Factors to be considered in the purchase of regulating valve

Factors to be considered in the purchase of regulating valve

The regulating valve, also known as the control valve, is the final control element in the field of industrial automation process control, which changes the process parameters such as medium flow, pressure, temperature and liquid level by receiving the control signal output by the regulating control unit and with the help of power operation. It is generally composed of actuator and valve.

There are many types of valve bodies for regulating valves. The commonly used types of valve bodies include straight through single seat, straight through double seat, angle, diaphragm, small flow, tee, eccentric rotation, butterfly, sleeve, spherical, etc.

According to the power used by the actuator, the regulating valve can be divided into pneumatic regulating valve, electric regulating valve and hydraulic regulating valve, that is, the pneumatic regulating valve with compressed air as the power source, the electric regulating valve with electricity as the power source and the electro-hydraulic regulating valve with liquid medium (such as oil) pressure as the power. In addition, according to its functions and characteristics, there are hydraulic control valves, solenoid valves, electronic, intelligent, on-site general line regulating valves, etc.

It is suggested that when selecting the regulating valve, the following considerations can be taken into account:

1. Temperature and pressure of medium

When the temperature and pressure of the medium are high and change greatly, the valve whose material of valve core and valve seat is less affected by the change of temperature and pressure shall be selected.

2. Valve core shape structure

It is mainly considered according to the selected flow characteristics, unbalanced force and other factors.

3. Corrosion resistance

The structure of the valve shall be simple and corrosive.

4. Prevent flash and cavitation

Flash and cavitation occur only in liquid media. In the actual production process, flashing and cavitation will form vibration and noise and shorten the service life of the valve. Therefore, when selecting the valve, the valve shall be prevented from flashing and cavitation.

5. Wear resistance

When the fluid medium is a suspension containing high concentration of abrasive particles, the internal material of the valve should be hard.