ONEOK NGL PIPELINE, LLC

Incident Narrative

AT APPROXIMATELY 11:26 ON 4/12/2018 ONEOK'S FIELD REPRESENTATIVE CALLED THE ONEOK PIPELINE CONTROL CENTER TO REPORT THE LANDOWNER AROUND ONEOK'S BLUE RIVER PUMP STATION HAD NOTIFIED HIM OF 'STEAM' COMING FROM THE ABOVEGROUND PIPING AT THE PUMP STATION. ONEOK'S FIELD REPRESENTATIVE ARRIVED ON SITE AT APPROXIMATELY 12:52 AND DETERMINED VAPORS WERE COMING FROM THE GASKET BETWEEN TWO FLANGES CONNECTED TO THE STATION DISCHARGE VALVE. THE PUMP STATION WAS SHUT DOWN AND ONEOK MECHANICS WERE CALLED TO RE-TORQUE THE BOLTS ON THE FLANGES. ONCE THE BOLTS WERE TIGHTENED TO THE TORQUE SPECIFICATIONS FOR THE FIBER GASKET THE PUMP STATION WAS RETURNED TO SERVICE AND NO LEAKS WERE IDENTIFIED. THIS PIPING HAD BEEN RECENTLY CHANGED OUT, DUE TO MAINTENANCE WORK AT THE FACILITY. ONEOK'S INVESTIGATION DETERMINED CONTRACTORS TIGHTENING THE BOLTS ON THE FLANGES, AFTER THE CHANGE OUT, UTILIZED THE TORQUEING REQUIREMENTS FOR METAL GASKETS INSTEAD OF TORQUEING REQUIREMENTS FOR THE FIBER GASKET. THIS RESULTED IN THE BOLTS BEING UNDER TIGHTENED. ONEOK REPRESENTATIVES MET WITH THE CONTRACTOR AND INSPECTOR THAT WORKED ON THE PROJECT AND EMPHASIZED THE IMPORTANCE OF INSURING THE CORRECT TORQUE SPECIFICATIONS ARE UTILIZED.