Overview of Self actuated control valve

Overview of Self actuated control valve

Self actuated control valve, also known as self operated control valve, is a regulating valve that relies on the pressure and temperature of the medium flowing through the valve as energy to drive the valve to work automatically without external power supply and secondary instrument. Self actuated control valve is mainly divided into Self actuated pressure control valve, self operated differential pressure regulating valve, self operated temperature regulating valve and self operated flow regulating valve.

Effect

Self operated control valves use the feedback signals (pressure, differential pressure and temperature) at the valve output end to be transmitted to the actuator through the signal pipe to drive the valve disc and change the opening of the valve, so as to adjust the pressure, flow and temperature.

Advantage

Self actuated control valve is a new type of regulating valve. Compared with manual control valve, its advantage is that it can be adjusted automatically; Compared with the electric control valve, its advantage is that it does not need external power. The application practice shows that in closed water circulation systems (such as hot water heating system and air conditioning chilled water system), the correct use of this valve can easily realize the flow distribution of the system; It can realize the dynamic balance of the system; It can greatly simplify the debugging of the system; It can stabilize the working state of the pump, etc.

classification

Self operated control valve is divided into direct action type and indirect action type.

Folding direct action

The direct acting regulating valve, also known as the spring-loaded regulating valve, has elastic components in its structure, such as spring, bellows, bellows type temperature packet, etc., using the principle of balance between elastic force and feedback signal.

Folding indirect action

The indirect acting regulating valve adds a commander (pilot valve), which plays the role of amplifying the feedback signal, and then drives the movement of the main valve disc through the actuator to change the valve opening.

If it is a pressure regulating valve, the feedback signal is the outlet pressure of the valve, which is introduced into the actuator through the signal pipe.

If it is a flow regulating valve, there is an orifice plate (or other resistance device) at the outlet of the valve, and the differential pressure signal is taken out from both ends of the orifice plate and introduced into the actuator.

If it is a temperature regulating valve, there is a temperature sensor (or temperature packet) at the outlet of the valve, which drives the actuator through the thermal expansion and cold contraction of the medium in the temperature sensor.