Ethylene Glycol

[Iceman717]

I have a screw compressor that uses an ethylene glycol/water mixture to cool the oil via a shell & tube heat exchanger. It is then pumped to a closed-circuit cooler on the roof and back. It also supplies underfloor heat for one of the spiral freezers.

The system level is low and what I need to know is will any old EG work or do I need something special? I know I need something with a rust inhibitor because of all of the black pipe in the system but I've heard that certain cheaper grades of glycol won't hold up to being constantly recirculated. Anyone know?

[MikeHolm]

FWIK, the base glycol will be the same and the difference is in the inhibitors. My own preference would be to clean it out and switch to propylene glycol which is not toxic but you have slightly different pumping and heat transfer characteristics. It is often less reactive with some plastic piping types.

[Iceman717]

FWIK, the base glycol will be the same and the difference is in the inhibitors. My own preference would be to clean it out and switch to propylene glycol which is not toxic but you have slightly different pumping and heat transfer characteristics. It is often less reactive with some plastic piping types.

That would be my preference as well but the powers that be won't go for that. I doubt if there is even any inhibitor in the system now.

[MikeHolm]

Tell them their insurance rates for spills will go down big time, haha