PRESSURE VALVE WAS RATED TO A LOWER OPERATING PRESSURE THAN STATION MOP. A VALVE RATED TO AN APPROPRIATE PRESSURE FOR THE APPLICATION WAS ORDERED TO REPLACE THE EXISTING BACKPRESSURE VALVE. UNTIL SUCH TIME THE VALVE IS REPLACED THE STATION OPERATING PRESSURE WILL BE LIMITED TO A PRESSURE BELOW THE RATING OF THE EXISTING BACK PRESSURE VALVE TO ENSURE A REOCCURRENCE DOES NOT HAPPEN.