5500 Series Rev C Pilot Operated Pressure Relief Vent With Pipe Away; 3" Inlet Size; 4" Outlet Size, Mates With Standard ASME 150# Flanged Connections; Flat Face Aluminum Body, Aluminum Cover, Aluminum Seat Ring; 3.2 - 15.0 PSIG Pressure Spring Range; Fluorocarbon Elastomer (FKM) Actuator Diaphragm, Pilot Seals, And Seat; Standard: Internal Sensing,SST Pilot, Exhaust To Main Valve Outlet