SOUTHEAST SUPPLY HEADER, LLC

Incident Narrative

ON JANUARY 21, 2010, A SOUTHERN PINES ELECTRIC (SPE) EMPLOYEE RESPONDING TO POTENTIAL TORNADO DAMAGE TO THEIR POWER LINES WAS WALKING DOWN OUR RIGHT-OF-WAY AND SAW BUBBLES IN WATER THAT HAD POOLED ALONG THE RIGHT-OF-WAY. THE SPE EMPLOYEE CALLED THE SESH SYSTEM CONTROL CENTER AT 12:30 HRS. TO REPORT WHAT HE SUSPECTED TO BE A PIPELINE LEAK. SYSTEM CONTROL DISPATCHED AN SESH EMPLOYEE WHO ARRIVED ON SITE AT 13:30 HRS. AND SUSPECT THAT OUR PIPELINE MAY HAVE A PINHOLE LEAK. THE LOCATED WAS AT CONSTRUCTION STATION 4583+53, IN COPIAH COUNTY, MS. THE LOCATION WAS EXCAVATED AND AT 19:25 HRS. THE LEAK WAS CONFIRMED AS A GIRTH WELD LEAK. ON JANUARY 22, 2010 THE LINE WAS BLOWN DOWN AND A SLEEVE WAS PLACE ON THE LINE UNTIL PERMANENT REPAIRS COULD BE MADE. ON FEBRUARY 7, 2010 PERMANENT REPAIRS WERE MADE TO THE LINE BY PIPE REPLACEMENT. FACTS, CIRCUMSTANCES, AND CONDITIONS THAT MAY HAVE CONTRIBUTED DIRECTLY OR INDIRECTLY TO CAUSING THE INCIDENT THE LEAK WAS THE RESULT OF A THOUGH-WALL CRACK IN THE GIRTH WELD JOINING THE 1.000' WT INDUCTION BEND TO 0.600' WT PIPE TRANSITION PIPE. THE CRACK WAS THE RESULT OF HYDROGEN-ASSISTED CRACKING (HAC). HAC MOST LIKELY THE RESULT OF MARGINAL HEAT INPUT OR PRE-HEAT AT THE 6 O'CLOCK POSITION WHICH PROMOTED RETENTION OF DIFFUSIBLE HYDROGEN WITHIN THE WELD. MARGINAL HEAT INPUT WAS LIKELY THE RESULT OF COLD AND WINDY CONDITIONS PRESENT DURING THE DAY OF WELDING. THERE WAS NO EVIDENCE OF CRACKING ELSEWHERE IN THE WELD. THE CRACK OCCURRED ON THE FACTORY END OF AN INDUCTION BEND AT A LOCATION WITH OPTIMUM WELD FIT-UP. IT WAS CONCLUDED THAT WELD FIT-UP DID NOT PLAY ANY ROLE IN THE INITIATION OF THE HYDROGEN CRACK. THE PIPELINE HAD BEEN HYDROSTATICALLY TESTED FOR 24 HOURS AT A MINIMUM PRESSURE CORRESPONDING TO A HOOP STRESS IN EXCESS OF 100% OF SMYS. PART C ADDITION THE PIPED JOINTED AT THE GIRTH WELD WERE OF TWO DIFFERENT WT. PART C HAD THE DATA FOR THE BEND, 42 "" DIAMETER 1"" WT PIPE. THE FOLLOWING IS THE DATA FOR THE PUP, 42 "" DIAMETER .600 "" WT. API 5L GRADE X70, PSL 2, 42' OD X .600' WT HELICAL WELDED LINE PIPE MANUFACTURED BY CORINTH PIPEWORKS IN 2007. 70,000 SMYS.