NATURAL GAS PIPELINE CO OF AMERICA (KMI)

Incident Narrative

ON AUGUST 10, 2020 AT APPROXIMATELY 12:45 PM LOCAL TIME, NGPL GAS CONTROL CONTACTED LOCAL OPERATIONS OF A REPORT RECEIVED FROM A THIRD PARTY OF GAS VENTING NEAR VALVE V893 IN MADISON COUNTY, IOWA. AT 13:08 PM LOCAL TIME, NGPL OPERATIONS ARRIVED ON LOCATION AND FOUND THAT THE VALVE OPERATOR ON A CROSSOVER, ISOLATION VALVE WAS VENTING FROM A SMALL (1/8' DIAMETER) VENT ON THE VALVE ACTUATOR. AT THAT TIME, THE ESTIMATED QUANTITY GAS RELEASED WAS DETERMINED TO BE 39 MCF FROM THE INITIAL NOTIFICATION RECEIVED FROM THE PUBLIC BY GAS CONTROL AT 12:41 PM LOCAL TIME TO THE TIME OPERATION'S PERSONNEL ARRIVED ON SITE. AT THIS TIME, OPERATIONS BEGAN SERVICING THE VALVE TO STOP THE LEAK FROM THE ACTUATOR VENT. AT 17:00 PM LOCAL TIME, NGPL OPERATIONS REPORTED THAT ATTEMPTS TO STOP THE LEAK WITH APPLICATION OF VALVE GREASE WAS NOT COMPLETELY SUCCESSFUL AS THE LEAKING STOPPED BRIEFLY BUT CONTINUED INTERMITTENTLY. AT 17:10 PM LOCAL TIME, OPERATIONS DECIDES TO REMOVE THE VALVE FROM SERVICE AND ESTIMATES THE COST WOULD BE GREATER THAN $50,000. AT 17:15 PM LOCAL TIME, THE NATIONAL RESPONSE CENTER WAS NOTIFIED (NRC REPORT NO. 1284223). THE 48-HOUR UPDATE COMMUNICATING NO SIGNIFICANT CHANGES WAS COMPLETED AT 16:25 PM LOCAL TIME ON 08/11/2020 (NRC REPORT NO. 1284327). INVESTIGATION: RESULTS OF THE INVESTIGATION SHOWED THAT THE VALVE X893E2, 20' PLUG VALVE INSTALLED IN 1957, PROVIDES CROSSOVER ISOLATION BETWEEN THE #2 AND #3 AMARILLO MAINLINES. APPLICATION OF GREASE DOWN THE CENTER GREASE FITTING FORCES THE STEM PACKING AROUND THE VALVE STEM, SEALING IT, AND PREVENTING GAS FROM TRAVELING UP THE VALVE STEM AND EXITING THE ACTUATOR VENT. AS DISCUSSED ABOVE, OPERATIONS ATTEMPTED TO STOP THE LEAK FROM THE ACTUATOR VENT BY SERVICING THE VALVE WITH GREASE; HOWEVER, THIS ACTION DID NOT COMPLETELY STOP THE LEAK. AT THAT TIME (APPROXIMATELY 17:10 PM LOCAL TIME), NGPL OPERATIONS DECIDED TO REMOVE THE VALVE AND ASSOCIATED CROSSOVER PIPING FROM SERVICE TO AVOID HAVING TO TAKE BOTH THE NGPL AMARILLO MAINLINES NO. 2 AND NO. 3 OUT OF SERVICE, ADVERSELY AFFECTING NATURAL GAS DELIVERIES TO CUSTOMERS DOWNSTREAM FROM THE LOCATION. THE INVESTIGATION DETERMINED THAT ONLY A SMALL AMOUNT OF HARD AND INEFFECTIVE STEM PACKING REMAINED IN THE PLUG ASSEMBLY. THE IMMEDIATE/DIRECT CAUSE OF THE EVENT WAS DETERMINED TO BE THE STEM PACKING IN THE SERVICE LINE WAS DEPLETED AND NO LONGER SERVICEABLE. THE BASIC/ROOT CAUSES INCLUDED THE AGE AND SERVICEABILITY OF THE STEM PACKING. CORRECTIVE ACTIONS: REVIEW VALVE SERVICING AND MAINTENANCE PROCEDURES WITH ALL NGPL OPERATORS INVOLVED IN VALVE SERVICING/MAINTENANCE FOR THESE TYPES OF VALVES TO LIMIT VALVE-PACKING LEAKAGE GOING FORWARD. NGPL REMOVED THE VALVE FROM SERVICE AS DESCRIBED ABOVE.