COLUMBIA GAS TRANSMISSION, LLC — Gas transmission and gathering — incident on 2015-11-26

Gas transmission and gathering incident in ARTEMAS, BEDFORD COUNTY County, PA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 2618 NATURAL GAS released, $0 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20150152.

Operator ID: 2616.

Reported incident date: 11/26/2015 12:37.

Location detail: RELIEF VALVE

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON NOVEMBER 26, 2015, A COLUMBIA GAS TRANSMISSION, LLC (COLUMBIA) FACILITY WAS SUBJECT TO AN EVENT DUE TO AN UNINTENDED ACTIVATION OF AN INTERMEDIATE 4-IN RELIEF VALVE (RV) THAT EXCEEDED 3,000 MCF OF NATURAL GAS (MATERIAL). THIS RV IS LOCATED ON THE DISCHARGE LINE OF UNIT NO. 2 IN ARTEMAS COMPRESSOR STATION (CS). THIS FACILITY IS LOCATED NEAR THE TOWN OF ARTEMAS IN BEDFORD COUNTY, PENNSYLVANIA. COLUMBIA OWNS, OPERATES AND MAINTAINS THIS TRANSMISSION FACILITY. AFTER RECEIVING A CALL FROM COLUMBIA S MONITORING CENTER ABOUT A FAULT AT UNIT NO. 2, COLUMBIA OPERATIONS PERSONNEL RESPONDED TO THIS EVENT TO ADDRESS THE FAULTED UNIT. UPON REACHING THE SITE AND IDENTIFYING THE SOURCE OF THE BLOWING NOISE, COLUMBIA PERSONNEL ISOLATED THE PIPELINE TO PREVENT ADDITIONAL FLOW OF MATERIAL THROUGH THIS RV WHERE THE AREA WAS MADE SAFE AND SECURED. THERE WAS NO PRESENCE OF FIRE OR EXPLOSION IN LIEU OF THE MATERIAL RELEASE. THE INITIAL ASSESSMENT OF THIS INCIDENT INDICATED THAT A CONTRIBUTING FACTOR WAS A CHECK VALVE LOCATED UPSTREAM OF THE RV HAD FAILED TO OPERATE. HENCE, PROVIDING CONTINUOUS FLOW TO THE RV, WHICH IN TURN CONTINUED TO RELIEVE THE ADDITIONAL FLOW (AS IT WAS DESIGNED TO). UNIT NO. 2 AND THE ASSOCIATED PIPING WERE KEPT ISOLATED PENDING FURTHER INVESTIGATIONS, WHEREAS THE REST OF THE FACILITY WAS KEPT RUNNING IN ITS NORMAL OPERATIONAL MODE. THE FAILURE ANALYSIS INVESTIGATION REPORT IDENTIFIED AN ELEVATED LEVEL OF VIBRATION MAY HAVE BEEN A CONTRIBUTING FACTOR THAT TRIGGERED THE FAILURE OF THE HEADER CHECK VALVE (CV), HENCE INITIATING THE CHAIN OF EVENTS. THE CV FUNCITONS AS ASEPARATOR BETWEEN THE INTERMEDIATE DISCHARGE HEADER FROM THE HIGH PRESSURE DISCHARGE HEADER. AS A CORRECTIVE ACTION, ADDITIONAL BRACING WAS INTRODUCED TO THE SUSPECT SUBJECT PIPING TO ATTENUATE THE VIBRATION.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $4,922 reported total cost, $4,563.826 in 1984 dollars, $5,603.685 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.