EXXONMOBIL PIPELINE CO

Incident Narrative

AT 1:23 A.M., EXXONMOBIL PIPELINE COMPANY (EMPCO) OPERATIONS CONTROL CENTER (OCC) RECEIVED A CALL FROM EXXONMOBIL BAYTOWN REFINERY REGARDING A SMELL OF GASOLINE IN THE AREA NEAR BAYTOWN PRODUCTS 1 STATION. IMMEDIATELY THEREAFTER, OCC SHUTDOWN THE POTENTIALLY AFFECTED PIPELINE SEGMENT AND NOTIFIED FIELD OPERATIONS. UPON DEVELOPMENT OF SAFETY PLAN, TECHNICIAN ENTERED SITE AT 2:00 A.M. TO INVESTIGATE. AT 4:00 A.M., THE TECHNICIAN NOTICED THAT THE TRUNNION BOLTS ON THE VERY BOTTOM OF THE VALVE HAD BACKED OUT FROM THE VALVE BODY. DUE TO CLOSE THE PROXIMITY OF THE VALVE TO THE GROUND SURFACE, THE BOLTS WERE NOT READILY APPARENT. THE RELEASE WAS REPORTED TO NATIONAL RESPONSE CENTER AT 4:26 A.M. AND RAILROAD COMMISSION OF TEXAS AT 4:36 A.M. THE SITE WAS THEN ISOLATED, AND SPILL CLEAN-UP WAS COMPLETED. POST-INCIDENT ANALYSIS INDICATES THAT THE TRUNNION BOLTS WERE MIS-SIZED (AT LEAST 1/4"" TOO SHORT) AT THE TIME OF THE 2014 VALVE REBUILD BY THE THIRD-PARTY MANUFACTURER/VENDOR. FOLLOWING THE INCIDENT, AN EXPERIENCED CONTRACTOR AND FIELD ENGINEER REVIEWED THE VALVE SPECS AND REINSTALLED THE EQUIPMENT TO PROPER SPECS USING MORE APPROPRIATELY-SIZED BOLTS. BASED UPON THE VALVE DESIGN AND MECHANICS, THE RELEASE APPEARS TO HAVE OCCURRED ONLY DURING AN APPROXIMATE 4-SECOND PERIOD WHILE THE VALVE WAS IN TRANSIT AND WAS CALCULATED TO BE APPROXIMATELY 2.5 BARRELS. IN TERMS OF PREVENTIVE MEASURES IN THE FUTURE, FIELD OPERATIONS HAS INFORMED THE VENDOR/MANUFACTURER OF THE INCIDENT AND TO REVISE SPECS TO HAVE THE CORRECT SIZE TRUNNION BOLTS. IN ADDITION, FIELD OPERATION WILL BE ASSESSING SIMILAR 4-WAY VALVES. [9/19/2018- BRIAN PIERZINA, SR. ACCIDENT INVESTIGATOR, ADVISED TO REVISE THE TIME OF THE INCIDENT FROM 4:00 A.M. TO 1:23 A.M. AND TYPE OF LEAK (PART C) FROM ""OTHER"" TO ""SEAL OR PACKING.""]