Hello,
Get in touch with Tom Wanke at the Fluid Power Institute in the Milwaukee School of Engineering Applied Technology Dept.(It's in Milwaukee Wisconsin). He is well able to talk you through this, or at least point you to information that will be of use. Non-profit, so no sales pitch, just...
Hello Alex,
Have you thought of a vortex type valve. They are simple to fabricate. You push in the air/fluid mix tangentially at one end of a cylinder, allow it to rotate downwards towards an exit stream 180 degrees from the inlet. You then have a bleed hole at the top center of the...