Model 1049 Pilot Operated Vent Valve; Carbon Steel Body With Flame Screen; 3" Inlet X 4" Outlet ASME Class 150# Rf Flanges; Fkm Soft Seats; Option 1: With Internal Sensing, SST Pilot Filter Element, Pilot;Exhaust Tubed To Main Valve Outlet; Viton (Fkm) Actuator Diaphragm; 3.2 - 14.0 PSIG; Rev Level A