SPRINGFIELD, CITY UTILITIES OF

Incident Narrative

A NATURAL GAS CONSTRUCTION CREW WAS PERFORMING MAINTENANCE ON A DISTRIBUTION LINE BEHIND 5012 S CHARLESTON AVENUE. AT THAT LOCATION, A FLANGED CROSS FITTING CONNECTED SECTIONS OF GAS PIPELINE VIA VALVES TO THE NORTH, WEST, AND SOUTH IN AN EXPOSED VALVE CLUSTER PIT. IN PREPARATION FOR MAINTENANCE, THE VALVES TO EACH OF THE NORTH, WEST, AND SOUTH PIPELINES WERE CLOSED. GAS REMAINED IN THE NORTH AND WEST PIPELINE BUT HAD ALREADY BEEN PURGED FROM THE SOUTH PIPELINE. CREWS REMOVED THE FLANGED CROSS FITTING AND THE VALVE TO THE SOUTH. THOUGH THE VALVE TO THE NORTH WAS EXPOSED, IT WAS ATTACHED TO A SECTION OF PIPE CONNECTED TO THE UPSTREAM PIPELINE BY A COMPRESSION COUPLING THAT WAS UNDERGROUND AND NOT VISIBLE TO THE CREW. SHORTLY AFTER THE CREW REMOVED THE FLANGED CROSS FITTING, THEY HEARD A SOUND THEY RECOGNIZED TO BE A GAS LEAK, SO THEY BEGAN TO EVACUATE THE AREA AND CONTACTED EMERGENCY SERVICES. WITHIN APPROXIMATELY 5 MINUTES, THE BLOWING GAS IGNITED. GAS WAS THEN SHUT OFF FROM THE INCIDENT SITE AND THE FLAMES WERE EXTINGUISHED. EVENTUALLY IT WAS DISCOVERED THAT THE NORTH VALVE AND SECTION OF PIPE IT WAS ATTACHED TO HAD PULLED OUT OF THE COMPRESSION COUPLING CONNECTING IT WITH THE REST OF THE NORTH PIPELINE.