US Patent 7543653 Diaphragm latch valve

A valve for fire suppression sprinkler systems is disclosed. The valve has a chamber with an inlet and an outlet. A closure member, positioned within the chamber, is movable to close and open the inlet. A latch engages the closure member to hold it in the closed position. The latch also engages a deformable diaphragm. The diaphragm deforms in response to pressure applied to it and allows the latch to move between a latched position engaged with the closure member and an unlatched position away from the closure member. When the diaphragm is depressurized it allows the latch to move and disengage from the closure member, which opens under fluid pressure from the inlet and allows fluid to flow through the valve.