| 摘要 |
A digitally controllable valve has a main valve member mounted on a diaphragm for movement sealing and exposing a main valve seat. A flow restriction on the main valve member varies the flow rate as a function of displacement of the main valve member from the main valve seat. Pressure in a reservoir above the diaphragm is controlled by two pilot valves respectively connected to the inlet and outlet ports of the main valve, one of which has fluid passageway with a larger minimum cross sectional area than the other. Both pilots communicate with the reservoir through a single common bleed opening which has an area less than the minimum cross sectional areas of pilot valve flow passageways. |
