Abstract: Three employees were using a liquid propane torch to heat a pipe just below a check valve. They were using the torch to liquefy sulfur in the pipe. A pump on the system pumped the liquid sulfur to a burner. The employees were severely burned when a steam-jacketed molten-sulfur valve ruptured and sprayed steam and burning molten sulfur across their chests, faces, and upper extremities. They were hospitalized for their injuries. The pump, which was equipped with an internal hydraulic relief valve set to activate at 831 pascals, was malfunctioning before the incident. In addition, the relief valve on the pump was not designed to protect the rest of the system; the valves and associated piping had a pressure rating of only 50 pascals and did not have any type of relief valve. Fire-resistant jackets were provided to but not worn by the employees.