SUNOCO PARTNERS MARKETING & TERMINALS LP

Incident Narrative

ON AUGUST 17, A CONTRACT PIPING CREW WAS WORKING ON THE SOUTH END OF THE 26-INCH CRUDE OIL TANK 1573 LINE LOCATED IN THE CENTRAL MANIFOLD AREA. THE CREW WAS REMOVING A SECTION OF PIPING IN ORDER FOR A NEW FLANGED SPOOL SECTION TO BE INSTALLED. THE LINE WAS OPENED; VACUUMED, AND DRAINED TO ALLOW FOR A COLD CUT TO BE MADE. ONCE LINE WAS CUT, THE CREW UNBOLTED THE SOUTH FLANGE AND REMOVED THE SPECTACLE BLIND ALONG WITH THE CUTOUT PIPE SPOOL SECTION. A BLIND FLANGE WAS INSTALLED ON THE SOUTH END. AN INFLATABLE ISOLATION PLUG WAS INSTALLED ON THE NORTH END OF THE PIPING WHERE THE COLD CUT HAD BEEN MADE. THE SEAL WAS CHECKED WITH A GAS MONITOR TO VERIFY NO VAPORS WERE PRESENT. ONCE A SEAL WAS VERIFIED THE PIPEFITTER BEGAN TO PREP THE WELD AREA FOR INSTALLATION OF A WELDED FLANGE USING AN ELECTRIC PORTABLE ANGLE GRINDER. SHORTLY AFTER STARTING THE PREP WORK, THE ISOLATION PLUG FAILED, AND A FLASH FIRE OCCURRED AT APPROXIMATELY 3:15 PM. AN NRC NOTIFICATION WAS PLACED ON 8/18/21 AT 17:39 (NRC# 1314098) A 48HR WAS PLACED ON 8/20/21 AT 17:13 (NRC # 1314284). INVESTIGATION OF THE ACCIDENT FOUND THAT AN INCORRECT ISOLATION TOOL WAS UTILIZED. THE ISOLATION TOOL FAILED DUE TO IMPROPER INSTALLATION AND MATERIAL INCOMPATIBILITY WITH PETROLEUM. THE FAILURE ALLOWED FLAMMABLE VAPORS TO ENTER THE HOT WORK AREA LEADING THE IGNITION.