Safety

CSB: Faulty Valve Likely Source of Propane Blast

June 11, 2007

After initial testing of the propane tank that was recovered after an explosion at a West Virginia convenience store, the Chemical Safety and Hazard Investigation Board (CSB) has concluded that the liquid withdrawal valve on the tank malfunctions and leaks and was the likely source of the large propane release that exploded, killing four people and injuring five others.

Josh Cable

The accident occurred Jan. 30 at The Little General Store in Ghent, W.Va. On the day of the accident, CSB investigators believe that personnel involved in the installation of a new propane tank at the store removed a metal screw cap on the liquid withdrawal valve, in preparation for removing propane from the old tank. When operating normally, a spring-loaded actuator prevents the valve from leaking when the screw cap is removed.

According to CSB, testing also demonstrated that the fill valve, relief valve and the tank itself do not leak. The nondestructive testing was conducted by filling the tank with gas and observing the rate of leakage at a range of pressures.

Following the testing, CSB removed the liquid withdrawal valve from the tank. CSB said it will be developing additional testing protocols to determine the cause of the valve malfunction. Further testing of the valve will occur in the next few months after the protocols are developed.