SOUTHERN STAR CENTRAL GAS PIPELINE, INC

Incident Narrative

ON 2/14/2020 AT 12:26 AM LOCAL TIME, SOUTHERN STAR CENTRAL GAS PIPELINE (SSCGP) GAS CONTROL RECEIVED A CALL FROM THE OPERATOR AT THE WELDA COMPRESSOR STATION OF A POSSIBLE RELIEF VALVE ACTIVATION. GAS CONTROL CONFIRMED A PRESSURE DROP BUT THERE WAS NO MAOP EXCEEDANCE. GAS CONTROL RECEIVED ANOTHER CALL FROM THE ANDERSON COUNTY SHERIFF'S DEPARTMENT AT 12:31 AM DUE TO THE SOUND OF HISSING GAS. AT 12:34 AM THE WELDA OPERATOR IDENTIFIED THE LOCATION OF THE ACTIVATED RELIEF VALVE. SINCE THIS WAS NOT AN OVERPRESSURE EVENT, THE RELIEF VALVE WAS ISOLATED BY 12:48 AM. INITIAL GAS LOSS CALCULATIONS INDICATED THAT THIS WAS NOT A REPORTABLE EVENT. THE RELIEF VALVE WAS REMOVED, REBUILT AND PLACED BACK IN SERVICE AT APPROXIMATELY 10:00 AM ON 2/14/2020. THE GAS LOSS WAS RECALCULATED AT 9:49 AM AND IT WAS DETERMINED THAT ACTUAL GAS LOSS WAS APPROXIMATELY 7.1 MMCF. THE CALL TO THE NRC WAS PLACED AT 10:32 AM TO MAKE THE NOTIFICATION OF THE GAS LOSS AT THE RELIEF VALVE. THE NRC WAS ALSO NOTIFIED THAT THERE WERE NO INJURIES, FIRE OR PROPERTY DAMAGE AS A RESULT OF THIS RELEASE. THE FOLLOW UP CALL TO THE NRC WAS MADE ON 2/14/2020 AT 2:34 PM TO CONFIRM THAT THE EVENT WAS OVER AND THERE WERE NO INJURIES OR PROPERTY DAMAGE. THE TEMPERATURE AT THE TIME OF THE RELIEF VALVE MALFUNCTION WAS 2 DEGREES F. WHEN THE RELIEF VALVE WAS REMOVED FOR REBUILD, DEBRIS WAS PRESENT IN THE PILOT. SSCGP DETERMINED THAT DEBRIS IN THE PILOT CAUSED THE RELIEF VALVE TO MALFUNCTION.