"GULF RUN TRANSMISSION, LLC"

Incident Narrative

"ON 2/15/2025 THE VERNON COMPRESSOR STATION LOST COMMERCIAL POWER. IN ADDITION, THE EMERGENCY GENERATOR FAILED TO START, AND THE STATION BATTERY UPS SYSTEM FAILED TO SWITCH TO BATTERY BACKUP. THE UPS IS USED TO MAINTAIN POWER TO STATION NETWORKS, PLC'S, AND HMIS FOR SHORT PERIODS OF TIME UNTIL EITHER COMMERCIAL OR EMERGENCY GENERATOR POWER BECOMES AVAILABLE. WITH NO POWER, A NORMAL STOP COMMAND WAS ISSUED TO ALL THREE STATION TURBINES. THE TURBINES STOPPED, THE UNIT BLOWDOWN VALVES OPENED, AND THE FUEL SUPPLY VALVES CLOSED. THE STATION ESD BLOWDOWN VALVES ARE DESIGNED TO DEFAULT TO THE FAIL-OPEN POSITION AND MUST BE MANUALLY RESET. STATION BLOWDOWN VALVES WERE SET TO OPEN AT 55PSI. THE ESD PRESSURE DROPPED BELOW 50PSI, WHICH ACTIVATED THE VALVES, AND BEGAN RELIEVING THE STATION PRESSURE. TECHNICIANS ARRIVED ON LOCATION AND BLOCKED IN THE STATION DURING THE BLOWDOWN PROCESS, PRIOR TO A FULL STATION BLOWDOWN. CORRECTIVE ACTIONS TAKEN TO HAVE THE STATION BACK ONLINE BY 2/16/2025 AT 4:00AM. REMEDIAL ACTIONS TAKEN, SMALL LEAK WAS FOUND ON THE ESD SYSTEM. THE ESD PILOTS ON BLOWDOWN VALVES WERE RESET TO 30PSI AND THE SIDE GATE ESD PILOTS WERE REST TO 45PSI. ORIGINAL CONSTRUCTION DESIGN WAS CHANGED FROM UTILIZING ESD GAS AS PILOT PRESSURE TO POWER GAS. ALL REGULATORS WERE TESTED AND TRENDED TO ENSURE PROPER OPERATION. GENERATOR LOGIC ISSUES WERE IDENTIFIED AND CORRECTED, THEN MULTIPLE SIMULATED POWER LOSS SCENARIOS WERE RUN TO ENSURE THE GENERATOR TRANSFERRED PROPERLY AND CARRIED THE STATION LOAD."