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View Full Version : Need Glycol Leak Sealant That's Food Grade



HOBWI
12-02-2011, 08:15 AM
I have some small leaks at a few threaded connections in my glycol system. I have recommendations for non-food grade type sealants, but can't use them as I make cold liquor via a heat exchanger which poses the risk of cross contamination.

Any recommendations for a good FOOD GRADE sealant?

Currently, I've just taken the fittings apart and wrapped more teflon tape, but it doesn't always work. The paste has been terrible; it seems to promote leaks.

Thanks,

Page

jimvgjr
12-02-2011, 09:55 PM
Sometimes a combination of Teflon tape (applied first) and a Teflon based paste is the solution. I know the Teflon paste is approved for potable plumbing systems and should be fine for this application. I'm not aware of a food grade thread sealant tape but will inquire to some of our suppliers and report back.

If these are plastic threaded fittings into metal fittings, you may also look at replacing with flanged connections.

Good luck,

Jim
Pro Refrigeration Inc

sbradt
12-03-2011, 06:35 AM
If you check McMaster-Carr they have some really heavy mil-spec thread tape that is really good stuff, especially on sharp stainless threads. That might help.

If, as Jim suggested, you have plastic threaded to metal, I have found that it is almost impossible to make a reliable connection if the plastic is the female side of the connection. It appears that the metal contracts more than the plastic does when it gets cold and opens up the joint. If you can use a metal fitting to convert it to female metal x male pipe, the opposite is true and it may actually tighten the joint as it gets colder.

I've had so many bad experiences with pipe dope sealants that I've given up on them for anything but gas lines, which they have some advantages on.