Abstract: On June 26, 2001 an explosion occurred, injuring Employee #1 and Employee #2. The immediate cause of the accident was the closing and subsequent opening of the valve which failed. Due to it being a ball valve this resulted in the valve going from fully closed to fully open with just a quarter turn of the handle. As a result high pressure oxygen was allowed into a low pressure area quickly enough so that the resulting adiabatic heating and/or frictional heating generated enough heat to ignite the fluorocarbon coating on the ball stem. The resulting fire caused two sides and the front of the valve to explode as did the stainless steel tubing leading from the valve. The resulting flame front flowing out of the valve and flying debris from the explosion caused the injuries. The underlying cause of the accident was the improper design of the oxygen delivery manifold. The valve that failed was not designed for use in a high pressure oxygen system, it was not clearly established that it had been properly cleaned for use in an oxygen system and the delivery manifold had not been designed or reviewed by an engineer qualified to design oxygen delivery systems.