Patent ID: 6079437
Filing Date: 2000-06-27
Classification: F16K,Y10T

Abstract:
A diaphragm valve, comprising:a valve housing having an inlet passage, an outlet passage, a primary valve seat between the inlet passage and the outlet passage, a lower inlet chamber below the primary valve seat, an upper pressure control chamber above the primary valve seat, and a neck forming a bore that communicates with the upper pressure control chamber;a pilot valve operatively associated with the upper pressure control chamber for selectively venting pressurized water therefrom;a diaphragm assembly mounted inside the valve housing and having a seal normally engaged with the primary valve seat to seal the inlet passage from the outlet passage, the diaphragm assembly being moveable in a first direction to disengage the seal from the primary valve seat upon release of a sufficient amount of pressurized water from the upper pressure control chamber, the diaphragm assembly including means for metering water from the lower inlet chamber through the diaphragm assembly into the upper pressure control chamber; anda flow control stem extending from an upper side of the diaphragm assembly and through the bore, the flow control stem being moveable from an extended position in which it seals the bore to a retracted position in which air trapped in the upper pressure control chamber can be bled out through the bore.