GUARDIAN PIPELINE, LLC

Incident Narrative

ON MAY 2, 2011 AT APPROXIMATELY 08:25 AM A LANDOWNER CALLED THE GUARDIAN RIGHT-OF WAY AGENT TO REPORT A POSSIBLE GAS LEAK. THE RIGHT-OF WAY AGENT NOTIFIED OPERATIONS WHICH INVESTIGATED THE LEAK SITE. THE INVESTIGATION REVEALED BUBBLES IN STANDING WATER, IN A CULTIVATED FIELD. GUARDIAN OPERATIONS PERSONNEL CONFIRMED THAT IT WAS A GAS LEAK AND PROCEEDED TO ISOLATED THE PIPELINE AND REDUCED THE PRESSURE FROM 803 PSIG DOWN TO 185 PSIG. THE LINE WAS EXPOSED AND A WELD DEFECT WAS SUSPECTED IN A 30"" GIRTH WELD WHICH WAS ON A 8 FOOT LONG JOINT OF PIPE USED FOR REPAIR OF A DENT FOUND DURING THE CALIPER PIG RUN DURING THE ORIGINAL CONSTRUCTION. THE PIPELINE WAS BLOWN DOWN AND A 40 FOOT PIECE OF 30"" .375"" WALL GRADE X70 PRETESTED PIPE WAS INSTALL AT THE LEAK LOCATION. THE PIPELINE WAS RETURNED TO SERVICE ON MAY 5, 2011. A FAILURE ANALYSIS AND METALURGICAL STUDY WAS COMPLETED ON THE FAILED GIRTH WELD. THE REPORT INDICATES THE LEAKAGE WAS DUE TO LACK OF FUSION IN THE WELD AT THE 6 O'CLOCK POSITION ON THE GIRTH WELD AND WIDE WELD GAP DUE TO MISALIGNMENT. IN ADDITION TO THE WIDE ROOT GAP, THE USE OF ONLY TWO FILL PASSES IN THE AREA OF THE LEAKAGE ALSO CONTRIBUTED TO THE LACK OF FUSION AND RESULTING LEAK.