Changing glycol

[BigWilley]

How often should I change out the glycol in the system?

[jimvgjr]

Good Question.

I spoke with Steve Pescatore of the Houghton Chemical Company and asked him this question. Houghton manufacturers Safe T Therm Propylene Glycol Based Fluid.

He commented that on an open, non pressurized, system you're looking at a 2-3 year life cycle on the Glycol Solution. This is with solutions that are USP Grade based. Lesser grades of Glycol will break down sooner. He also commented that in some industries, such as dairy, they require it be changed automatically every 3 years due to the risk of bacteria.

Most glycol manufacturers will provide free testing of your solution, and will provide recommended additives or inhibitors. Houghton, for example, will test one sample per year for free of their product- and will test other manufacturer's products for a fee of $150.00. I believe Dow has a similar offer.

Good Luck,

Jim

[BigWilley]

I should have also added, does glycol degenerate in storage if not in use. We have a big drum of it that is more than 3 years old but unused.

[jimvgjr]

You might want to have it tested, but if it has been stored in a sealed container, you should be good.

Steve, Houghton Chemical, mentioned that in closed, pressurized, systems the glycol can last as long as 10-15 years.

Jim