Single-piece manifold with reduced pressure arrangement
View Patent ↗A single-piece manifold comprising a body having an inlet in communication with a water supply and an outlet that communicates with a sprinkler system having a main conduit adapted for fluid flow between the inlet and the outlet is disclosed. The body includes a main valve that provides a means of manually shutting off communication with the water supply and first and second check valves positioned across the main conduit for preventing fluid flow therethrough until the sprinkler system is activated. The single-piece manifold has a reduced pressure arrangement comprising a valve member that vents water that may build up between the first and second check valves in order to prevent the back flow of contaminated water from the sprinkler system to the water supply.
1. 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.
2. The single-piece manifold of claim 1 , further including a vent passageway in fluid flow communication with said main conduit.
3. The single-piece manifold of claim 1 , wherein said first and second check valves being pivotable between a closed position wherein fluid flow is prevented and an open position wherein fluid flow is permitted.
4. The single-piece manifold of claim 1 , further comprising a main valve in said main conduit movable between an open position in which water may enter said body and a closed position in which water is prevented from passing through said body.
5. The single-piece manifold of claim 1 , further including a fire alarm means responsive to the movement of said second check valve and a means for preventing the sounding of a false alarm.
6. The single-piece manifold of claim 5 , wherein said false alarm means includes a flow switch arrangement which sounds a false alarm when activated, a plunger which is slidably received in a sleeve to be moved into and out of close proximity with said flow switch arrangement to activate said flow switch arrangement by a cam surface of said second check valve, wherein when said second check valve is moved to an open position, said cam surface forces said plunger into contact with said flow switch arrangement to sound said fire alarm.