SOUTHERN NATURAL GAS CO
gas_transmission Incident — — November 9, 2017
Incident Information
| Incident Date | November 9, 2017 |
| Operator | SOUTHERN NATURAL GAS CO |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 30.19635, -91.10086 |
Cause
| Cause | EQUIPMENT FAILURE |
| Subcause | THREADED CONNECTION/COUPLING FAILURE |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $400 |
| Emergency Response | $0 |
| Other Costs | $0 |
Location Map
Incident Narrative
AT 5:04PM ENGINE #10 RELIEF VALVE BEGAN VENTING GAS DUE TO A BROKEN SENSING LINE. THE UNIT WAS EMERGENCY STOPPED AT 5:23PM. THE TOTAL AMOUNT OF UNINTENTIONALLY NATURAL GAS RELEASED WAS 11,600 MCF. THE INITIAL INVESTIGATION SHOWED THAT THE 1/4-INCH PIPE NIPPLE ON THE RELIEF VALVE PILOT TEST PORT BROKE CAUSING THE RELIEF VALVE TO VENT. UPON FURTHER INVESTIGATION IT WAS DETERMINED THAT VIBRATION AND THE WEIGHT OF THE TEST ASSEMBLY MAY HAVE CONTRIBUTED TO THE FAILURE OF THE PIPE NIPPLE. THE NIPPLE WAS REPLACED WITH A MALE X FEMALE THREAD VALVE AND THE ENGINE WAS RETURNED TO SERVICE. THE PIR IS BASED ON THE LARGEST DIAMETER PIPE INSIDE THE COMPRESSOR BUILDING, NOT THE NIPPLE THAT FAILED.
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.