Pneumatic control valve overview and working principle

1. Overview

Pneumatic control valve is a kind of automatic control equipment, widely used in various industrial fields. It is driven by a pneumatic actuator to control the flow, pressure or temperature of fluid media such as gas and liquid. Pneumatic control valve has the characteristics of stable action, fast response speed and easy maintenance, so it is widely used in the automatic control system of petroleum, chemical, electric power, metallurgy and other industries.

2. working principle

The working principle of the pneumatic control valve is mainly based on the regulation principle in the control theory. Its core components include two parts of the actuator and the valve body.

1. Actuator: pneumatic actuator is the power source of pneumatic control valve, usually using compressed air as power. When the input air pressure changes, the actuator will drive the valve stem to move up and down or rotate.

2. Valve body: The valve body is the core part of the pneumatic control valve, with one or more valves inside to control the circulation of fluid. The position of the valve flap is precisely controlled by the actuator to achieve flow, pressure or temperature control.

The specific work process is as follows:

When the control system sends a signal, the pneumatic actuator receives the corresponding air pressure signal and drives the valve flap to open or close. When the valve position changes, the flow area of the fluid will change, thereby changing the flow, pressure or temperature. The actual parameters are fed back to the control system through the sensor, and the control system sends the corresponding signal to adjust the position of the valve flap, so that the actual parameters reach the set value.

In addition, the pneumatic control valve can also be equipped with positioners, pressure reducing valves and other accessories to improve its control accuracy and stability. The positioner can accurately control the position of the valve flap, and the pressure reducing valve can stabilize the input air pressure to ensure the stable work of the pneumatic actuator.

In short, the pneumatic control valve through the pneumatic actuator drive valve action, to achieve the fluid medium flow, pressure or temperature control. Its working principle is simple and clear, stable and reliable, widely used in various industrial fields of automation control system. In practical applications, it is also necessary to select the appropriate model and configuration according to specific needs to ensure the stable operation of the system.