Kingston Model 215A Spring Loaded Check Valves are for non-return air or liquid applications. Body is of precision-machined cast brass with 25 percent glass-filled Teflon disc and stainless steel spring. These valves are designed for installation in horizontal pipe lines. Kingston Model 215A Spring Loaded Check Valves are suitable for lubricated and non-lubricated compressed air applications. Sizes 3/8″ and 1/2″ have a 1/8″ bleeder port, plugged. Maximum operating pressure 250 psi. Maximum operating temperature 200°F.