Electrical proportional valve is based on the size of the control signal to adjust the valve core area. So as to achieve the adjustment of pressure size process objectives and requirements. Control of flow by electric proportional valves can be divided into two types. One is switch control, the other is continuous control, servo valve is different from other valves, its energy loss is greater, because it needs a certain flow to maintain the pre-stage control oil circuit work. One is switch control: either fully open or fully closed, the flow is either maximum or minimum, there is no intermediate state, such as ordinary electromagnetic through valve, electromagnetic reversing valve, electro-hydraulic reversing valve. The other is continuous control: the valve port can be opened according to the need to open any degree, thus controlling the size of the flow through the valve, such as manual control, such as throttle valve, electronic control, such as proportional valve, servo valve. Electric proportional valve through electric signal control gas pressure, gas pressure can achieve continuous, stepless regulation, remote control and program control, for the need for continuous or stepless regulation of gas pressure, especially suitable for electrical proportional valve.

Electric proportional valve advantages:
1) Electric proportional mode to realize stepless control of outlet pressure.
2) Can realize remote control and program control.
3) Compared with intermittent control, the system is simplified and the components are greatly reduced.
4) Compared with the hydraulic proportional valve, small volume, light weight, compact structure, lightweight, low cost, but the response speed is much slower than the hydraulic system, and more sensitive to load changes.
5) Low power consumption: less than 4W (communication form).
6) There will be no fire and no environmental pollution. The effect of temperature change is small.