Patent ID: 7293576

Claim:
A single-piece manifold for a fire sprinkler system comprising: a body defining a main conduit therethrough in communication with an inlet for connecting the single-piece manifold to a supply of water and an outlet for connecting the single-piece manifold to the fire sprinkler system, a first check valve and a second check valve within said main conduit for preventing or permitting fluid flow communication through said main conduit, a first pressure zone defined between said inlet and said first check valve and a second pressure zone defined between said first check valve and said second check valve, and a valve member in communication with said first pressure zone and said second pressure zone for preventing water from said second pressure zone from flowing back into said first pressure zone said valve member including: a first conduit in fluid flow communication with said first pressure zone; a second conduit in fluid flow communication with said second pressure zone and an outlet; a diaphragm which in a closed position prevents fluid flow communication in said second conduit at a point between said second pressure zone and said outlet; and a spring having a spring force, said spring biasing said diaphragm in said closed position; wherein, if pressure in said second pressure zone is greater than the combination of pressure in said first pressure zone and said spring force, said diaphragm is moved to an open position.