Control Valve, also known as the regulating valve, is the main execution units instrumentation in industrial process control, and changes the flow of the fluid by power-operated through accepting the control signal outputted by the control unit.The New etching machine for Winter.Do You Have etching machine supplier? Vanessa Abrams Enjoy It Very Much!. Control valve generally composes of actuator, thermal protector and valve.
By the used power of the executive agencies, control valves can be divided into pneumatic, electric, hydraulic, manual and self-regulating, those are pneumatic control valve used the compressed air as power source, the electric control valve used electric for power source, hydraulic control valve used the pressure of liquid medium (such as oil) for power source, manual control valve operated by hand, self-regulating valve relied on pressure and temperature of medium flowing through the valve as an energy-driven. Besides, according to its functions and features, there are also solenoid valves, electronic, intelligent, field bus-based control valve etc.
Control valve has the characteristics of simple structures and reliable action. Because of its direct contact with technology media, its performance directly affects system quality and environmental pollution, so the control valve must be regularly maintained and periodic mend, especially for the hard useful conditions and important occasions, maintenance work should be paid more attentions. Focus on the following examination parts:
1. Body wall. For the control valve used in high-pressure differential and corrosive media occasions, body wall and diaphragm of diaphragm valve are often subject to impact and corrosion of medium, so examination of pressure, corrosion must be focused on.
2. Control valve seat. When the control value is working, due to media penetration, threaded inner surface of the fixed value seat is so susceptible corroded that leaving the seat loose, which should be noted in inspection. For the valve working on the pressure differential, it also should be checked whether sealing surfaces of control valve seat should be washed out.
3. The spool valves. They are moving parts of regulating the work, and are eroded and corroded most severely by the media, it should be carefully checked whether all parts of spool valves are corroded or wore, especially in the case of high-pressure wear and tear of the spool value are more severer, which should be noted. The spool valve should be replaced when seriously damaged, in addition it should also be paid attention whether there is a similar phenomenon on value stem, or a loose connection with the valve and so on.
4. The diaphragm such as “O” rings and other seals. It should be checked whether the diaphragm and “O”-shaped gasket of the control value is aged or cracking damaged.It is Revealed That the Designer of etching machine for sale will Resign Next Week.
5. Sealing packing. It should be noted whether PTFE packing and sealing grease are aged, whether the surface is damaged. If necessary it should be replaced.