Abstract: A backflow prevention test assembly for a backflow preventer has a test valve in fluid communication with a conduit of the backflow preventer and a test kit. The test valve has a body defining an axial bore, and a piston defining a test conduit is disposed within the axial bore for movement between a first position permitting test flow through the test conduit and a second position resisting test flow. The piston is biased toward the second position. The test kit includes a test apparatus and a fitting for attachment upon the test valve body in sealing engagement. The fitting defines a displacement surface for engagement, after sealing engagement of the seal with the test valve, with an opposed surface of the piston to urge the piston toward its first position, thereby to establish fluid communication between the test apparatus and a region of the backflow preventer conduit. A method of testing fluid within the flow conduit of the backflow preventer is also described.

Abstract: A pressure-type vacuum breaker for use in a fluid flow line has a housing defining a central bore and an inlet, an outlet and a discharge vent. A piston assembly disposed within the central bore is movable within the bore between first and second positions. In the first position of the piston assembly, the inlet is closed, the discharge vent is open and the outlet is in communication with the discharge vent and the atmosphere. In the second position of the piston assembly, the discharge vent is closed, the inlet is open and the outlet is in communication with the inlet, thereby to permit liquid flow between inlet and outlet. The position of the piston assembly is in predetermined response to pressure of liquid at the inlet.