EXPLORER PIPELINE CO

Incident Narrative

ON APRIL 11, 2019 AT 14:35 AN EMPLOYEE WAS AT THE CEDAR BAYOU METER STATION AND OBSERVED A RELEASE FROM A VALVE ASSOCIATED WITH THE METER STATION BYPASS LINE. THE BYPASS WAS ISOLATED, APPROPRIATE NOTIFICATIONS WERE MADE, AND THE EMPLOYEE RESPONDED TO THE RELEASE. THE DIRECT SOURCE OF THE RELEASE WAS FROM A DAMAGED O-RING AND BACKUP U-CUPS ROM THE VALVE. THE INTERNAL O-RING WAS THE ORIGINAL O-RING. THE VALVE WAS REPAIRED, AND THE DAMAGED O-RING AND U-CUPS WERE SUBMITTED TO A THIRD-PARTY FOR A FAILURE ANALYSIS. THE NRC WAS NOTIFIED ON 4.15.2019, ONCE IT WAS FIRST THOUGHT THE COST FOR THE RELEASE WOULD MEET OR EXCEED 50,000 DOLLARS AS PER 195.52(A)(3). THE 48-HOUR NRC UPDATE WAS PROVIDED ON 4.17.2019. REPORT NUMBER 1242980 WAS PROVIDED FOR THE 48-HOUR UPDATE. THE CONCLUSION OF THE FAILURE ANALYSIS AND ROOT CAUSE INDICATES AN OBVIOUS TEAR SUFFERED FROM ABRASION AND EVENTUAL LOSS OF MATERIAL WITH ASSOCIATED EROSION DUE TO FLOW DURING LEAKING NEAR THE NECKED REGION AND CRACK. OTHER AREAS AWAY FROM THE SEPARATION OF THE O-RING SHOW VARYING DEPTHS OF ABRASIVE WEAR (AWAY FROM THE LEAK) WHICH INDICATES THAT PHYSICAL ABRASION LIKELY PLAYED A LARGE ROLE IN THE EVENTUAL LEAK. ABRASION EVIDENCE WAS ALSO FOUND ON THE OD SURFACE OF THE U-CUPS. THE O-RING MATERIALS THEMSELVES ARE COMPOSED OF VITON WHICH IS KNOWN AND USED FOR ITS CHEMICAL RESISTANCE PROPERTIES. THE LACK OF OBVIOUS DEGRADATION (CRAZING AND/OR INTERNAL SEPARATIONS-BLISTERS) INDICATES THE MATERIAL WAS NOT AFFECTED BY THE SERVICE AND FTIR OF CROSS-SECTIONS INDICATES NO INGRESS OF CHEMICALS INTO THE RUBBER. THE FAILURE OF THE O-RING APPEARS TO BE OF A PHYSICAL NATURE RATHER THAN A CHEMICAL ONE.