Reduced water hammer control valve

摘要

A control valve assembly for selectively controlling a flow of fluid through a fluid flow system is disclosed including a valve housing having a fluid inlet and a fluid outlet, a valve seat positioned about the fluid outlet and a sealing diaphragm for cooperating with the valve seat for selectively sealing off fluid communication between the fluid inlet and the fluid outlet. The diaphragm fluidically separates a pressure chamber from a control chamber within the housing. A central control orifice is formed in the diaphragm for fluidically communicating between the control chamber and the fluid outlet, an armature is reciprocally received in the housing for selectively sealing off fluid communication between the control chamber and the fluid outlet with at least two bleed orifices formed on the diaphragm which fluidically communicate between the pressure chamber and the control chamber. Extending into each of the bleed orifices is a metering element for controlling a flow of fluid between the pressure chamber and the control chamber for softening the return of the diaphragm to the closed position thereby eliminating compressive shock to the assembly. Preferably, the bleed orifices are diametrically opposed to one another and formed in a thinned region of the diaphragm which bridges a fixed outer periphery and a central region of the diaphragm.