Anti-syphon flow control valve

Claim 1

A flow control valve having a housing including an inlet and an outlet, a liquid valve means between the inlet and the outlet, said liquid valve means comprising a valve seat and a valve plug means for engaging said valve seat, a pressure responsive diaphragm mounted in said housing above said plug means, said plug means being connected to said pressure responsive diaphragm for movement therewith, said plug means being moved between an open and closed position by forces acting on opposite sides of said pressure responsive diaphragm, a first chamber being formed above said pressure responsive diaphragm with said housing, a second chamber being formed below said pressure responsive diaphragm with said housing, a diaphragm support ring being positioned in said second chamber to support said diaphragm when said liquid valve means has its valve plug means in its closed position, said valve seat opening into said second chamber, a first conduit means connecting said valve seat to said inlet, a second conduit means connecting said second chamber to said outlet, opening means connecting the exterior of said housing to said second chamber, anti-syphon valve means cooperating with said opening means to connect the exterior of said housing to said second chamber and valve seat when a suction occurs in said inlet, said anti-syphon valve means having valve flap means extending downwardly into said second chamber, said flap means cooperating with said opening means in said housing to normally close said opening means, said flap means being pulled inwardly into said second chamber when a suction occurs, said flap means contacting the first conduit means in their innermost position to block a reverse flow from the outlet to the inlet, said diaphragm support ring being position on projections extending inwardly from said housing, each projection extending between a pair of adjacent flaps, said flaps having notches to receive said projections, said flap notches engaging the sides of said cooperating projections when said flaps have been pulled inwardly.