The working principle and selection application of pneumatic diaphragm control valve
Pneumatic diaphragm control valve is an important industrial process control instrument, which is widely used in fluid control systems in various industrial fields. It is composed of a combination of pneumatic actuator and diaphragm control valve, which has the characteristics of simple structure, reliable action, high adjustment accuracy, large flow, light weight and good sealing performance. This article will introduce the working principle, selection and application of pneumatic diaphragm control valve in detail.
1. The working principle of pneumatic diaphragm regulating valve
The working principle of the pneumatic diaphragm regulating valve is to drive the diaphragm through the pneumatic actuator, so that the diaphragm produces displacement, so as to change the gap between the diaphragm and the valve body, and realize the adjustment of parameters such as flow, pressure and liquid level of the fluid medium. The pneumatic actuator usually uses compressed air as the power source, and adjusts the displacement of the diaphragm by controlling the opening of the pneumatic signal, and then changes the flow area of the regulating valve to realize the regulation of the fluid.
The structure of the pneumatic diaphragm regulating valve mainly includes the valve body, diaphragm, valve core, valve seat, guide sleeve, sealing ring and other parts. Among them, the diaphragm is the core component of the control valve, which generates displacement through the drive of the pneumatic actuator, changes the flow area of the control valve, and realizes the regulation of the fluid. The spool and seat are the key components of the control valve, which determine the sealing performance and flow capacity of the control valve.
2. Selection of pneumatic diaphragm control valve
In industrial control systems, choosing the right pneumatic diaphragm control valve is the key to ensuring the proper operation of the system. Choosing the right air-operated diaphragm control valve needs to consider the following aspects:
1. Fluid characteristics: It is necessary to consider the temperature, pressure, viscosity, corrosiveness, flammability and explosive characteristics of the fluid medium, as well as the flow rate and flow direction of the medium.
2. Control requirements: The requirements of the control accuracy, response speed, stability and reliability of the system need to be considered.
3. Valve specifications: It is necessary to select the appropriate specifications of valves, including nominal diameter, connection method, connection size, etc.
4. Actuator: It is necessary to consider the type of actuator, output torque, thrust, stroke and other parameters of the actuator, as well as the control mode and signal interface of the actuator.
5. Environmental factors: It is necessary to consider the influence of the valve installation environment, such as temperature, humidity, vibration, magnetic field and other factors.
According to the comprehensive consideration of the above factors, the selection of suitable pneumatic diaphragm control valve can ensure the normal operation of the system, improve the control accuracy and reliability, and prolong the service life of the valve.
3. Application of pneumatic diaphragm regulating valve
Pneumatic diaphragm control valves are widely used in various industrial fields, such as chemical, petroleum, pharmaceutical, food, environmental protection, etc. In the chemical production process, the pneumatic diaphragm control valve can be used to control the temperature, pressure and liquid level of various chemical reactors to ensure the stability and safety of the production process. In the petroleum industry, pneumatic diaphragm control valves can be used to control parameters such as production and pressure in oil wells to improve oil production efficiency. In the pharmaceutical industry, pneumatic diaphragm control valves can be used to control parameters such as temperature and flow of liquid chemicals to ensure the quality and safety of pharmaceutical products. In environmental protection engineering, pneumatic diaphragm control valve can be used to control the flow and liquid level and other parameters of sewage treatment to improve the effect of sewage treatment. In a word, as an important industrial process control instrument, the pneumatic diaphragm control valve has a wide range of application prospects in various fields.