COLORADO INTERSTATE GAS CO
gas_transmission Incident — — December 2, 2010
Incident Information
| Incident Date | December 2, 2010 |
| Operator | COLORADO INTERSTATE GAS CO |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 38.72554, -102.93045 |
Cause
| Cause | MATERIAL FAILURE OF PIPE OR WELD |
| Subcause | ORIGINAL MANUFACTURING-RELATED (NOT GIRTH WELD OR OTHER WELDS FORMED IN THE FIELD) |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $44,200 |
| Emergency Response | $0 |
| Other Costs | $0 |
Location Map
Incident Narrative
ON DECEMBER 2, 2010, COLORADO INTERSTATE GAS (CIG) LOCAL OPERATING PERSONNEL NOTICED A PRESSURE DROP ON CIG'S 20-INCH LINE 2A AT THE COMPANY'S KIT CARSON COMPRESSOR STATION AT APPROXIMATELY 7:58 AM MST. FIELD INVESTIGATION REVEALED THAT A RUPTURE HAD OCCURRED APPROXIMATELY 9 MILES WEST OF THE COMPRESSOR STATION NEAR CHEYENNE COUNTY ROAD J. THE PIPELINE WAS ISOLATED. THERE WAS NO FIRE AND THERE WERE NO INJURIES NOR FATALITIES. POST INCIDENT INVESTIGATION REVEALED THAT THE RUPTURE ORIGINATED FROM AN AXIAL CRACK LOCATED IN THE HEAT AFFECTED ZONE (HAZ) OF THE ERW LONGITUDINAL SEAM WELD AT THE 6 O'CLOCK POSITION OF THE PIPELINE. THE CRACK GROWTH WAS DUE TO AN ENVIRONMENTALLY ASSISTED HYDROGEN STRESS CRACKING MECHANISM. THE ORIGINAL MANUFACTURING PROCESS CREATED A HARDENED MICROSTRUCTURE IN THE HAZ OF THE LONGITUDINAL SEAM WELD RENDERING IT SUSCEPTIBLE TO THIS CONDITION. MANUFACTURING IMPERFECTIONS, IN THE FORM OF SURFACE LAPS AND PREEXISTING CRACKS, ADJACENT TO THE LONGITUDINAL SEAM WELD SERVED AS STRESS CONCENTRATORS AND SITES FOR CRACK INITIATION DURING 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.