PANHANDLE EASTERN PIPELINE CO

Incident Narrative

THE PLEASANT HILL 200 LINE IS 22-IN. OD X 0.281-IN. WT, API 5L GRADE X42, SEAMLESS PIPELINE. THE CAUSE OF THE COUPLING SEPARATION AT MP 31.5 WAS THE COMBINED EFFECT OF LOCAL LOSS OF SOIL COVER IN CONJUNCTION WITH RECENT HIGH RAINFALL. THE MONTH PRECEDING THE INCIDENT EXPERIENCED HISTORICALLY HIGH QUANTITIES OF RAINFALL. THE RESULTING WATER TABLE WAS HIGH ENOUGH TO PRODUCE UPWARD BUOYANT FORCES ON THE PIPE, WHILE THE PROBABLE SATURATION OF THE SOIL COVER REDUCED ITS BREAKOUT RESISTANCE. THE COMBINATION OF BUOYANT FORCES AND UPWARD THRUST FORCES PRODUCED BY AN APPARENT SMALL ANGULAR MISALIGNMENT AT THE SEPARATED COUPLING EXCEEDED THE UPTHRUST RESISTANCE OF THE SOIL. **THIS REPORT IS BEING SUBMITTED IN RESPONSE TO PHMSA'S REQUEST, (DOCKET ID PHMSA-2013-0028), FOR SUPPLEMENTAL REPORTS FROM OPERATORS WHO SUBMITTED REPORTS FOR INCIDENTS OCCURRING AFTER JANUARY 1, 2010, WITH ANY OF THE FOLLOWING: (1) ``PIPE GIRTH WELD'' WAS SELECTED AS THE ``ITEM INVOLVED IN INCIDENT'' IN PART C3 OF THE REPORT. THE REVISED REPORT COLLECTS DATA ABOUT THE PIPE ADJACENT TO THE GIRTH WELD. (2) ``FUNCTION OF PIPELINE SYSTEM'' IS NULL IN PART E5F OF THE REPORT. THE REVISED REPORT COLLECTS THE FUNCTION OF THE PIPELINE SYSTEM FOR ALL INCIDENTS.** THIS SUPPLEMENTAL REPORT IS TO ACKNOWLEDGE THAT THE TWO RELEVANT SECTIONS IN PHMSA'S REQUEST HAVE BEEN REVIEWED AND NO FURTHER ACTIONS WERE NEEDED.