regulating compressed air line pressures

[john18436572]

At work we have plant supplied compressed air lines. We have a few large pressure regulators, that feed smaller lines that go to individual equipment and air nozzles for blowing stuff off. Each piece of equipment and air nozzle has it"s own smaller regulator. They want me to label all the regs with what pressure they should be set at. The smaller regs at the ends of the runs need to be set at anywhere from 30psi to 80psi. As a general rule, what should the main regulators that are upstream be set at? I assume that if they are too low there will be pressure losses at the end use regs if they are all being used at the same time?

 

[Uncle Ernie]

If the regulators are sized correctly the pressure settings should have no effect on the volume of air they pass no matter what the pressure setting.
I am not sure why you have several stages of regulation in your plant. What is the main line pressure coming from your compressors? The only reason I can think of that you would have upstream regulation would be to limit the pressure on the downstream regulators to below the maximum they can tolerate. That is what I would expect the upstream regulators to be set for.

 

[PaulW_NJ]

Based upon your description, sounds like you"ve got multiple take-off points. In my barn the compressor sits downstairs, where it"s take off is regulated at 100-110 psi for running impact guns, etc. Then the air is piped upstairs to my woodshop, where it"s takeoff is 40-60 psi for nail and staple guns. You could just run compressor outlet to each site and regulate down all the way at each, but doing it in stages works best if the highest takeoff is closest to the compressor. The size of the regulator controls the flow you can get at a certain pressure.

 

[james rumph]

I used to install automation tooling in the auto plants tell they closed everthing down up here.

To answer your question , is the plant on a loop system ? Meaning does the air supply in circle the entire plant, it leaves the air compressor and goes all the way around and returns to the air compressor.

Most big plants do this so theres never a low presure area due to useage.

"Anyway" if you follow the letter of the law "OSHA" the plants should be running at 80 psi.
Well every plant i have been in we have turned them up or the plant has to run around 90 to 110 psi.

Grant you in these cases the supply lines are like 1" and they go down from there.

I hooked up a sand blasting cabnet in the shop and read the instruction "imagine that" and they said the for top performance that it required no less then a 1/2 in line up 20' from the source. They went on to say that anything further required a 3/4" hose and operating presure was only 60 psi.

We have found that in plants that don't have loop systems that presure is very important due the fact that someone up stream might be drawing alot of air by witch it effects everything down stream.

To get around these problems we will install expansion tanks in equipment. It is really a secondary air tank that holds a reserve of air to help with presure problems. 20 -40 lbs tanks.

I have seen plants use old air compressor tanks "big" in problem areas of the plants to combat presure problems.


I wish i could give you the answer you need but there is so many factors in your question that only you know.