Abstract: In order to prevent contamination of a fluid source and to ensure drainage of a sill cock or the like, a detachable check valve back flow preventer for installation between a fluid inlet line and a fluid outlet line is provided. A housing with means for fastening the device to a fluid inlet line at one end of the housing and for connecting a fluid outlet line at the other end of the housing is provided. The housing has a central cavity within the housing. An inlet line drain valve is located within the housing between the central cavity and the fluid inlet line to provide for the drainage of fluid from the fluid inlet line to the fluid outlet line end of the housing when the fluid outlet line is not connected to the back flow preventer. A second valve is located within the housing between the central cavity and the fluid inlet line to control flow of fluids between the fluid inlet line and the central cavity.

Abstract: A self-draining hose connection vacuum breaker and backflow preventer having a flexible annular diaphragm and a coacting seat disc movable relative thereto which, together, function to prevent backflow through the device and with the annular diaphragm coacting with atmospheric vents to provide a vacuum break and fluid drain. A movable piston has two different positions, dependent upon whether or not a hose is connected to the device, with the piston mounting the seat disc for movement therewith and relative thereto whereby the seat disc and annular diaphragm coact to prevent backflow when a hose is attached to the device, but the seat disc is positioned to permit flow through a central opening of the annular diaphragm when a hose is removed from the device to prevent trapped water in a source valve, such as a faucet or the like, which could result in either pipe and/or valve rupture resulting from freezing or retention of stagnant water which could result in bacterial growth.

Abstract: A thermal element having a tubular casing with an open end, a volume of heat-responsive, expandable wax positioned in said casing at a distance from the open end thereof, a spherical resilient seal member compressively positioned in the casing adjacent said wax, a motion-transmitting pin extended between the seal member and the open end of the casing and having a relatively soft washer affixed thereto for engagement against the seal member and with at least one peripheral notch in the washer permitting flow of liquid thereacross.

Abstract: An improved relief valve of the type responsive to a predetermined thermal and/or pressure condition. The valve includes a valve body having an inlet, an outlet, an internal passage interconnecting the two, a valve seat about the passage and an opening coaxial with the valve seat, a poppet valve within the body, including a stem extending towards the opening and having a pressure responsive surface directed toward the inlet side of the valve seat, a closure disposed within the opening and having a central aperture slidably and sealingly receiving the stem, the closure being formed of a thin, relatively ductile material and having an outwardly extending lip frictionally captured by the body about the opening and sealingly engaging the body thereabout, the closure further including an annular convex ridge inwardly of the lip and within the body and a central pedestal directed oppositely of the ridge.