| 摘要 |
PURPOSE:To control a degree of opening of a valve by itself in accordance with a flow rate, by providing not only a main flow formed by an inlet, a valve body and an outlet, but also a by-pass communicating to the outlet through the inlet, a valve body back part, and a controlling pilot valve, and controlling by a reducing element. CONSTITUTION:Not only a main flow flowing to an outlet 3 through an inner valve 9 and a cage 5 from an inlet 2, but also a by-pass passing through a pressure conducting pipe 18, a pipe 41, valve body back parts 16a, 16b, a pipe 43, a controlling pilot valve 20, a pipe 45 and a pressure conducting pipe 19 are formed. The controlling pilot valve 20 is provided with an inner valve 22 freely slidable in the axial direction, in the inside of a cylindrical body 21 having an inlet 21a and an outlet 21b. Pressure of the outlet 21b is fed back to a diaphragm 24. A working point setting mechanism 26 of the inner valve 22 sets a position by press-contacting of a lever 33 and a conical part 31 of a shaft 14 of the inner valve 9. Pressure of the valve body back part is controlled by controlling needle valves 40, 42 and 44. In this way, the inner valve 9 is operated up and down so that pressure of the outlet side 3 is varied in accordance with the quantity of water to be used, which is suitable for reducing the water leakage of water service. |
