Regulating valve and control valve, by accepting conditioning control unit of the output control signal, from engine operation to change fluid flow regulating valve and valve general, the executing agency, if by their ticket enforcement agencies use the power, the valve can be divided into pneumatic control valve, electric valve, hydraulic control valve of three, namely to compressed air to power sources pneumatic - valve, with electricity as the power sources of electric regulator, as a liquid medium (such as oil) pressure as the power of electric hydraulic control valve, in addition, according to its function and feature points, and the hydraulic control valves, solenoid valves, electronic, intelligent type, site general linear regulator, regulator valve type selection of regulating valve body is a lot of more phyletic, the commonly used types of the body is through single-seat, pass-through two-seater, angular, diaphragm, small flow rate, tee, eccentric rotating, butterfly, sleeve, spherical, etc., in the concrete when the choice, to do the following consideration:
1, the shape of the valve core structure
Mainly based on the selected flow characteristic and unbalanced force factors, such as
2, resistance to wear and tear "
When fluid medium is suspending liquid containing high concentrations of wear particles, the interior of the valve material is hard,
3, the corrosion resistance
Because of the corrosive medium, try to choose structure simple valves.
4, medium temperature, pressure,
When the medium temperature, high pressure and the change is big, should choose the valve core and valve seat materials by temperature, pressure changes small valves,
5, prevent flash and cavitation
Flash and cavitation in liquid medium, only in the process of practical production, flash and cavitation will form the vibration and noise, shorten the service life of the valve, therefore when selecting valves should prevent the valve from flash and cavitation, the choice of control valve actuators in order to make the regulator to work properly, with the implementation of the mechanism to produce enough output power to ensure highly seal and valve opening,