Page 1 of 3 123 LastLast
Results 1 to 13 of 34
  1. #1
    Join Date
    Mar 2011
    Location
    Northeast Missouri
    Posts
    61

    txv brazing techniques

    Like many of you Im sure, I am always looking for new tips and techniques on how to do my job better. So I have a question for you all. In my opinion the number one enemy of a txv,(not including possible debris getting by a filter/drier) is my torch. I have always been curious why they make us braze a part in that is sensitive to heat and has short stubs to braze too. I prefer flare but as you know this is not always practical.

    So my question: How do you go about brazing in a txv and protecting it from damage?

    Myself I use a liberal amount of a thermal absorbing paste and wrap it with a wet rag.

  2. #2
    Join Date
    Oct 2001
    Posts
    6,966
    take it apart down to the raw body and torch away... power hat and all
    "when in doubt...jump it out" http://www.youtube.com/watch?v=U1qEZHhJubY

  3. #3
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,921

  4. #4
    Join Date
    Mar 2011
    Location
    Texas
    Posts
    27
    I also like to use heat paste and wet rag. I also like to flux the joint it seems to help the silfoss run a little faster, making for a quicker weld.

  5. #5
    Join Date
    Sep 2009
    Location
    S.C.
    Posts
    1,412
    TXV's? I use what Certified Hacks use... StayBrite 8.

    After killing 2 TXV's on a 15 Ton Trane, I won't use 15% on a TXV unless I can cut it out and braze the tubes to the TXV, then swage the tubes back together. I've also used 1" Rags and the Squirt on heat stuff.
    Yes, I know I Shouldn't But I Just Can't Help Myself...

  6. #6
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    19,501
    I pack it with a tub full of Hot Dam.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  7. #7
    Join Date
    Feb 2006
    Location
    USA
    Posts
    4,381
    Quote Originally Posted by jpsmith1cm View Post
    Tear your rag into strips about 1" wide.

    Wrap the body tightly with them.

    Braze fast.
    that's pretty much the best method ive found so far

  8. #8
    Join Date
    Jun 2006
    Posts
    203
    i wrap it wth a wet rag and i have a spray bottle with water handy to keep rag cool and wet.

  9. #9
    Join Date
    Sep 2009
    Location
    Stumptown,USA
    Posts
    1,253
    Safety silv 1200 is 56% silver and is liquidus at 1200 degrees. Your Harris 15% is liquidus at 1480 degrees. That is almost 300 degrees hotter. Stay brite 8 is liquidus at 535 degrees. When I was an RCA Factory Service technician, we could only use Easy Flo 45% it is liquidus at 1100 degrees. You have to use flux with the "high silver" products. The copper tubing does not get discolored or a lot of oxides at these temperatures. Check out the Cap'n Hook torch tips from Uniweld, Smith versa torch has one too. Or a twin tip torch works well with a little practice. I did a walk in freezer txv with that small twin tip from Smith and wet rags. It turned out fine. The guys at one company I used to work for liked the orange or blue coated brazing rod, both are "high silver" products.
    Challenge yourself, take the CM test --- Certificate Member since 2004 ---Join RSES ---the HVAC/R training authority ---www.rses.org

  10. #10
    Join Date
    Sep 2007
    Location
    State College, PA
    Posts
    1,167
    Just replace the "guts".

    Not much can go wrong with the valve body (no moving parts). Just replace the power head and internal parts. Throw new body away.

    This requires no heat or torch.

    Faster and safer.

    *Note: This may not always work but will on 98% of TXV replacements.
    Can someone please explain to me -
    Why is there never enough time to do it right the first time, but plenty of time to do it twice?


    Please view site rules: http://hvac-talk.com/vbb/showthread.php?t=1241

    Apply for Pro Membership: http://hvac-talk.com/vbb/showthread.php?t=116113

    Find your local HVAC-Talk Contractor: http://icemeister.net/aop_map.html

  11. #11
    Join Date
    Jun 2006
    Posts
    203
    can you use stay bright# 8 on a fitting that you just sweated off a part that previously had silphos or does it have to be completly clean?

  12. #12
    Join Date
    Apr 2005
    Location
    where the beer flows like wine
    Posts
    2,871
    I use JB's Cool Gel,spray it all over the txv, number 3 tip, 15% rod and braze away, United sell it, way better than the paste, wet rag or paper towel would do the trick too.
    Most of the TXV's I've replaced were made either by Danfoss or Alco and most failed cause the bulb charge leaked,I always replace them with Sporlan, have very good luck with that brand.

  13. #13
    Join Date
    Sep 2009
    Location
    S.C.
    Posts
    1,412
    Quote Originally Posted by frio View Post
    can you use stay bright# 8 on a fitting that you just sweated off a part that previously had silphos or does it have to be completly clean?


    John Markel is the SB8 expert but from my experience it needs to be Completely Clean.


    I also keep CoolGel on the truck but Gosh Dang it's expensive!
    Yes, I know I Shouldn't But I Just Can't Help Myself...

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event