5500 Series Rev D Pilot Operated Pressure Relief Vent With Pipe Away; Mates With ASME 150 Flange Connection; 2" Inlet Size; 2" Outlet Size; Carbon Steel Body, 316 Stainless Steel Bolt-In Seat Ring; Fluorocarbon Elastomer (FKM) Actuator Diaphragm, Pilot Seat, And Pallet Diaphragm; 2.1" - 12.0" wc Pressure Spring Range; Opt-7: Internal Sensing With Pilot Exhaust To Atmosphere, Backflow Preventer, And Rotometer To Purge Pilot Sense Line