ONEOK GAS TRANSPORTATION, LLC

Incident Narrative

APPROXIMATELY 11:02PM ON FEBRUARY 26, 2022 GAS CONTROL WAS NOTIFIED BY NEARBY LANDOWNER OF LOUD NOISE NEAR RED OAK STATION. THE OGT EMPLOYEE RESPONDED AND WAS ONSITE AT 11:48PM. THE OGT EMPLOYEE HAD GAS CONTROL SHUT COMPRESSOR UNIT #4 DOWN UPON ARRIVAL AND DETERMINATION OF RELIEF VALVE VENTING. THE COMPRESSOR UNIT 4 WAS LOCKED OUT OF SERVICE UNTIL TESTING COULD BE PERFORMED. RELIEF VALVE WAS REMOVED ON MARCH 4, 2022 AND DEBRIS WAS NOTED IN THE VALVE BELOW, AND DEBRIS WAS REMOVED AS PART OF THE INSPECTION. RELIEF VALVE WAS FOUND TO BE IN GOOD REPAIR, AND WAS RE-TESTED TO VERIFY THE FUNCTIONALITY OF THE RELIEF WAS OPERATING PROPERLY, AND PLACED BACK INTO A READY FOR SERVICE STATUS. SUPPLEMENTAL REPORT WAS MADE TO CORRECT THE DATE OF THE NRC NOTIFICATION DATE. THE DATE OF NRC NOTIFICATION WAS 02/27/2022 NOT 03/27/2022. 06/16/2022--SUPPLEMENTAL REPORT WAS MADE TO UPDATE THE CAUSE OF THE INCIDENT DUE TO SUPPLEMENTAL INFORMATION RECEIVED FROM A PULSATION STUDY- VIBRATION WAS THE ROOT CAUSE OF THE INCIDENT BY CAUSING THE SETPOINT TO DRIFT BELOW THE SETPOINT.