Selection of the vent valve diameter
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This post was last edited by zhaohh3211 on 2012-4-10 13:57 to stabilize the pressure of the valve equipment. When the pressure exceeds a certain level, the valve opens to release pressure. But the problem is that the process pipe diameter is 100. The CV value calculated based on the conditions specified in the process indicates that a valve with a size of 25 will be sufficient. But I don’t dare to make a choice – if I pick a too small size, I’m worried it won’t be able to handle the pressure in case of an accident; if I pick a too large size, I’m concerned about frequent switching and an unstable system pressure: lol How should I determine this?
1. Inform the process team of the calculation results, so that they can confirm the parameters again. II. Why it doesn’t seem like a form of regulation; would using a on/off valve work? III. Reducing the diameter to 25 is definitely not feasible; at least 50 is required, with 65 also being an option to consider. My humble opinion!
The last edit to this post was made by zhaohh3211 on 2012-4-11 at 11:28. The problem often lies in whether the conditions specified in the process match those under fault conditions; only by establishing accurate basic conditions can the right instruments be selected. There are regulating type and shut-off type relief valves; please check what the process requires. For some relief valves, the system stops operating after they discharge, so the requirements in such cases are less stringent, making it easier to make a choice. If driving continues after the pressure is released, it is necessary to maintain stable pressure levels; higher standards are required, and it seems that the owner’s requirements for the process involve such standards. Wait until all the conditions have been specified before choosing the instrument.
It is normal for the calculated CV value of the relief valve to be low due to the relatively large differential pressure; under such conditions, it is difficult to obtain particularly accurate values through process analysis. Generally, blowdown valves generate quite a lot of noise. You can reduce this noise by adding noise-damping panels to increase the pressure behind the valve, thereby reducing the pressure difference acting on the valve core; in this case, it might be advisable to use a valve with a diameter of DN50 or larger. Choosing 25 is definitely not appropriate
Thank you, everyone. I know 25 definitely won’t work; I just want to hear everyone’s opinions