How to determine the flow in cfm or gm in a flow control valve?

[acr2003]

Hello everybody,
I have a low flow control valve with the following characteristics:
Cv = 0.1
Range: 4-20
I am not a valve expert so I don't understand this terminology and I am trying to read the flow from this valve. I not even know what is the flow unit in this case (cubic feet/min, gallons/min...?).
Does someone could please explain me how I could:
1. Set the desired flow.
2. Read it (in a specific flow unit system).
3. How Cv and range are related to the real flow across the valve?
If you need some more informatio, please let me know.
Any help is very much appreciated.
Thanks a lot.
acr

 

[jdarco]

Cv is a value showing flow through a valve (typically gallons per minute in the USA)with a 1psi pressure drop through the valve. Not sure what "range" refers to but the 4-20 leads me to think is refers to 4-20mA, which would be the input signal to tell the control valve how much to open or close. Your best bet would be to talk to the valve manufacturer to get more flow information.

 

[acr2003]

Thanks jdarco.