[Smackre]

I have a big oil tank. Its pumping oil to 7 machines. Starts out with a 2" pipe and goes smaller and smaller. Well it has tons of GPM and pressure. But I need a way to control it at each seperate machine. Right now when one shuts off the coolant pressure goes up in the other 6 and if only 3 are running the pressure is to much. I need to be able to control it.

Also we have a drain that all the machines run into that goes back to the oil tank. And we have a flush flow as you call it hook to it. Its a nother coolant line running into the drain to flush it out.

So what do you normally use for 3/4" copper lines that has oil in it to control the flow and pressure? I want it so when one machine turns off it dont effect the rest.

[Geof]

Instead of regulators at each machine what about a pressure relief valve on the main line. When only a few machines are operating the relief valves just dumps the excess flow back into the main tank.

If you do want regulators and it is water mixed coolant I suggest the regulators that are used for domestic water supply. These mey not be appropriate for straight oil because the diaphragm and seals may not handle oil; actually they may not handle coolant.

[Smackre]

Its not water mixed coolant. We have a pressure regulator on the main line but it not a relief valve. I think you need pressure regulators at each machine to make each have a consistant pressure.

[Smackre]

Can you point me at a pressure relief valve that would work goef? Something that would work with oil.

[Geof]

Can you point me at a pressure relief valve that would work goef? Something that would work with oil.

I would look at hydraulic equipment, but your volume may be a bit high and pressure a bit low.

Partly what I had in mind was making something that would give you good flow variation at an almost constant back pressure; I am guessing your pressure is fairly low?

I made one quite a while back and I will try and describe it without resorting to pictures:

It had a vertical tube 2" ID and about 12" high with a row of holes up the side.

The inlet was at the bottom of the tube and inside the tube was a solid piston, no O-rings or anything, that was a loose fit.

With no flow and no pressure this piston would sit at the bottom of the vertical tube but as soon as flow started the pressure would lift the piston and uncover one or two holes and the fluid would escape.

The whole system was mounted above the coolant tank so the fluid just drained straight back into the tank.

When no coolant nozzles were open the piston would uncover several holes so all the flow escaped back into the tank and as coolant nozzles were turned on it would drop covering some of the escape holes.

On top of the piston was a rod that I put weights on to regulate the pressure; I was working at a maximum of about 25psi which needed about 75lbs of weight holding the piston down.

Because the weight stayed the same no matter how high the piston lifted the pressure remained fairly constant no matter how many holes were exposed. This is different to a spring operated valve where the pressure has to increase to compress the spring and expose more escape holes.