Abstract: On January 15, 2007, Employee #1 was working with two coworkers to start a steam-driven back up pump for crude circulation. Employee #1 was starting the pump to circulate diesel through the system. Employee #1 placed the pump in the proper configuration and then proceeded to open the steam valve to start the pump. Within seconds of starting the pump, a "pop" sound was heard and a stream of diesel from adjacent piping ensued. The stream of diesel was approximately 15 ft high. Employee #1 and the two helpers were soaked in diesel. All three employees ran in different direction to get away from the pressurized diesel stream. The diesel caught fire and burned for hours. The causal factor for the accident was a missing seat in the 4-in. gate valve. Sulfur containing material migrated past this Valve. The pipe beyond the Valve was not meant for a sulfur containing material and corroded to exhaustion. Employee #1 sustained second-degree burns to the back of his neck as a result of a release of diesel and its subsequent ignition. Employee #1 was hospitalized.