Variable Position Ball Valves?

[TriangleIL]

Would like input from those who have used variable position (floating?) ball valves in their builds. What valves would you recommend? Where have you found the valves? Were they difficult to calibrate?

I would like to be able to control the flow for various valves in my build via electrical signal (either touch screen interface, potentiometer switch, other?). Any input would be greatly appreciated.

 

[kladue]

I am using Belimo proportional ball valves that take a 1-10VDC signal for position. Control of the Belimo proportional valves can be by potentiometer or analog output from an interface module. There are some folks using low cost dc powered ball valves, they can be used for what is known as floating control but the control method is based on timed pulses in open or closed direction.

 

[TriangleIL]

Thanks for the reply! Would something like this work? What does the Cv value mean on these valves? I.e. whats the difference between the first link and this one?

It looks like Cv is the flow coefficient? Any idea what Cv I would need? As far as I can tell, I'm looking at a Cv of approximately 3-6? I am currently estimating 10gpm with a pressure drop of 5psi (though I have no idea here)

 

[kladue]

Here is a link to the proportional valve http://www.energyequipment.com/p-10235-belimo-b207btr24-sr-us.aspx. "CV" is a measure of flow that creates 2 PSI pressure drop through device. The Belimo valves have plastic restrictor disks that give the various CV factors for same valve body, a pair of snap ring pliers will pop the retaining ring and plastic disk out for wide open valve flow.

 

[TriangleIL]

Kladue,

Thanks for the valve advice. I purchased one to play with initially and get the hang of things. I'm also looking at the following valves to control on/off where I do not care about flow rate. I believe others are using the same valves... just looking for a confirmatoin from a few people before I take the plunge. These are rated to 115psi, I assume thats fine for the LG pumps?