TRANSCONTINENTAL GAS PIPE LINE COMPANY

Incident Narrative

DURING ANOMALY INSPECTION OF THE PIPE, ONE ID CONNECTED LACK OF FUSION AND TWO ID PLANAR DEFECTS WERE FOUND IN THE ILI CALL AREAS. PLANAR DEFECT #1 WAS FOUND TO BE 100.0% THRU-WALL AND WAS LEAKING AFTER ABRASIVE SANDBLASTING OPERATIONS WERE COMPLETED. PREDICTED ILI TOOL DATA AND ACTUAL LOCATION OF ANOMALY WERE FOUND TO BE IN THE SAME LOCATION. PER WILLIAMS PROCEDURES, A PIPE REPLACEMENT WAS PERFORMED TO COMPLETE THE MITIGATION FOR THIS DIG SITE. MAGNETIC PARTICLE, PAUT AND STRAIGHT BEAM ULTRASOUND INSPECTIONS WERE PERFORMED AT THE UPSTREAM AND DOWNSTREAM TIE-IN LOCATIONS FINDING NO RELEVANT INDICATIONS. LABORATORY FINDINGS: SCANNING ELECTRON MICROSCOPIC (SEM) EXAMINATIONS ITEM - A PORTION OF THE CRACK SURFACE, DETECTED DURING ULTRASONIC EXAMINATIONS REVEALED AFTER SECTIONING. FINDINGS - RUST COLORED DEPOSITS ORIGINATING ON THE INTERNAL SURFACE COVERED A PORTION OF THE FRACTURE SURFACE IN THE AREAS IDENTIFIED IN UT EXAMINATION. THESE AREAS WERE CONFIRMED TO BE CORRODED AND PITTED UNFUSED WELD METAL. METALLOGRAPHIC EXAMINATIONS SPECIMEN - A TRANSVERSE SECTION ACROSS THE REVEALED CRACKS. FINDINGS - THE CRACKS WERE CONFIRMED TO BE LONGITUDINAL, FOLLOWING A VIRTUALLY STRAIGHT PATH ALONG WHAT APPEARS TO BE THE ORIGINAL WELD LINE OF FUSION WITH A REPAIR WELD PRESENT ON THE EXTERNAL SURFACE OF THE SAMPLE. COMMENTS THE CRACK INDICATIONS WERE FOUND TO BE CORRODED AND PITTED AREAS OF THE UNFUSED WELD METAL ORIGINATING ON THE INTERNAL SURFACE OF THE PIPE FOLLOWING THE WELD LINE OF FUSION WITH A REPAIR WELD PRESENT ON THE EXTERNAL SURFACE OF THE PIPE. THE CRACKS APPEAR TO HAVE BEEN INTRODUCED DURING MANUFACTURING