QUESTAR PIPELINE COMPANY
gas_transmission Incident — — January 14, 2013
Incident Information
| Incident Date | January 14, 2013 |
| Operator | QUESTAR PIPELINE COMPANY |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 39.94889, -109.77583 |
Cause
| Cause | EQUIPMENT FAILURE |
| Subcause | MALFUNCTION OF CONTROL/RELIEF EQUIPMENT |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $1,300 |
| Emergency Response | $300 |
| Other Costs | $0 |
Location Map
Incident Narrative
FREEZE IN SENSING LINE TUBING TO PILOT-OPERATED RELIEF VALVE CAUSED THE 6""X8"" RELIEF VALVE TO OPEN AND VENT GAS AT APPROXIMATELY 726 PSIG, WHICH IS WELL-BELOW ITS SET-POINT OF 827 PSIG. DURING THE VENTING PROCESS THE TUBING TO THE SENSING LINE FAILED, WHICH PREVENTED THE RELIEF VALVE FROM RE-SEATING AND RESULTED IN VENTING GAS FOR APPROXIMATELY 4 HOURS AND 55 MINUTES. FIELD OPERATIONS ARRIVED ON-SITE AND ISOLATED THE RELIEF VALVE BY CLOSING THE 6"" ISOLATION VALVE INSTALLED IMMEDIATELY UPSTREAM OF THE RELIEF VALVE. THE PILOT VALVE AND SENSING LINE TUBING WERE REPAIRED AND THE RELIEF VALVE WAS PLACED BACK INTO SERVICE.
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.