Pneumatic single-seat control valves: principle, application and maintenance.
I. Introduction. In industrial automation control systems, pneumatic single-seat control valves play an important role. It is a device that uses a pneumatic actuator to drive the valve to open and close, so as to realize the automatic adjustment of the parameters such as the flow, pressure, and temperature of the pipeline medium. It has the advantages of simple structure, reliable action, stable performance and high adjustment accuracy, and is widely used in the automatic control system of petroleum, chemical industry, metallurgy, electric power, light industry and other departments.
Second, the working principle of pneumatic single-seat control valve.
The pneumatic single-seat control valve is mainly composed of two parts: pneumatic actuator and single-seat valve body. According to the size of the control signal, the pneumatic actuator generates the corresponding thrust or pulling force to drive the valve core in the single-seat valve body to move up and down, thereby changing the flow area between the valve core and the valve seat, so as to achieve the purpose of adjusting the flow, pressure or temperature of the pipeline medium.
3. Application field of pneumatic single-seat control valve.
Petroleum and chemical industry: used to control the flow, pressure and temperature of various corrosive media, high temperature and high pressure steam pipelines.
Power industry: used for boiler feedwater, steam turbine bypass control and other systems to achieve automatic adjustment.
Metallurgical industry: used in blast furnace gas**, hot blast furnace combustion control and other systems to improve energy efficiency.
Light industry: used in the food, beverage, pharmaceutical and other industries of automated production lines to ensure product quality and production safety.
Fourth, the maintenance and maintenance of pneumatic single-seat control valve.
Regularly check whether the air source pressure of the pneumatic actuator is normal to ensure the normal operation of the actuator.
Clean the inside of the valve body regularly to prevent impurities in the medium from blocking the gap between the valve core and the valve seat and affecting the adjustment performance.
Regularly calibrate the pneumatic single-seat control valve to ensure that its adjustment accuracy meets the process requirements.
For pneumatic single-seat control valves that are not used for a long time, they should be opened and closed regularly to prevent the valve from jamming or the actuator from malfunctioning.
V. Conclusions. As an important automatic control device, the pneumatic single-seat control valve plays an irreplaceable role in various fields. Understanding its working principle and application field, and mastering the correct maintenance and maintenance methods are of great significance to ensure the normal operation of the pneumatic single-seat control valve and prolong its service life.