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Thread: RTAA EXV

  1. #1
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    RTAA EXV

    Here's the hail Mary:

    This weekend I'll be replacing an EXV on an '07 RTAA110. Trane left precious little copper between the 1-5/8" flare and the valve, so it looks like it needs to be sweated out and back in.

    Anyone have any pearls of wisdom or general advice on how to wrangle this beast out and back in?

    TIA

  2. #2
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    This is a fairly simple job. Is this your first time doing it?

  3. #3
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    Thread Starter
    Quote Originally Posted by manny2326 View Post
    This is a fairly simple job. Is this your first time doing it?
    Yes, first time changing an EXV w/copper this large. Been in the industry 10 years and never burned up a valve, but this one gets my blood pressure up.

  4. #4
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    I just did an EXV on a CGAM today. Little smaller, 7/8"X1 1/8". I left it fully assembled. Purged with nitro the whole time, even after it was apart.
    I did something different this time. I wrapped a shop towel (disposable wipe all) around it, used zip ties to position a garden hose and slowly trickled cold water over it while I was brazing.
    I had no discoloration at all and was able to touch the valve with my bare hand 30 seconds after.
    I have not started it yet (evacuating) but I'm 100% sure there is no damage.
    -----Stop, step back, relax and have another go at it.-----

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  6. #5
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    if you're intimidated with this i think you shouldn't do it. its a relatively small valve there is no reason to be intimidated you have to do the same thing you do when you install a txv on a 2 ton unit. keep the heat away from it and wrap it with a wet rag.

  7. #6
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    Not a big deal, like manny said, wrap it with a wet towel and keep the heat away. Is this valve an exact replacement? The reason I ask is if you have the old style valve, they're no longer available and you have to upgrade to the new style valve which means you have to replace both valves and the 1U3 module that drives the valves.

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  9. #7
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    Thread Starter
    The IOM states the valve change occurred in 2003, so my unit made the cut. The valves are physically identical, and all diagrams in the IOM match my new valve.

    Like I said, I've swapped more than a couple valves and I just wasn't sure if any special technique applied.

    It's been so hot down here, I'm surprised I can't just wiggle it loose.

  10. #8
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    I'll just throw out there what I tell the younger "greener" guys.

    Just because it's an EXV or a TXV, don't be afraid of the heat.

    Pick a tip one size larger than you would think. Get a good hot noisy flame with a sharp bright pencil tip. Get it hot, flow the fos and get out. I've seen more damage by taking too long with too small of a tip.

    I'm not saying anything against you. Just something I try to pass along. You may already know this. Personally, I'd run at least a #3 tip, maybe a #4. Keep it wrapped, keep it wet and you'll be fine!
    -----Stop, step back, relax and have another go at it.-----

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  12. #9
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    If you are really worried about it, get some of the heat blocking putty and then wrap with rags.

    X2 on the bigger tip. Keeps the heat localized.

    Sent from my SM-N910W8 using Tapatalk
    Last edited by BALloyd; 07-20-2017 at 11:57 PM.

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  14. #10
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    Thread Starter
    Thanks to BALloyd, BennyD, and R123 (Apologies, but I don't know how to link to your user names).

    I already picked up some of the new "Wetrag" putty stuff, and some ThermoTrap, and some rags, etc. The parts house guys were raving about Wetrag...I'll know more Saturday night. From what I've gathered, standard practices shall prevail: nitro purge and flo while brazing, and keep heat off the valve, etc.

    And I never let intimidation stop me...if I did, I'd still be swapping 1-pole contactors in back yards. Read, ask, and beg when necessary.

  15. #11
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    Two weeks ago finished up the upgrade on RTAA170, don't worry about pipe size the exvs aren't too bad getting out. The one I just did was remote evap so much more room and ease to work


    Sent from my iPhone using Tapatalk

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  17. #12
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    Apr 2013
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    Take it apart don't ding the knife edge seals and nail it with a rosebud it's easy.

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