need to throttle water quickly and automated

[bob1111]

We have an application where we will need to throttle water flow very quickly and precisely. Specs are 40-60psi, 30-40gpm, and full open to full closed in .1sec or less with ability to precisely tune in partial openings.

We need a rather economical solution here. We have considered a poppet style like a turbo wastegate or a butterfly valve. Either of these controlled with an air cylinder and pwm an air solenoid to vary the pressure to the valve or find a type of servo control for this to be all electric.

Could anyone off any opinions on our ideas and maybe other ideas or hard parts to test our theories? We are thinking air might be the easiest but may fight flutter or inconsistent valve control. Not sure.

 

[JLSeagull]

Look for the Fisher Control Valve Handbook. Consider a globe style control valve.

http://www.documentation.emersonprocess.com/groups/public/documents/book/cvh99.pdf

 

[Zapster]

full open to full closed in .1 sec or less with ability to precisely tune in partial openings

Are you sure you need 100-0% throttling in 0.1 second? Define "rather economical." I think your response time of 0.1 second will destroy the concept of economical.

 

[bob1111]

We know the air cylinder can open and close the valve in this short of time but regulating partial open and varying the position might present a challenge with air.

Economical - we priced simple electric valves at over 800 dollars that that is way to costly. We can buy a simple butterfly for 80 bucks and provide our own automation that should prove faster and more accurate.

 

[Artisi]

Seems you have already answered your own question.

Have you considered likely impact from waterhammer on such an instantaneous flow interuption?

 

[bob1111]

Yes and the hammer effect should not cause a problem if we go this route. We had also considered modulating the solenoid of a direct acting valve but concerned that the pulsing we will get for water flow may cause a problem in fluctuating performance.

 

[MechEng2005]

Could two separate valves be used? One quick-response shut-off valve and one that would have a variable opening? This might be easier to obtain than looking for both features in a single valve.

For the record though, I don't have experinence with these types of applications. My experience in piping is somewhat limited.

-- MechEng2005