I have a closed system that got water in it. The oil foamed up (would this prevent the pressure relief from operating correctly??)I wish to remove it. I drained the resevoir. Some suggestions were to use fuel line antifreeze then drain it. I was thinking of using clean fluid and turning the pump slowly to purge the system but I would like your opinions. THANKS

More system info: Small scale. Resevoir is only about 2 gallons

With the informatio given:

If it was my system I would drain all the oil that would come out easily, refill and run the circuit for 30 minutes while cycling the actuators. Then, do the same scenario several more times until the drained oil clears up.

I have done as above on large circuits and disconnectrd the return lines to tank and piped them into a container. This keeps the contaminated oil in the circuit from getting back to tank.

One such system was a coil processing line that was 300' long and had 256 actuators. The oil finally cleared up after dumping and refilling with 2,700 gallons of oil. Fortuanately this company reprocessed their oil by filtering it and using centrifuges to remove water so the flushed oil was not wasted.

The other option is to drain all possible oil, remove all Lines and actuators, drain and clean them by at least flushing them with new oil, reassemble, fill and start anew.

Water alone should not have any effect on the Relief Valve operaion. The mixture sometimes gets into a Cottage Cheese type mixture and can plug orifices or restrict part movement in the Relief Valve that are necessary for correct operation.

THanks Bud.
I'll flush the system several times with clean oil.
The system is belt driven by a gas motor,does it matter whether I start the motor (high speed), or just use the starter to turn it over? for purging.

If I heat the contaminated oil up, can I boil out the water and reuse it?

again thanks for your expertise

I would start and run the circuit at some elevated speed and cycle the actutors at least several minutes to try and mix the oil in the Dead End circuits as much as possible after each oil dump and refill.

Heating is one way I have seen it done. Keep the heat below 150 Deg.F. so you don't deteriorate the oil by excess heat. That will require more time but won't hurt the oil.

Also leaving it set in a container for a couple of months usually allows for separation since water has a higher Specific gravity than oil.

I once bought a Ford tractor that had been setting for two years.I checked the oil by pulling the stick and it looked as clean as if someone had just changed it it was so clear. However, I got it started and drove it about 2 miles to my home and found the oil on the stick was now a Yellow/White mixture that did'nt even look like Engine oil. It seems all the water had separated over the time the tractor set, and if I had drained and refilled the oil before I started the engine I would have seen water at first and then oil drain out.