Vp50 series pneumatic proportional valve, used in environmental protection, biological industry, agriculture, mining, tr

Working principle

Proportional pressure control valves and direct-acting plungers are in the suction process, at this time the intake valve spring is compressed, the valve plate moves downward, so the intake valve opens and inhales gas. When the piston travels back, that is, when it moves upward from the bottom dead center, the suction valve begins to close, that is, the valve plate moves upward under the action of its spring force to the close position of the valve seat.When the output pressure of the proportional pressure control valve is higher or the diameter is larger, the pressure regulating spring is used to directly adjust the pressure, then the spring stiffness is inevitably too large, and the output pressure fluctuates greatly when the flow rate changes, and the structural size of the valve will also increase. In order to overcome these shortcomings, pilot operated pressure reducing valves can be used. The working principle of the pilot type pressure reducing valve is basically the same as that of the direct acting type. The pressure regulating gas used in the pilot pressure reducing valve is supplied by a small direct acting pressure reducing valve. If the small direct-acting pressure reducing valve is installed inside the valve body, it is called the internal pilot pressure reducing valve; If the small direct acting pressure reducing valve is installed outside the main body, it is called an external pilot pressure reducing valve. Compared with the direct-acting pressure reducing valve, the valve has added a nozzle baffle amplifier link composed of a nozzle 4, a baffle fixed orifice 9 and an air chamber B.When the distance between the nozzle and the baffle changes slightly, the pressure in chamber B will change significantly, resulting in a large displacement of the diaphragm 10, to control the up and down movement of the valve core 6, so that the intake valve port 8 is opened or closed, and the sensitivity of the control of the valve core is improved, that is, the pressure regulation accuracy is improved.