The Difference Between The Pneumatic Control Valve and the Self-Operated Control Valve

control valve

The self-operated regulating valve can not only control the downstream pressure but also control the upstream pressure. The self-operated regulating valve is actually a pure proportional regulating system with residual error. The main function of the self-operated regulating valve is to meet the upstream or set pressure value, and there is no great requirement for the flow rate. But for the regulating valve, the direct control is the flow rate. The biggest difference between these two kinds of valves is that the control valve needs external energy (such as a power supply or gas source) as the driving force, and the relative position of the interceptor in the valve is changed by controlling the instrument signal, so as to change the flow rate. The self-operated regulating valve does not need foreign energy or external control instrument signal. The pressure adjustment can be realized only by the pressure or temperature signal of the medium itself.

So we can distinguish a pneumatic control valve from a self-operated control valve in three aspects.

a. Adjustment accuracy

b. Application conditions

c. Installation and Design