MIDCOAST PIPELINES (EAST TEXAS), L.P.

Incident Narrative

* INADEQUATE WARNING SYSTEM * TEMPERATURE EXTREMES AIR CONDITIONING FAILED WHICH CAUSED ELEVATED TEMPERATURES IN THE MCC. THE ELEVATED TEMPERATURES LEAD THE SHUTDOWN OF THE UPS. THE SHUTDOWN OF THE UPS (LOSS OF POWER) TRIGGERED THE ESD OF THE FACILITY. THE ELEVATED TEMPERATURES DID TRIGGER AN ALARM, BUT THIS ALARM WAS INACCURATELY LABELED IN THE MOST PROMINENT LOCATION. THE ALARM TAG WAS CORRECT BUT THE DESCRIPTION OF ALARM WAS WRONG. THIS GAVE OPERATIONS THE FALSE IMPRESSION OF A GENERATOR ISSUE WHICH WAS FOLLOWED UP ON AN NO ISSUES WERE FOUND. * INADEQUATE ENGINEERING * INADEQUATE OR IMPROPER CONTROLS DUE THE ESD VALVE SEQUENCE DESIGN, THE INLET AND STATION VALVES ACTUATED CLOSED AND THE BLOWDOWN VALVES ACTUATED OPEN. HOWEVER, THE OUTLET OUTLET VALVE (0201) FAILED TO SEAL CLOSED ALLOWING THE BLOWDOWN VALVES TO NOT ONLY DE-PRESSURE THE STATION BUT CONTINUE TO BLOWDOWN THE PIPELINE SYSTEM THAT SHOULD HAVE BEEN ISOLATED BY DESIGN. ACTIONS TAKEN TO DATE: 1) VALVE CONTRACTOR CHANGED OUT HYDRAULIC FLUID, ADJUSTED PRESSURES IN VALVE CHAMBERS, 2) CHANGED DESCRIPTION ON THE ALARM TAG IN SOFTWARE, 3) AS MENTION ABOVE THE ESD VALVE CLOSURE SEQUENCE HAS BEEN MODIFIED TO PRESENT BLOW DOWN VALVE FROM OPENING UNTIL INLET AND OUTLET VALVES ARE COMPLETELY CLOSED ON STATION. THIS SETUP WAS TESTED AND DOCUMENTED AS WORKING PROPERLY.