Can the wind pressure control valve be closed?
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In chemical production, pressure control valves are widely used. The supply air pressure for these valves is between 0.6 and 0.8 MPa. Here’s a question: if the pressure of the medium flowing through a control valve is around ten kilograms per square centimeter, and it is necessary to close the valve in order to cut off the flow of this medium, how can the valve be closed using purified air as the driving force? Purified air has only a pressure of a few kilograms per square centimeter – how can it then drive the actuator to close a valve whose medium has a higher pressure? I don’t understand. In other words, the pressure of the cleaning air is low; this causes the actuator of the control valve to move. Does the actuator also generate a pressure of a few kilograms?
The closing function of the wind pressure control valve primarily depends on its design and the type of actuator used. In the situation you mentioned, the actuator of the control valve needs to use purified air at a lower pressure to close the medium flow path, even though the pressure of the medium is much higher than that of the purified air. Typically, the actuator of a control valve (such as a pneumatic actuator) is designed to be able to amplify the input pressure through a cylinder or similar mechanism, even when the supply pressure of the purge air is low. This is achieved through mechanical leverage, pressure difference action, or specially designed cylinders. This design enables a lower input pressure to generate sufficient force to close the valve, thereby blocking a medium with a pressure much higher than that of the input pressure. If you are concerned that the existing control valve cannot effectively shut off high-pressure media, it may be necessary to check whether the valve’s specifications meet the application requirements, or to consider using a valve type better suited for high pressure differences, such as a pneumatic actuator with a pressure-boosting mechanism. In some high-demand application scenarios, specialized security assessments and system design adjustments may also be required. .
It is recommended to consult the manual for pneumatic valves; it contains diagrams that make the working principle clear at a glance. The principle is related to the force-bearing area of the valve cylinder; for reference only. “Should a “wind pressure control valve” be called a “pneumatic control valve”? “Should “air supply pressure” and “purified air” be referred to as “instrument air pressure”? ““A few kilograms of pressure”? It is best to standardize the vocabulary to facilitate information retrieval and discussion, for reference.
Agree with what was said above; even if the original poster isn’t from an instrumentation field, this description is far too casual. In simple terms, it’s a matter of pressure and stress.