PEOPLES NATURAL GAS COMPANY LLC

Incident Narrative

ON FEBRUARY 12, 2013 AT 1:25 PM A PNG CREW WAS IN THE PROCESS OF REPAIRING A FLANGE LEAK AT THE GASKET SURFACE OF A 12 INCH GATE VALVE LOCATED IN A CEMENT PIT AT THE INTERSECTION OF 50TH STREET AND BROAD AVENUE. AFTER TIGHTENING A SERIES OF BOLTS ON THE FLANGE, THE CREW HEARD A POPPING SOUND AND OBSERVED A CRACK IN THE VALVE BODY. THIS MAIN LINE VALVE IS LOCATED NEAR THE SOLE SOURCE OF SUPPLY FOR THE ENTIRE ALTOONA SYSTEM, SERVING APPROXIMATELY 30,000 CUSTOMERS AND OPERATES WITH 150 POUND MAOP. IMMEDIATE RESPONSE INCLUDED VENTING, CONTINUOUS SURVEY OF SURROUNDING AREA IN COOPERATION WITH 911 RESPONDERS, GATHERING MATERIALS, PNG MANPOWER, AND OUTSIDE CONTRACTOR SUPPORT TO INSTALL A BYPASS AND SET 20 INCH AND 12 INCH STOPPLES. A BYPASS WAS INSTALLED AND STOPPLE EQUIPMENT WAS SET, ACHIEVING SHUT DOWN OF BLOWING GAS ON FEBRUARY 14, 2013 AT 12:18 PM. FINAL REPAIRS INCLUDED REPLACEMENT OF CRACKED VALVE WITH 12 INCH FLANGED SPOOL PIECE. THE VALVE WAS SENT TO DET NORSKE VERITAS FOR METALLURGICAL ANALYSIS REVEALING COMPOSITION OF VALVE TO BE CAST IRON. FURTHER TESTING CONCLUDED THAT FAILURE WAS CAUSED BY OVERSTRESSING, ORIGINATING AT THE EXTERNAL SURFACE OF THE VALVE. PEOPLES NATURAL GAS IS IDENTIFYING AND INSTALLING WARNING TAGS TO ALL VALVES MANUFACTURED BY DARLING, VALVES OF KNOWN CAST IRON MATERIAL, AND THOSE OF UNKNOWN COMPOSITION. THESE WARNING DEVICES ARE TO REMIND OPERATORS TO EXERCISE CAUTION WHEN OPERATING OR REPAIRING CAST IRON VALVES OR VALVES OF UNKNOWN MATERIAL ORIGIN. PART F -DRUG AND ALCOHOL TESTING INFORMATION WAS REVISED IN FINAL REPORT TO REFLECT NO EMPLOYEES TESTED. PNG DID SEND TWO EMPLOYEES FOR POST INCIDENT TESTING, COMPLETING THE DRUG ASPECT WITHIN THE PRESCRIBED TIMEFRAME, BUT MISSED THE TIME DEADLINE ON THE ALCOHOL TEST REQUIREMENT. ADDITIONAL TRAINING ON VALVE REPAIR AND POST INCIDENT PROCEDURES WILL BE PERFORMED.