Self-reliance type pneumatic control valve has a direct effect and indirect effect of two kinds

Self-reliance type pneumatic control valve is divided into direct effect and indirect effect type two kinds. Direct action type pneumatic control valve is also known as the spring load type pneumatic control valve, its have elastic element structure: such as spring, bellows, bellows type of bulb, etc. , the principle of balance with the elastic force feedback signal. Indirect role type pneumatic control valve, added a command ( Pilot valve) It play a role of feedback signal amplification and then through the actuator, drive the main valve disc movement to achieve the purpose of the change of valve opening. If be pneumatic pressure regulator, feedback signal is the valve outlet pressure, by introducing actuator signal pipe. If the flow pneumatic control valve, the valve outlet has an orifice ( Or other resistance devices) Introduced by orifice plate ends out differential pressure signal actuators. If the temperature of pneumatic control valve, valve of the export is the temperature sensor ( Temperature or package) Through the temperature sensor in medium heat bilges cold shrink drive actuators.