| 摘要 |
PURPOSE:To prevent the pressure fluctuation by providing a path for bypassing a pressure setting valve to the valve box while providing an electromagnetic valve in the proximity of the opening at the upper stream side of said path and a tapered section associated with a pressure regulating cone in the proximity of the opening at the downstream side. CONSTITUTION:A pressure setting valve 15 is operated to regulate the pressure at the downstream side near to the setting level. The pressure at the downstream side is detected by a pressure sensor 22 and compared with the setting level. If the detected output is lower than the setting level, the control section will produce a command for opening an electromagnetic valve 18 while if said output is higher than the setting level the control section will produce the command for closing the electromagnetic valve 18. Upon opening of the electromagnertic valve 18, the upper stream side pressure will function on the small diameter end face of a pressure regulating cone 19 which is choking the bypath 17 due to the downstream side pressure when the electromagnetic valve is closing, and the differential pressure between the downstream side pressure functioning on the large diameter end face will cause the slow driving of said cone 19 to the downstream side thus to open the bypath 17 slowly. |
