A vacuum breaker valve is provided, including: a barrel member, a biasing assembly, a water stop gasket and a plate. The biasing assembly is abutted within the barrel member. The water stop gasket is disposed in the barrel member and abuts against the biasing assembly. The water stop gasket has a water stop portion which is deformable to close at least one air passage of the barrel member. The plate is located between the inlet end and the water stop gasket, and its engaging flange structure is blockable, in a direction toward the inlet end, by a shoulder portion of the barrel member. The biasing assembly normally drives the water stop portion of the water stop gasket apart from the at least one air passage to keep the at least one air passage non-closed.

A double check valve is provided that includes an in-line inlet check valve and an outlet check valve that cooperate to prevent back flow of fluid through the valve. The check valve also includes at least one vent that allows for fluid trapped within the check valve to drain, thereby preventing freezing of the check valve and hydrant to which it is interconnected. The check valve provided omits many superfluous components and thus is smaller and easier to install than check valves of the prior art.

Valve assemblies which comprise a valve housing; an inner valve element; an outer valve element spaced apart from the inner valve element; a valve stem on which both the inner valve element and the outer valve element are located; a portion of the valve stem between the inner valve element and the outer valve element is threaded; and a protective element located within the valve housing and covering the threaded portion of the valve stem.