SUNOCO PIPELINE L.P.

Incident Narrative

"ON 6/12/25 AT APPROXIMATELY 23:20, A LOCAL EMPLOYEE OBSERVED EVIDENCE OF A POTENTIAL GASOLINE RELEASE NEAR THE METER RUN MANIFOLD AREA AT MONTELLO PUMP STATION. GASOLINE WAS RELEASING FROM A FAILED DENSITOMETER PUMP SEAL ON THE 14-INCH 12006 MONTELLO-BALD EAGLE LINE SEGMENT. THE DENSITOMETER WAS ISOLATED TO STOP THE LEAK. APPROXIMATELY 5 BARRELS OF GASOLINE WAS RELEASED. LOCAL EMPLOYEES CLEANED UP RELEASED PRODUCT AND REMOVED CONTAMINATED SOIL. THE ACCIDENT WAS REPAIRED BY REPLACING THE DENSITOMETER PUMP. THE FAILED DENSITOMETER PUMP IS BEING SENT TO A THIRD PARTY LAB FOR ANALYSIS. THE CAUSE OF THE ACCIDENT IS STILL UNDER INVESTIGATION. A SUPPLEMENTAL REPORT WILL BE SUBMITTED ONCE THE INVESTIGATION IS COMPLETED. SUPPLEMENTAL & FINAL: THE INVESTIGATION DETERMINED THE CAUSE OF THE ACCIDENT WAS EQUIPMENT FAILURE WHICH WAS ATTRIBUTED TO THE PUMP REBUILD PROCESS BY A 3RD PARTY NOT BEING PERFORMED PROPERLY. THE PUMP UNIT WAS REBUILT AND HAD BEEN IN STORAGE SINCE OCTOBER 2024 PRIOR TO REINSTALLATION IN THE SYSTEM IN 2025. THE FAILURE AND LEAKAGE OF THE MECHANICAL SEAL OCCURRED FROM NOT HAVING THE MECHANICAL SEAL INSTALLED CORRECTLY. THE SHAFT SLEEVE AND SET SCREWS WERE NOT LOCKED INTO THE SHAFT RESULTING IN THE MECHANICAL SEAL STATIONARY ASSEMBLY FLOATING AXIALLY BACK AND FORTH ACROSS THE SHAFT. THE WORKING LENGTH FOR THE SEAL AS PRESCRIBED BY FLOWSERVE WAS COMPROMISED. THE ELASTOMER BELLOWS ASSEMBLY WAS NOT SUPPOSED TO SLIDE ON THE SHAFT. POSITIVE STATIC SEAL BETWEEN THE BELLOWS AND THE SHAFT, ALONG WITH THE FREE MOVEMENT OF THE BELLOWS MEANS THAT THERE WAS NO SLIDING ACTION AND CAN LEAD TO SHAFT DAMAGE BY FRETTING; HOWEVER, NO SIGNS OF FRETTING WAS FOUND. PROPER BELLOWS POSITION AND ATTACHMENT ENSURES THAT THE SEAL WILL AUTOMATICALLY COMPENSATE FOR NORMAL SHAFT RUN-OUT AND AXIAL MOVEMENTS. TO PREVENT REOCCURRENCE, THE FAILED UNIT WAS REPLACED WITH A UNIT COMPATIBLE WITH THE LINE'S FLOW RATE."