electrically controlled(Remote) Proportional control valve requirement

Do you really want to DESIGN a proportional valve or have I misunderstood you text?

If you intend to do the design, I would suggest to buy one since you may not be aware but such a design is not at all a children' game and please believe me I did it already years ago.

If you mean that you want to select the best valve for your system then the data you communicate are totally insufficient for it.

A valve is selected according to the flow and pressure drop you can use depending on the cylinder load and speed you want to obtain and the dynamics imposed by the control loop in order to reach the accuracy level required by the final goal be it a speed, acceleration, position or force target.

If you need more informations you should first give more about your need.

I am designing fluid mixing circuits with a 200 to 300 gph gear pump and a recirculation loop with 2 inputs (Vacuum side) and one output (pressure side) of much lower flow. Input (A) is 5% to 20% of the total outflow of 30 to 100 gph. Input (A) might be 80 psi or as low as 5 psi as reduced through a prv. Input (B) is usually 2 to 10 psi.

Is there a simple proportioning device that does not cost an arm and a leg?

OR Is ther a simple way to set the proportions using an orifice or valves?

Just hoping,

Charlie Tuna

It is possible to design a special proprtionning device based only on hydraulics but of course the dispersion can be higher than with an electrically driven valve. So that you could give a tolerance value to the 2 values you indicate.

I designed such a device many years ago for a 2 components system using as above only hydraulics. It worked without problems but the ratio was not extremelly precise due to temperature influences on oil behaviour.

Depending on the tolerances I can tell you which way to go. Any way the more precise the more expensive will be the control.

Thanks.

I would like to know the flow within plus or minus 3 to 5 percent.

Charlie Tuna

I shall have to make some estimations you get an answer in a couple of days.

I may misunderstand your specific needs but I was thinking color valves might be appropriate .These simple in line devises would allow you to adjust the flows to whatever flows you need and are around $50 .If your not familiar with these see Parker hydraulics I hope this gives you an inexpensive adjustable solution that it appears your looking for if not it's worth a shot to try to help.

I do use a color coded needle valve on the water line only. It works well to adjust the flow. I also have a rotometer on each line. Here is my question. Can I take the flow readings from the rotometer on each line (before the pump) and claim, without successful contradiction, that I can accurately compute the percent water in the resulting mixture?

Charlie Tuna

wouldn't it be a simple matter to measure the output of the separate ingredients as they exit your setup, in beakers, and calculate the ratio .

Yeah, I probably have to continue building these machines then measure the ratio after the fact for each fuel type, each neeedle valve setting for each demand flow. Sort of reverse engineering vice formulaic predictions.

My machine needs to be adjustable so the customer can have us either 'dial-in' a water ratio that either minimized fuel usage or minimizes NOx emssions. That plus every engine type and boiler type behaves differently.

Exactly why get into formulas when actual flows will be field proven .The beauty of the collar valves is they give a fairly reliable metering that can be reproduced by returning to a setting .All the calculations in the world will not produce exact results so I like the simplicity .

I'm sure some people would spend hours and dollars to predict results that would never pan out in the field.