MODEL 1049 PILOT OPERATED VENT VALVE STAINLESS STEEL BODY; 3" INLET X 4" OUTLET ASME CLASS 150# RF FLANGES; EPDM SOFT SEATS; INTERNAL SENSING, SST PILOT FILTER ELEMENT, PILOT EXHAUST TUBED TO MAIN VALVE OUTLET, WITH BACKFLOW PREVENTER; EPDM ACTUATOR DIAPHRAGM; 18.1" - 36.0" WC; REV LEVEL A; PER SPQ NUMBER 54416 WITH FLAME SCREEN;