ANR PIPELINE CO

Incident Narrative

ON NOVEMBER 6 AT 17:30 CT, ANR PIPELINE'S GAS CONTROL RECEIVED AN EMERGENCY SHUTDOWN (ESD) ALARM AT DELHI COMPRESSOR STATION LOCATED AT 1984 HWY 80 W, DELHI, LA 71232 (32.46707, -91.59751). WHEN THE ALARM WAS DETECTED, A TECHNICIAN WAS DISPATCHED TO THE COMPRESSOR STATION TO INVESTIGATE. UPON ARRIVAL AT THE SITE AT 17:40 CT, THE TECHNICIAN DISCOVERED NATURAL GAS BEING RELEASED THROUGH THE STATION'S BLOWDOWN STACKS. IMMEDIATE ACTION WAS TAKEN BY VERIFYING NO EMERGENCY EXISTED AND CLOSING THE VALVES, WHICH ENDED THE RELEASE AT 17:44 CT. UNINTENTIONAL GAS LOSS WAS CALCULATED TO 5.0 MILLION CUBIC FEET (MMCF). NO PROPERTY DAMAGE OR INJURIES WERE DOCUMENTED, AND NO EVACUATIONS WERE REQUIRED. FOLLOWING THE RELEASE, INITIAL SITE INSPECTIONS WERE COMPLETED TO LOOK FOR EVIDENCE OF FIRE OR OTHER DAMAGE. NO DAMAGE WAS OBSERVED, AND THE STATION WAS PLACED BACK INTO PARTIAL SERVICE AT 23:00 CT ON NOVEMBER 6. WHEN THE SYSTEM ACTIVATED, STATION ISOLATION VALVE 501-13-25 FAILED TO FULLY CLOSE RESULTING IN THE UNINTENTIONAL RELEASE OF GAS. FOLLOWING THE INCIDENT, VALVE 501-13-25 WAS REMOVED FROM SERVICE FOR INSPECTION. A POPPET BLOCK VALVE, ATTACHED TO THE VALVE OPERATOR WAS REMOVED, DISASSEMBLED, AND INSPECTED FOR POTENTIAL DAMAGE. DAMAGED AND WORN SEALS ON THE POPPET VALVE WERE IDENTIFIED WHICH PREVENTED THE VALVE FROM FULLY CLOSING WHEN ACTUATED. THE POPPET BLOCK VALVES ASSOCIATED WITH VALVE 501-13-25 WERE CLEANED AND THE SEALS WERE REPLACED. AFTER REPAIRING THE VALVES, AN ESD SYSTEM INSPECTION WAS COMPLETED ACCORDING TO PROCEDURES ON NOVEMBER 17, 2020. THE TEST WAS INITIATED BY TRIGGERING THE FLAME DETECTORS AND THEN MONITORING ALL EMERGENCY SYSTEM VALVES FOR OPERATIONS AND TIMING. DURING THE TEST, ALL SYSTEM VALVES PROPERLY OPERATED AND FULLY CLOSED.