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Thread: Rubber hoses and glycol

  1. #1
    Join Date
    Oct 2006
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    Rapperswil, Switzerland
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    Rubber hoses and glycol

    About 2 Months ago I switched from ice water to glycol in my chiller. I had a bad start to the day one morning recently when I discovered that a rubber cooling line feeding one of the tanks from the fixed lines had burst.
    I lost about 900 litres of coolant before the pump eventually blew a fuse.

    I replaced the hose and noticed that it was really cracked and pitted. Admittedly it wasn't the newest of hoses but I was surprised.
    The wife of a friend of mine who is head nurse in a surgical ward remarked that they only use silicon hose on all cooling mashines due to the aggresive action of glycol.
    Is this a well known problem?
    What kind of hoses are recommended - silicon rubber seem a little unpractical to me.

    Would be interested to hear what the experience is out there.

  2. #2
    Join Date
    Feb 2004
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    Yuba City, Ca
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    From past experience in the industrial world, silicone rubber was a massive improvement in glycol(ethylene) coolant piping. The down side was creep and cost

  3. #3
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    Feb 2003
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    Boise, ID
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    That sounds like a bummer. Besides the PVC mainline, we have some pex and some braided lines. While I've never had such a problem with either, I would recommend the pex. It's good stuff, and easy to put together. Good luck!

  4. #4
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    Oct 2002
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    Athens, NY
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    Keep in mind that in the brewing world most use propylene glycol, not ethylene glycol. I don't know if it makes a difference when it comes to how corrosive they are to rubber hose, but the guys from pro refrigeration are a ton of help on all glycol issues. They're the moderators for this forum area so I'm sure they'll post a response in the next couple of days.

    good luck!
    Hutch Kugeman
    Head Beer Guy
    Crossroads Brewing
    Athens, NY

  5. #5
    Join Date
    Mar 2003
    Location
    Baton Rouge, LA
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    617
    Copper piping is fine too, just and inhibitor to keep it from scavaging the metal.
    I just had to replace my beer line chiller glycol due to a black mold growth. Pro- Any suggestions on additives to stop this from happining again?
    Operations Director, Tin Roof BC
    ted@tinroofbeer.com
    "Your results may vary"

  6. #6
    Join Date
    Jul 2005
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    Auburn, WA / Winston Salem, NC
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    233

    glycol hoses and PVC Piping

    Hoses are extremely common in wineries, as they are disconnecting and moving tanks often. At the request of several of these customers we began offering the hoses, and quick connect shut off fittings.

    Admittedly we simply matched the parameters of a hose product that was successfully "field proven" by several wineries, and worked with a hose specialist for this recommendation. It is a nitrile rubber inner surface. I will definitely forward to the manufacturer the questions from this thread.

    Follow the hyperlink for a specification sheet of the hose product that we offer:

    http://www.unisource-mfg.com/product...0&categoryid=7

    I am sure that any local hose supplier can match the specs. Unisource, out of Portland OR is a good source for information. http://www.unisource-mfg.com

    Not to change the subject, but I was planning to try and get a thread started on PVC and glycol loops. Just recently there has been a lot of debate about PVC, of any grade, being suitable for glycol piping loops. I know that over half of the chiller systems we have manufactured are installed with PVC piping, and many/most I suspect have served well for these customers. I have talked recently with a PVC manufacturer, the glycol manufacturer, and a contractor fighting one of these issues. I havenít been able to get to the bottom of exactly what is causing the isolated cases of PVC piping system failures, and will be working to learn more about this.

    I will suggest to anyone considering PVC as a piping material to take a serious look at copper or possibly ABS Piping- the manufacturers of both of these products will go on record approving these for glycol systems. I will post more as information becomes available. If anyone has any comments, concerns, observations, etc- please forward to me or post them here.

    Thanks,

    Jim
    Pro Refrigeration Inc.

  7. #7
    Join Date
    Jan 2007
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    Bonaire, Netherlands Antilles
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    pipe wrapping a good idea with copper

    Remember that copper is an excellent conductor of heat, exactly what you don't want in any exposed piping run. If it runs for more than a few meters, wrap it in insulation to prevent unnecessary heat transfer and unwelcome condensation.

  8. #8
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    Oct 2006
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    Rapperswil, Switzerland
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    propylene or ethylene glycol

    Quote Originally Posted by kugeman
    Keep in mind that in the brewing world most use propylene glycol, not ethylene glycol. I don't know if it makes a difference when it comes to how corrosive they are to rubber hose
    good luck!

    Good point kugeman!

    Now that I will have to re-glycol my chiller I would like to take it into consideration.

    Any advice here Jim? Is ethylene glycol less/more agressive than propylene glycol?

    By the way , I checked out the specifications of the recommended hose and although I can't be certain I think my hoses are (old) nitrile inner liners.
    I had to make a quick replacement and did so with metal sheathed "rubber" available from plumbing shops. I coudn't find any silicon hose on short notice that held up to any pressure.

    Steve

  9. #9
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    Jul 2005
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    Auburn, WA / Winston Salem, NC
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    no ethylene

    Ethylene glycol is not "foodgrade" and shouldn't be used, propylene glycol is "food grade". The antifreeze in your car is an ethylene based glycol.

    Check out the article posted on the Refrigeration Section of Probrewer. There are also several grades of glycol, we specify USP grade propylene glycol to be used in all of our systems.

    Hope this helps.

    Jim
    Pro Refrigeration Inc.

  10. #10
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    Feb 2004
    Location
    Yuba City, Ca
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    I didn't want to infer that Ethylene glycol can be used! Its use should be strictly limited to non-food industrial use. It is regarded as a hazmat item. In the realm of piping and hose hose material, there are so many factors you have to consider. We are are in the process of plumbing in with Industrial ABS (not DWV). Temp range, shrinkage and capatibilty are factors.

  11. #11
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    Jul 2005
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    Auburn, WA / Winston Salem, NC
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    Quote Originally Posted by msmartin
    I didn't want to infer that Ethylene glycol can be used! Its use should be strictly limited to non-food industrial use. It is regarded as a hazmat item.
    I am surprised how often this questions does come up, especially from contractors familiar with servicing industrial/AC chiller systems that utilize ethylene glycol. I just wanted to make sure everyone knows that ethylene glycol shouldn't be considered.

    Quote Originally Posted by msmartin
    In the realm of piping and hose hose material, there are so many factors you have to consider. We are are in the process of plumbing in with Industrial ABS (not DWV). Temp range, shrinkage and capatibilty are factors.
    Industrial ABS is a great choice and would be my recommendation!

    Good Luck,

    Jim

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