Is it more difficult to open and close a valve when there is back pressure?
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When there is back pressure on a valve, that means there is pressure at one end while there is no pressure at the other end. Is it more difficult to open or close such a valve? Please explain this to me, thank you; I don’t quite understand the principle. Points for help!
There is pressure, so of course there is more resistance
There is high resistance under pressure, making it difficult to switch on/off
①When the roughness of the contact surface is the same, the magnitude of the sliding friction force f is proportional to the normal force: f=μN (where μ is the coefficient of kinetic friction). ② When the pressure acting on an object is the same, the rougher the contact surface, the greater the sliding friction force. ③ The magnitude of the sliding friction force is slightly less than the maximum static friction force fmax. In typical calculations, it can be assumed that the maximum static friction force is equal to the kinetic friction force. Note: Within a certain range, the sliding friction force is independent of the contact area ； Sliding friction is independent of the object’s speed of motion
It depends on the structure; valves with different structures are affected differently by back pressure, and some valves are not affected by it at all
It’s inevitable – when there is unilateral pressure, the valve also has to overcome that pressure, so it’s difficult to open and close it. The greater the pressure difference on both sides, the harder it is to move
The resistance and friction force increase. More difficult to turn on and off