PLANTATION PIPE LINE CO

Incident Narrative

A RESIDENT CALLED THE CONTROL CENTER AT 15:42 ON 8/21/2014 TO REPORT PRODUCT NEAR THE RIGHT OF WAY. ONCE THE LEAK SITE WAS DISCOVERED AND THE PIPELINE EXCAVATED, A FIELD EXAMINATION DETERMINED THE LONGITUDINAL WELD OF A TYPE ""B"" SLEEV HAD A CRACK. THE TYPE ""B"" SLEEVE WAS INSTALLED IN 1979 TO REPAIR A DENT IN THE PIPELINE DISCOVERED FROM A KALIPER PIG SURVEY. THE LOCATION OF THE PRODUCT RELEASE WAS A DENT CENTERED AT THE 6:00 CIRCUMFERENTIAL POSITION IN NPS 30 LINEPIPE THAT WAS SLEEVED IN 1979. METALLURGICAL ANALYSIS INDICATES THE LEAK PATH INVOLVED A 2 3/8 INCH LONGITUDINAL CRACK IN THE SHOULDER OF THE DENT AT THE 5:30 CIRCUMFERENTIAL POSITION AND AN 83/4-INCH LONG CRACK IN THE SLEEVE LONGITUDINAL WELD AT THE 3:00 CIRCUMFERENTIAL POSITION. THE LONGITUDINAL EDGES OF THE BOTH SLEEVE PIECES WERE SOMEWHAT FLAT RATHER THAN FULLY CONTOURED TO THE OUTSIDE DIAMETER OF THE LINEPIPE. THIS CREATED PEAKING CONDITIONS AT BOTH LONGITUDINAL WELD SEAMS IN THE SLEEVE. THE LONGITUDINAL SEAM WELD AT 3:00 THAT LEAKED ALSO EXHIBITED A WIDE ROOT GAP AND THE BACKING STRIP BENEATH THE SLEEVE DID NOT EXTEND FULLY ACROSS THE GAP. THE RESULT OF THE FIT-UP WAS A WELD WITH INCOMPLETE PENETRATION AND NON-FUSION ALONG THE EDGES OF THE ROOT, PARTICULARLY ALONG THE EDGE THAT LACKED BACKING. THE MOST LIKELY SEQUENCE OF EVENTS IS THAT THE DENT LEAKED FIRST. AFTER THE DENT SUBSEQUENTLY LEAKED AND PRESSURIZED THE SLEEVE, THE CAP PASS OF THE LONGITUDINAL SLEEVE WELD COULD NOT SUPPORT THE LOAD AND FRACTURED BY TENSILE OVERLOAD. RESIDUAL IMPACTS ARE BEING ADDRESSED UNDER THE OVERSIGHT OF THE ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT, GROUNDWATER SECTION.