The regulating valve is the most widely used type of final control element. Other final control elements include metering pump, regulating damper and louver damper (a variant of butterfly valve), variable pitch fan blade, current regulator and motor positioning device different from the valve. Although the regulating valve is widely used, other units in the regulating system probably do not have as little maintenance work as it does. In many systems, the operating conditions of the control valve, such as temperature, pressure, corrosion and pollution, are more serious than other components. However, when it controls the flow of process fluid, it must operate satisfactorily and require minimal maintenance.

The regulating valve is composed of an electric actuator or a pneumatic actuator and a regulating valve. The regulating valve is generally divided into two types: straight through single seat regulating valve and straight through double seat regulating valve. The latter has the characteristics of large flow capacity, small imbalance and stable operation, so it is usually especially suitable for the occasions with large flow, high pressure drop and little leakage.