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  1. #1

    Hmm changing out a 7.5 ton TXV

    Well it was the first time changing out a soldered TXV on Carrier unit and I had some kind of issues with unsweating the old one. Using a Turbo Torch #32 head I thought big enough) couldn't get the old TXV out. Finally with 2d tip smaller was able to unsolder...In putting the new one (Dan Foss Brass Body) soldering it I had put the Nu-Calgon Thermopaste to protect the valve(on the valve body) as well as wrap a wet rag around the valve body. Well I had a terrible time soldering in the new valve(nitrogen flowing). I never used the thermo-paste before and I'm looking for input in techniques used in soldering in a 7 1/2 ton expansion brass body valve. What a time in getting enough heat to solder the 1 1/8 manifold to outlet of valve...Ideas????

  2. #2
    Join Date
    Apr 2012
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    Lots of soaking wet rags. Tie them down with a wire tie and a spray bottle of water to resoak the rags.

    I put in a 20 ton that was installed with 45%.

    Had to get the copper cherry for the new stuff to stick. I dont us that paste stuff.

    Sometimes the old school way is the best.

    They make a rod thats orange colored. That stuff is great for joints that have alot of mixed mateeial on them.

    You still have to get the copper cherry hot before it will stick.

  3. #3
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    Also you should invest in a rosebud tip.

    Make your life a lot easier but be careful with it.

    That 20 to was 1 5/8 and was no problem.

    Rags have to be WET not wetted and wrung out.

  4. #4
    Join Date
    Jun 2012
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    I have run into this problem several times. I started cutting the old one out installing a new piece of pipe. I don't try and braze or solder back onto the same piece of liquid line or destributor anymore. No matter how clean you think you got it.

    I use the same rag and spray bottle technique ass Six mentioned. Minus the zip ties which I will now use.

  5. #5
    Join Date
    Jun 2012
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    Northeast
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    Also do you use a flow regulator for your nitrogen. You cant get the nitrogen flow down low enough with the standard regulator. At least I never could. I set it up to barely be flowing through. I lick my finger and hold it over the pipe. If it gets cold it is good for me.

  6. #6
    Join Date
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    68,104
    Paste flux and 45% silver works well. Along with cool gel. Also, put the bulb in a cup of ice water.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  7. #7
    Join Date
    Jun 2012
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    Quote Originally Posted by beenthere View Post
    Paste flux and 45% silver works well. Along with cool gel. Also, put the bulb in a cup of ice water.
    Great point about the bulb. I will be using this also for now on.

  8. #8
    Join Date
    Jun 2006
    Location
    New Jersey
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    4,337
    Any TXV or distributor is a cake walk now. Keep a tube of them for that special occasion. Low temp and flows like butter.

    http://www.harrisproductsgroup.com/e...Silv-56FC.aspx

  9. #9
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    Quote Originally Posted by beenthere View Post
    Paste flux and 45% silver works well. Along with cool gel. Also, put the bulb in a cup of ice water.
    Aww man why didn't I think of that ?

    Good tip.

  10. #10
    Join Date
    Sep 2007
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    NH
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    1,151
    I rip rags up about 1" or 2" wide. Get em wet but not so wet it's drippin all over your valve and rap them tight. Use 56% or 45% and white paste flux or the orange rod for brass bodys. If your real worried about over heating it, take the power head right off.... O ya it's a danfoss I forgot you might not be able to.

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