Call Us
+86-0519-85503155
EN
ja 
ko 
fr 
de 
es 
ru 
pt 
ar 
vi 
tr 
th 
EN
ja 
ko 
fr 
de 
es 
ru 
pt 
ar 
vi 
tr 
th 
Oct 07 2023
Read More
The control valve is the actuator in the automatic control system, and its application quality is directly reflected in the adjustment quality of the system. As a terminal element in process control, people have a newer understanding of its importance than in the past. The quality of the control valve application, in addition to the quality of the product itself, whether the user is correctly installed, used, and maintained, it is very important to calculate and select correctly. Due to the error of calculation and selection, the system starts and stops, and some even cannot be used. Therefore, users and system designers should recognize the importance of valves on site, and must pay enough attention to the selection of control valves.
The control valve has the characteristics of simple structure and reliable action, but because it is in direct contact with the process medium, its performance directly affects the quality of the system and environmental pollution, so the control valve must be regularly maintained and repaired, especially for harsh and important operating conditions. On occasion, more attention should be paid to maintenance work of inspection sites.
For control valves used in high pressure difference and corrosive media, the valve body wall and the diaphragm of the diaphragm valve are often impacted and corroded by the medium, and the pressure and corrosion resistance must be checked.
When the control valve is working, due to the infiltration of the medium, the inner surface of the thread used for fixing the valve seat is easily corroded and the valve seat is loosened, so attention should be paid during inspection. For valves that work under high pressure difference, it is also necessary to check whether the sealing surface of the valve seat is damaged.
The valve core is a movable part during adjustment work, and it is most seriously eroded and corroded by the medium. During maintenance, it is necessary to 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), attention should be paid. When the valve core is seriously damaged, it should be replaced. In addition, attention should be paid to whether the valve stem also has a similar phenomenon, or the connection with the valve core is loose.
"O" rings and other gaskets. Check whether the diaphragm and "O"-shaped gasket in the control valve are aging and cracked.
Pay attention to whether the PTFE packing and sealing grease are aging, and whether the mating surface is damaged, and should be replaced when necessary.
The control valve is the main type of actuator, which changes the fluid flow by power operation by receiving the control signal output by the regulating control unit. Control valves generally consist of actuators and valves. According to the power used by its equipped actuator, the control valve can be divided into three types: pneumatic, electric and hydraulic, namely the pneumatic control valve using compressed air as the power source, the electric control valve using electricity as the power source, and the liquid medium (such as oil) pressure-driven hydraulic control valve, in addition, according to its function and characteristics, there are solenoid valve, electronic, intelligent, fieldbus control valve and so on.
