WILLIAMS GAS PIPELINE - TRANSCO — Gas transmission and gathering — incident on 2010-02-10

Gas transmission and gathering incident in JOHNSON BAYOU, CAMERON County, LA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 18 NATURAL GAS released, $5,000 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20100015.

Operator ID: 19570.

Reported incident date: 2/10/2010 3:58.

Cause detail: THREADED CONNECTION/COUPLING FAILURE

Cause detail: 6" STRINER LID (YALE CAP CLOSURE) FAILED ALLOWING CONDENSATE AND GAS TO ESCAPE TO THE ATMOSPHERE. OPERATOR ON DUTY ISOLATED STRAINER POT WITH VALVING UPSTREAM AND DOWNSTREAM. GAS LOSS WITH CONDENSATE/SALTWATER WAS RELEASED. METALURGICAL REPORT REVEALED THE FOLLOWING FINDINGS: SEVERAL CIRCUMSTANCES WORKED IN COMBINATION TO ALLOW THE CAP TO FAIL AND COME OFF OF THE BARREL. THERE WAS A LOSS OF FIT-UP BETWEEN THE MATING THREADS ON THE CAP AND BARREL AS A RESULT OF CORROSION, WEAR, AND PRIOR MECHANICAL DAMAGE (POSSIBLE OVER-TIGHTENING AND/OR CROSSTHREADING). � THE CAP WAS TIGHTENED BY HAMMER BLOWS TO ITS DAMAGED EARS, WHICH RESULTED IN THE CAP BEING INSTALLED OFF-CENTER RELATIVE TO THE BARREL. � THE NUMBER OF THREADS CAPABLE OF CARING LOADS WAS REDUCED BY PRIOR DAMAGE TO NO MORE THAN TWO. � THE THREADS ON ONE SIDE OF THE CONNECTION WERE FULLY ENGAGED AND THE TRHEADS ON THE OPPOSITE SIDE WERE ONLY SLIGHTLY ENGAGED. � THE THREADS LOCATED 90� RELATIVE TO THE ENGAGED THREADS WERE ONLY PARTIALLY ENGAGED; THESE WERE OVERLOADED AND SHEARED OFF AT THE TIME OF FAILURE.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — THREADED CONNECTION/COUPLING FAILURE.

PHMSA indexed costs: $257,200 reported total cost, $140,932.951 in 1984 dollars, $345,338.11 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.