Pressure relief system

Claim 1

In combination with a pressurized vapor containment, means for heating the vapor, said containment being free to move in response to thermal expansion and contraction, a pressure relief valve connected to said containment to release vapor therefrom, a vent pipe connected to said valve to receive the released vapor, a fixed exhaust pipe communicating with said vent pipe to dispose of the vapor being discharged therefrom, and a fixed annular drip pan surrounding the vent pipe and communicating with the exhaust pipe to collect condensate drippings, the pan having an opening sized to allow for relative vent pipe movement occasioned by containment movement, the drip pan opening being covered by upper and lower annular plates surrounding the vent pipe, the lower plate being slidably interposed between said drip pan and upper plate, the lower plate having an opening sized to allow for an initial movement of the vent pipe, and said lower plate being movable to accommodate the remainder of said vent pipe movement.