TEXAS EASTERN TRANSMISSION, LP

Incident Narrative

ON THE MORNING OF AUGUST 8, 2023, TEXAS EASTERN BEGAN AN ANOMALY DIG TO EXPOSE A GEOMETRY FEATURE (BUCKLE/DENT) AT THE 6 O-CLOCK POSITION. THE LINE IN THIS AREA WAS VERY DEEP (>11-FEET). THE UPSTREAM VALVE WAS CLOSED AT 09:39 E.T. TO LOWER THE LINE PRESSURE FOR THE EXCAVATION AND REPAIR. DOWNSTREAM COMPRESSION WAS USED TO HELP PULL THE PRESSURE DOWN. WHILE EXCAVATING THE ANOMALY, THE CREW IDENTIFIED INDICATIONS OF A LEAK AT APPROXIMATELY 17:00 ET. AN OPERATIONS TEAM WAS THEN CALLED IN TO INVESTIGATE THE SUSPECTED LEAK. AT 19:28 ET THE DOWNSTREAM VALVE WAS CLOSED TO FULLY BLOWDOWN THE LINE. AT APPROXIMATELY 20:30 E.T. IT WAS DECIDED THAT REPAIRS COULD LIKELY EXCEED THE PHMSA REPORTING COST THRESHOLD. AT 21:09 ET THE NATIONAL RESPONSE CENTER WAS NOTIFIED. THE BLOWDOWN WAS COMPLETED ON AUGUST 9, 2023, AT APPROXIMATELY 12:30 ET. THE LINE WAS THEN EXCAVATED AND THE PIPING IN AREA OF THE SUSPECTED LEAK WAS CUT OUT AND REMOVED. AN AIR PRESSURE TEST WAS THEN PERFORMED ON THE CUT-OUT SEGMENT AND A SMALL THROUGH WALL FEATURE ON THE WELD (12 O-CLOCK) ADJACENT TO THE GEOMETRY FEATURE WAS IDENTIFIED. THE PIPE WAS THEN TRANSPORTED TO A LAB FOR FURTHER ANALYSIS AS TO THE CAUSE. 04/24/2024 SUPPLEMENTAL UPDATED PART G - APPARENT CAUSE AND PART J - INTEGRITY INSPECTIONS THE CAUSE OF THE LEAK WAS TENSILE OVERLOADING OF THE PIPE RESULTING IN A 1.5-INCH DUCTILE FAILURE AT TOE OF THE GIRTH WELD. A BENDING MOMENT EXERTED HIGH TENSILE STRESS NEAR THE 12:00 O'CLOCK LOCATION AND HIGH COMPRESSIVE STRESS THE 6:00 O'CLOCK LOCATION, CAUSING THE LEAK AT THE 12:00 O'CLOCK LOCATION AND A BUCKLE AT THE 6:00 O'CLOCK LOCATION.