Plast-O-Matic Valves.Inc. Polished Thermoplastic Air Release Valve, Packaging Type : Carton

Series ARV is a normally-open valve. Until your system is pressurized, the valve is simply open, and the air is present. As pressure builds within the system, unwanted air is forced to the highest point in the system, i.e., the normally-open Air Release Valve. When pressure within the system exceeds atmospheric pressure, the air is expelled. As liquid rises, the poppet becomes buoyant and eventually closes. (Note minimum specific gravity of liquid must be .9 or higher). It is possible that trace amounts of air will remain in the system, depending on the rapidity with which the valve closes. It is also likely that some trace amounts of process liquid will be emitted. At a system pressure of 10 psi (with EPDM elastomer), the poppet will seal the bubble-tight against the orifice. When pressure and liquid level drop, the valve will automatically re-open.