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  1. #14
    Join Date
    Feb 2008
    Location
    Lucas, TX
    Posts
    107
    > Then it means that in 16 years he never read the installation instructions...

    So true...

    I guess the HVAC companies don't practice continuing education. This is the next thing to ask for when getting quotes for new systems...

    Adam

  2. #15
    Join Date
    Jun 2008
    Location
    LONDON
    Posts
    57

    nitrogen

    Quote Originally Posted by mikelcs View Post
    Lack of proper knowlege does not make you a fool. Not learning from, or listening to an educated, experienced tech or tech support, will certianly make you a fool. Nitrogen purge while brazing is proper operating procedure.

    Very good advise.That is why the install of VRV/VRF system is expensive
    and a bit slow process.

  3. #16
    Join Date
    Aug 2006
    Posts
    6

    Here's a picture with and without nitrogen purging

    ...I wouldn't mind doing a little bench test. Brazing a line and the charging a some with nitrogen and do the brazing. Cut the (2) lines right down the middle long ways and compare the interior...
    Attached Images Attached Images

  4. #17
    Join Date
    Dec 2007
    Location
    Soudern Kaliphonistan
    Posts
    283
    I do use nitro when brazing, cause "its the right thing to do", for all the reasons listed.

    Has me wondering, we use Argon for TIG welding, would nitro work? It serves the same function.......???

  5. #18
    Join Date
    Dec 2007
    Location
    Ohio
    Posts
    2,876
    Quote Originally Posted by shortly View Post
    ...I wouldn't mind doing a little bench test. Brazing a line and the charging a some with nitrogen and do the brazing. Cut the (2) lines right down the middle long ways and compare the interior...
    Nice pics! The proof is in the pudding!!
    I need a new signature.....

  6. #19
    Join Date
    Mar 2003
    Posts
    1,234
    As part of my training we use a bender, swage, flare tool etc. and then fit pieces of copper together. First we braze without nitro purging then the next one with nitro purge and most guys are amazed at the difference. I've been nitro purging for 35 years now. Fortunetly I was taught by an excellent tech. that always insisted on "reading and following the instructions".

  7. #20
    Join Date
    Feb 2006
    Location
    Tn.
    Posts
    1,344



  8. #21
    Join Date
    Apr 2008
    Posts
    36
    Yes, it's the proper way to do it. However, the vast majority of the time you're not going to have problems if you don't do, so most techs don't. Sad, sure... but true.

  9. #22
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,915
    Quote Originally Posted by Chozn1 View Post
    Yes, it's the proper way to do it. However, the vast majority of the time you're not going to have problems if you don't do, so most techs don't. Sad, sure... but true.
    If by "problems" you mean killing the system outright in a short period of time, then sure, the vast majority of the time it won't.

    Usually it just makes the system less efficient due to partially clogged metering device inlet screens and filter driers causing some extra pressure drop, or plating of sealing surfaces and the valves in the compressor, or shortens the life of the compressor due to extra wear caused by an abrasive compound mixing with the oil.
    If more government is the answer, then it's a really stupid question.

  10. #23
    Join Date
    May 2008
    Location
    North Texas
    Posts
    105
    Usually it just makes the system less efficient due to partially clogged metering device inlet screens and filter driers causing some extra pressure drop, or plating of sealing surfaces and the valves in the compressor, or shortens the life of the compressor due to extra wear caused by an abrasive compound mixing with the oil.
    But other than that, Mrs. Lincoln, how did you enjoy the play?

  11. #24
    Join Date
    Sep 2008
    Location
    Mesquite Tx.
    Posts
    375
    It is basic refrigeration practice to purge with nitrogen when brazing. As the picture in the earlier post shows, you will be amazed how clean and shiny the copper is. Are the schools not teaching this? Judging by the responses here, I get the impression they don't. Every book on procedures I have read states this, as well as install instructions. Since you should have the nitrogen on hand to leak check, it is easy to use it to purge. Not getting on anyones case here, if you haven't been taught, you won't know it.

  12. #25
    Join Date
    Aug 2008
    Location
    Burlington , Mass
    Posts
    470
    I have built or remodeled many supermarket refrigeration rooms with new equipment, lines , walkins, cases etc. We started running nitro through the lines back in 1980. I'll say we did have no problems with flaking/scale plugging the txv's, and saw no sign of any foreign mat'l in the suction filters. It is a very good practice to get into, but the extra time it takes should be considered as far as labor, and cost of tank refills.

    I believe the manufacturers, Hill, Tyler, etc, highly recommended this procedure, as well as the engineers. It was outlined in the contracts.


    Its standard procedure today. Even for a residential split AC. It takes less time to connect the nitro gauge hose than it would to troubleshoot a plugged distributor or TXV.
    I'll be there when I get there and not a minute later

  13. #26
    Join Date
    Jul 2008
    Posts
    7
    Quote Originally Posted by double bogey View Post
    It is basic refrigeration practice to purge with nitrogen when brazing. As the picture in the earlier post shows, you will be amazed how clean and shiny the copper is. Are the schools not teaching this? Judging by the responses here, I get the impression they don't. Every book on procedures I have read states this, as well as install instructions. Since you should have the nitrogen on hand to leak check, it is easy to use it to purge. Not getting on anyones case here, if you haven't been taught, you won't know it.
    I wasn't told anything about that in school, but hey, as someone pointed out earlier, the proof is in the pudding, and there can be no doubt in my mind after seeing those pics

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