Could you please tell me about the pressure reducing valve?
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When the purchased pressure reducing valve is used on the pipeline, it can reduce the pressure normally when the pipeline is clear, but when the outlet is closed, the pressure gauge on the outlet pipeline will slowly increase the pressure until it is the same as the pressure in front of the valve. I think this phenomenon is abnormal, but the manufacturer said this is normal, and the boss also said this is normal. I can't understand it! Pressure reducing valves are used on oil lines and steam. Is there any standard for pressure reducing valves? Thank you all! This post was last edited by firep on 2007-12-23 12:46 ]
The pressure reducing valve relies on the balance of the force of the spring and the force of the fluid on the valve disc to achieve the purpose of reducing pressure. This is illustrated by the above example.: When the pipeline is unobstructed, the pressure downstream of the pressure reducing valve is the pressure after pressure reduction P1. Since the outlet valve is open, the back pressure is constant, so P1 is also constant, and the outlet can depressurize normally. When the outlet is closed, P1 first decreases. At this time, the feedback of P1 causes the spring to move in the direction of increasing pressure. When the valve is opened, the outlet pressure rises until it reaches equilibrium. Since the valve on the outlet pipeline is closed, the increased pressure will be maintained. It is normal for the pressure reducing valve to be in a new equilibrium state under this condition.
But if that is the case, doesn’t the pressure of the pipeline in the rear section of the pressure reducing valve also need to be tested according to the pressure level in the front section? Moreover, the inlet pressure reducing valve of many automatic control valves can only ensure the stability of the rear section pressure, and will not rise due to the closure of the rear section valve! The pressure reducing valve relies on the spring on the outlet side to balance the outlet pressure. If the outlet pressure is too high, it should drive the inlet throttling device to open and reduce. If it is too high, the inlet throttling device should be closed? I hope you can explain what kind of pressure reducing valve can stabilize the pressure in the rear section, and what kind of pressure reducing valve cannot stabilize the pressure for a long time when the rear section valve is closed. Thank you. * * Got it! :handshake