The opening and closing of the control valve require such great force
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Just a humble question: many chemical processing units operate under high pressure—over 50 kg/cm². For instance, the reactor in one unit operates at over 80 kg/cm², and a control valve is needed to regulate it. Given that the pressure is over 80 kg/cm², where does the control valve get the necessary pressure from to open or close the pipeline under such conditions? The wind pressure of the wind pressure regulating valve is generally 5-6 kilograms. I’m not quite sure about this; those who know could please provide a detailed explanation? Thank you
A control valve uses an actuator to control the opening and closing of the valve. The actuator can be of electric, pneumatic, or hydraulic type; they are capable of providing sufficient force to overcome the pressure of the medium, thereby opening or closing the valve. Although the air pressure of the pressure regulating valve is only 5-6 kilograms, it acts directly on the driving components of the actuator; through mechanical amplification or the lever principle, a force sufficient to handle high pressures can be generated to operate the valve. .
Pneumatic control valve: For pneumatic control valves, the operating pressure usually comes from gas sources such as compressed air or nitrogen. Although the air pressure at the pressure regulating valve is generally only 5-6 kilograms (i.e., 0.5-0.6 MPa), the pneumatic actuator can amplify this pressure through mechanisms such as levers and gears, thereby generating sufficient force to move the valve core and open or close high-pressure pipelines. Hydraulic control valve: A hydraulic control valve uses liquids such as hydraulic oil as the operating medium, and also amplifies the operating force through a transmission mechanism. Electric control valve: An electric control valve uses an electric motor to drive the actuator, thereby moving the valve core directly or indirectly. The torque or thrust generated by the electric motor, after passing through an appropriate transmission mechanism, can produce sufficient force to operate the high-pressure control valve.
The operating pressure of the material is not proportional to the air supply pressure of the control valve. The same goes for manually operating valves
For very high pressure differences, there is another type of valve design known as a balance spool, which balances the pressures above and below the spool, thus not interfering with its operation