Cv vs Position in a Gate Valve
Cv vs Position in a Gate Valve
(OP)
thread408-211223: Cv vs Position in a Gate Valve
Can anybody help me on how to estimate Cv vs %open in a gate valve?
The mate of the closed thread has done that, and I´d like to know how...
Can anybody help me on how to estimate Cv vs %open in a gate valve?
The mate of the closed thread has done that, and I´d like to know how...
RE: Cv vs Position in a Gate Valve
The responses in your linked thread were pretty clear to me. There is no single empirical formula to do this as it is situational. The documents most conductive to you learning about calculating Cv and flow in general are Crane TP410 and the Fisher Control valve handbook. Those two books will explain more than any individual in this forum can. That being said here are my suggestions on how to go about this. The Cv will be roughly proportional to the cross sectional area exposed to flow. If half of the circular area is exposed the Cv would be roughly equivalent to 50% of the full open Cv. You won't get a ton of position/Cv accuracy, but it should give you a rough estimate of how it is changing. Another method if you have a characteristic curve for a similar valve is to scale it to the full Cv of your specific vale. The most accurate way as previously mentioned is to test your valve.
RE: Cv vs Position in a Gate Valve
Handbook of Hydraulic resistance by Idelchik
Best regards, Morten
--- Best regards, Morten Andersen
RE: Cv vs Position in a Gate Valve
But, IMO, it won't be able to apply it for the real flow pattern on the gate valve similar to that of the globe valve.
RE: Cv vs Position in a Gate Valve
Just need to be a bit smart about how you calculate the Cv from the crane equations…
As previously mentioned in the thread this should only be for information not as a means of using a gate valv to control the fluid.
RE: Cv vs Position in a Gate Valve
Luke | Valve Hax | https://valvehax.com/
RE: Cv vs Position in a Gate Valve
(www.spitfireresearch.com)
RE: Cv vs Position in a Gate Valve
1. You should under all circumstances select a regulating valve for regulating.
2. You might use a gate valve to regulate a flow, but always under very limited conditions regarding flow speed and pressure differences.
3. You might try to calculate a result, but have to check the result 'in the field'.
4. The valve will be damaged (most likely by cavitation) if calculated or operated outside possible limits.
RE: Cv vs Position in a Gate Valve
it is really difficult to do.... it better installed a control valve to do the job.
horacio
https://www.linkedin.com/company/lagotuy/
RE: Cv vs Position in a Gate Valve
https://www.industrialcontrolsonline.com/training/...
Gate valves are fairly linear.