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.