Low volume flow control

[rmayer]

Hello,

We have a process involving several streams feeding in at slightly different pressures. We were using Plastomatic flow control valves in different sizes for each stream to achieve the right proportion. These work as a variable orifice reacting to pressure to always permit only the specified gpm to pass. The problem with using them is that they all need to be changed out to accomplish an update on proportion and there isn't a convenient method for fault detection other than on the net measurement of output which can only suggest that one of them is clogged or malfunctioning.

I was thinking of trying a PWM controlled solenoid in conjunction with a flowmeter on each circuit. While this would obviously be a more costly way to go, it would give the chemists the ability to change proportion with a mere software upgrade via PLC reflash. Does anyone here have any recommendations for flowmeters on the order of 1gpm that would function as low as 15psi? Do you think it will be posslible to find solenoids that will stand up to say 100Hz cycling?

On the other hand, if anyone has experience with some type of small stepper controlled variable orifice flow control, that was going to be my backup.

 

[moltenmetal]

Have a look at Hass Manufacturing (

http://www.hassmfg.com)

. He has some nice stepper-controlled needle valves he calls the "Intellifaucet". Nothing too high tech, and reasonably priced.

 

[unclesyd]

We have used the Reasearch Control Valve products in all our bench and pilot plant units for many years.

http://www.badgermeter.com/Industrial/Valve-Products/Research-Control-Valve.aspx

 

[dogtop]

Second unclesyd's suggestion. Great valves for pilot plants.