Maintenance of monoblock control valves

Monoblock control valves have the characteristics of simple structure and reliable operation, but because they are in direct contact with process media, their performance directly affects system quality and environmental pollution, so control valves must be regularly maintained and regularly inspected, especially for harsh and important occasions.
1. Inner wall of valve body
For control valves used in high pressure difference and corrosive media, the inner wall of the valve body and the diaphragm of the diaphragm valve are often impacted and corroded by the media, and the pressure resistance and corrosion resistance must be checked.
2. Valve seat
When the monoblock control valve is working, the inner surface of the thread used to fix the valve seat is easily corroded due to the infiltration of the medium, which makes the valve seat loose. Attention should be paid during inspection. For valves working under high pressure difference, the valve seat sealing surface should also be checked for damage.
3. Valve core
The valve core is a movable part during adjustment work, which is most seriously eroded and corroded by the medium. During maintenance, carefully check whether the various parts of the valve core are corroded and worn, especially in the case of high pressure difference, the wear of the valve core is more serious (due to cavitation), which should be paid attention to. If the valve core is seriously damaged, it should be replaced. In addition, attention should be paid to whether the valve stem has similar phenomena or the connection with the valve core is loose.
4. Diaphragm
"O" ring and other gaskets. The diaphragm and "O" gasket in the single-block control valve should be checked for aging and cracking.
5. Sealing packing
Pay attention to whether the polytetrafluoroethylene packing and sealing lubricating grease are aging, and whether the mating surface is damaged. Replace it when necessary.
The regulating valve, also known as the control valve, is the main type of actuator. It changes the fluid flow rate by receiving the control signal output by the regulating control unit and using power operation. The regulating valve is generally composed of an actuator and a valve. According to the power used by the actuator, the regulating valve can be divided into three types: pneumatic, electric, and hydraulic, that is, pneumatic regulating valves with compressed air as the power source, electric regulating valves with electricity as the power source, and electro-hydraulic regulating valves with liquid medium (such as oil) pressure as the power source. In addition, according to their functions and characteristics, there are solenoid valves, electronic, intelligent, fieldbus type regulating valves, etc.