COLONIAL PIPELINE CO

Incident Narrative

ON 7/10/23, AN EMPLOYEE AT ALLENTOWN STATION WAS CONDUCTING A STATION CHECK. WHILE WALKING THROUGH THE YARD THE EMPLOYEE IDENTIFIED PRODUCT AT APPROXIMATELY 09:30 AM NEAR UNIT 3'S SUCTION AND DISCHARGE VALVES. IT WAS DETERMINED AT 10:35 AM THE PRODUCT DISCOVERED WAS AN ACTIVE RELEASE. THE UNIT 3 DISCHARGE VALVE WAS FOUND TO BE WEEPING THROUGH 3 BOLTS ON THE BONNET. THE OSRO WAS ALREADY AT THE STATION PERFORMING ALTERNATIVE WORK AT THE TIME THE RELEASE WAS DISCOVERED. NRC WAS NOTIFIED ONCE IT WAS DETERMINED THE $50K THRESHOLD WAS GOING TO BE EXCEEDED. SUBSEQUENT ANALYSIS DETERMINED THAT THE RELEASE STARTED ON 6/30/23 THE CAUSE OF THE FAILURE IS UNDER INVESTIGATION. UPDATE 9/20/23 - AN INVESTIGATION DETERMINED THE RELEASE WAS COMING FROM THREE BOLTS ON THE UNIT 3 DISCHARGE VALVE BONNET AS PER VISUAL CONFIRMATION OF THE SAME. THE BONNET WAS SEPARATED TO INVESTIGATE AND REPAIR AND REASSEMBLE WITH A NEW O-RING. THE REMOVED O-RING WAS EXAMINED AND FOUND TO BE IN A GOOD CONDITION WITHOUT VISUAL DAMAGE OR DEFECTS AND WITHOUT EVIDENCE OF BEING PINCHED OR DISPLACED FROM THE SEALING GROOVE IN THE INSTALLATION. THE BONNET AND VALVE BODY SEALING SURFACES WERE INSPECTED AND CONFIRMED TO HAVE ADEQUATE SURFACE QUALITY FOR DESIRED SEAL PERFORMANCE. AS A PREEMPTIVE MEASURE, THE SEALING SURFACES WERE CLEANED AGAIN BEFORE REPAIR. THE SAME BOLTING PROCEDURE WAS FOLLOWED TO THE SAME TORQUE VALUES. A SPECIFIC FAILURE MODE COULD NOT BE IDENTIFIED AS THE O-RING AND SEALING SURFACES WERE IN GOOD CONDITION AND THE RECOMMENDED ASSEMBLY AND TORQUE METHODS WERE FOLLOWED.