Hi, this is little housekeeper, control in the automatic control of modern factory, the regulator plays a very important role, the production of the factory depends on the flow of the medium right assignment and control, the control of both the exchange of energy, low pressure or is a simple container loading, will need some final control element to complete, function variable resistance of the regulating valve in the pipeline,
Body type 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, such as spherical,
In specific choices, 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) wear resistance when fluid medium is suspending liquid containing high concentrations of wear particles, the interior of the valve material is hard,
(3) corrosion resistance due to the corrosive medium, 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, when the temperature, 250 degrees Celsius or higher should add the radiator,
(5) prevent flash flash and cavitation 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,
Regulating valve actuators in order to make the regulator to work properly, with the implementation of the mechanism need to be able to produce enough output power to ensure that highly seal and valve opening,
For double-acting pneumatic, hydraulic, electric actuators, are generally not reset spring, the size of the force has nothing to do with its direction, therefore, the selection of the actuator is the key to find out the biggest output force and rotational torque of the motor, for single acting pneumatic actuators, the output power is associated with the opening of the valve, regulating valve on the emergence of the force will also affect the movement characteristics, therefore needs to be established throughout the regulator of the opening range force balance,
On the actuator output force is determined, according to the process using the environment requirements, choose the corresponding actuator, for the scene have explosion-proof requirements, should choose pneumatic actuators, considering from the aspects of energy saving, should choose electric actuators, as far as possible if the adjustment of high precision, hydraulic actuator options are available, such as power plants transparent machine speed regulation, the refinery catalytic unit reactor temperature adjusting control,
The role of regulating valve way only when choosing pneumatic actuators, the role of way through positive and negative effect and positive effect of the valve actuator combination form, there are four kinds of combinations are (gas close type), positive and negative (gas) type (gas) type anyway, narrow (gas close type), through the four combinations have spirit way on and off the function of regulating valve two kinds,
For the choice of the ways of regulating valve function, mainly from three aspects:
A) process safety; B) the characteristics of medium; C) to ensure product quality, the economic loss minimum,

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