SOUTHERN NATURAL GAS CO
gas_transmission Incident — — November 5, 2014
Incident Information
| Incident Date | November 5, 2014 |
| Operator | SOUTHERN NATURAL GAS CO |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 32.78772, -84.25427 |
Cause
| Cause | EQUIPMENT FAILURE |
| Subcause | MALFUNCTION OF CONTROL/RELIEF EQUIPMENT |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $300 |
| Emergency Response | $200 |
| Other Costs | $0 |
Location Map
Incident Narrative
ON NOVEMBER 5, 2014, AT 5:08 AM EST, GAS CONTROL SENT A START COMMAND TO INITIATE A START ON THOMASTON UNIT 3. TRENDING DATA INDICATES THAT AT 05:10 AM EST, DURING THE PURGE/PRESSURIZE SEQUENCE, THE UNIT VENT VALVE FAILED TO CLOSE AND THE START SEQUENCE FAILED. ALL AFFECTED VALVES SHOULD HAVE RETURNED TO THEIR NORMAL POSITIONS. AT 5:15 AM EST, GAS CONTROL RECEIVED A SEQUENCE ALARM INDICATING UNIT VALVES WERE OUT OF POSITION; THE PURGE VALVE REMAINED OPEN, RESULTING IN THE UNINTENDED RELEASE OF GAS THROUGH THE VENT VALVE. GAS CONTROL DISPATCHED A TECHNICIAN TO THE FACILITY. AT 06:28 AM EST, THE TECHNICIAN ARRIVED ON SITE, CHECKED THE COMPRESSOR AUTOMATION SYSTEM AND SENT A 'CLOSE' COMMAND TO THE PURGE VALVE AND IT CLOSED PROPERLY, STOPPING THE UNINTENDED GAS RELEASE. 1/21/2014 - UPDATE - FAULTY RELAY AND LOOSE WIRING CONTRIBUTED TO THE FAILURE OF THE VENT VALVE TO CLOSE.
About This Pipeline Incident
Pipeline incident data is reported to the Pipeline and Hazardous Materials Safety Administration (PHMSA). All significant incidents involving fatalities, injuries, or property damage over $50,000 must be reported.