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  1. #1
    Join Date
    Dec 2002
    Location
    in a house, Appomattox, Va.
    Posts
    3,442

    oh no,pvc in geo system, leaking

    I've had a geo system been to several times. Heard at geo training class don't use pvc threaded into metal, or will loosen up over time.

    This system has a unit in attic of two storey building, pumps are in basement, has buffer tank by pumps. the 1st unit on manifold off tank keeps loosing pumps, and the fittings keep leaking.

    I believe the issue is the pvc to metal threaded connections at pump and in attic. Any one know good way to fix this type joint dependably.

    I've checked w/ rep on flanged connection, but he says may still be problematic. Boss is going to try using the 10' hose kit for pump to unit connection to make the transition- pvc, brass barb fittings off each connection to the hoses.

    what think you?
    Col 3:23


    questions asked, answers received, ignorance abated

  2. #2
    Join Date
    Jul 2011
    Location
    East coast USA
    Posts
    1,002
    I have used flanged. worked fine. I had many leaks but this was on a closed loop heat pump system. sometimes the water would get to warm and expand then contract. and the leaks always came from the threaded parts. Just don't tighten to much on the pvc. But pvc is bad very bad

  3. #3
    Join Date
    Jan 2007
    Location
    Stongsville Oh
    Posts
    948
    Have you ever heard of wicking fittings? I had a German brand chiller that would constantly leak during install and test. The fittings were supplied by the manufacturer. Brass male adapters but had no taper like our fittings. After many phone calls I was instructed to wick the fittings. I talked to an old plumber that showed me how and it worked. Can't say that I ever needed to do that again and I don't know that wicking a plastic fitting is right but I would check into it.
    ckartson
    I didn't write the book I just read it!

  4. #4
    Join Date
    Sep 2002
    Posts
    13,551
    What is fitting wicking? How do you do it?

    PHM
    ------




    Quote Originally Posted by ckartson View Post
    Have you ever heard of wicking fittings? I had a German brand chiller that would constantly leak during install and test. The fittings were supplied by the manufacturer. Brass male adapters but had no taper like our fittings. After many phone calls I was instructed to wick the fittings. I talked to an old plumber that showed me how and it worked. Can't say that I ever needed to do that again and I don't know that wicking a plastic fitting is right but I would check into it.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  5. #5
    Join Date
    Jan 2007
    Location
    Stongsville Oh
    Posts
    948
    Candle wicking wound onto the threads a certain way then pipe dope over that. The wicking has five or six strand but they are unraveled to a single strand. The plumber that showed me this was quite old but very happy to teach me something that hasn't been in use for quite a few years. It did work where no amount of Teflon tape would. The chiller is German made and is used with seimens MRI machines but I can't remember the name. I will try to find more on this on line because it would be very hard to explain the process, kind of like explaining how to tie a shoelace. I brought a nipple and candle wicking that I bought at the supply house where I got some incredible looks until someone said,"Yeh we got that, haven't sold any in years".
    ckartson
    I didn't write the book I just read it!

  6. #6
    Join Date
    Jan 2007
    Location
    Stongsville Oh
    Posts
    948
    http://www.heatinghelp.com/forum-thr...ealing-Threads

    I found someone describing the same issue I had and used the wicking.
    ckartson
    I didn't write the book I just read it!

  7. #7
    Join Date
    Sep 2002
    Posts
    13,551
    Oh: thread in the threads?

    Hell; I thought I invented that. <g>

    I used to use it on high pressure hydraulic piping and on refrigerant threads - like relief valves and access valves. I would dope the male threads, wind a piece of heavy cotton thread into the root, and then screw the fitting together.

    PHM
    ------




    Quote Originally Posted by ckartson View Post
    http://www.heatinghelp.com/forum-thr...ealing-Threads

    I found someone describing the same issue I had and used the wicking.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  8. #8
    Join Date
    Feb 2011
    Location
    Peoria, IL
    Posts
    2,243
    I only use metal mip, or fip adaptors, so the male or female, is metal, and the other socket side is pvc. (what size are the lines?) except on a condensate line that is.

  9. #9
    Join Date
    Dec 2002
    Location
    in a house, Appomattox, Va.
    Posts
    3,442
    I had a job where I wanted pipe thread. boss showed up w/ another brand of pipe dope "they said would work just as well. ended up having someone come out to weld up the pipe after the fact- wasn't going to dismantle all that 3 and 4" pipe.
    Col 3:23


    questions asked, answers received, ignorance abated

  10. #10
    Join Date
    Dec 2002
    Location
    in a house, Appomattox, Va.
    Posts
    3,442
    The hose showed up at shop today. not sure I would trust it on negative pressure not to collapse over time. I think I'd rather try the flanges, instead. Thank you. I put two posts because the return key is not working in the reply box for some reason.
    Col 3:23


    questions asked, answers received, ignorance abated

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