摘要 |
<p>A solenoid-operated pilot valve of the diaphragm type which includes an assembly for controlling the flow of liquid through the valve. The valve has particular although not exclusive utility for irrigation purposes. The valve includes a diaphragm chamber into which fluid is introduced to establish a fluid pressure which normally forces a diaphragm against an annular seat in the valve to assist a spring in maintaining the valve in a closed condition. A stationary bleed tube is provided which extends through the diaphragm into the diaphragm chamber. A solenoid is mounted on the cap of the valve, and the plunger of the solenoid normally closes off the upper end of the bleed tube. However, when the solenoid energized, the plunger is withdrawn and the bleed tube opens and drains the diaphragm chamber sufficiently to reduce the pressure therein to a point at which the diaphragm is forced off its seat by upstream fluid pressure, and the valve is opened. A flow adjustment mechanism is mounted in the cap which includes an axially movable gear nut functioning as an adjustable stop for the diaphragm to control the flow of liquid through the valve.</p> |