Washington, DC, June 7, 2007 - The U.S. Chemical Safety Board today announced that initial testing of the propane tank recovered after a West Virginia convenience store explosion reveals 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.
The accident occurred on January 30, 2007, at The Little General Store in Ghent. On the day of the accident, investigators believe 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.
Testing also demonstrated that the fill valve, relief valve, and the tank itself do not leak. Experts and representatives of other interest parties observed the testing, which was conducted yesterday at a West Virginia contract laboratory. 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 yesterday, the CSB removed the liquid withdrawal valve from the tank. The CSB 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.
The CSB is an independent federal agency charged with investigating industrial chemical accidents. The agency's board members are appointed by the president and confirmed by the Senate. CSB investigations look into all aspects of chemical accidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.
The Board does not issue citations or fines but does make safety recommendations to plants, industry organizations, labor groups, and regulatory agencies such as OSHA and EPA. Visit our website, www.csb.gov.
For more information, contact Director of Public Affairs Dr. Daniel Horowitz, 202-261-7613, cell 202-441-6074.