Page 1 of 2 12 LastLast
Results 1 to 13 of 24
  1. #1
    Join Date
    Jul 2008
    Location
    Las Vegas
    Posts
    3
    Post Likes

    Cleaning TXV screen without losing charge.

    I need some expert advice. I am currently working on a new casino refr system. It is a parallel system with many master and slave systems on one main line. We are having an issue with dirty TXVs. Some of the slave coils have no valves and the system is too large to pump down into the reciever. Our freezer system has 600 pounds of 404a. Does anyone know how to clean the TXV screen without losing any refrigerant? Any assistance would be great, the boss isnt in til late tomorrow and I would like to have all TXVs cleaned by the time he gets in. There is roughly 25 of them, thanx.

  2. #2
    Join Date
    Jul 2008
    Location
    Denver, CO
    Posts
    4,294
    Post Likes
    Quote Originally Posted by jerseyjon729 View Post
    I need some expert advice. I am currently working on a new casino refr system. It is a parallel system with many master and slave systems on one main line. We are having an issue with dirty TXVs. Some of the slave coils have no valves and the system is too large to pump down into the reciever. Our freezer system has 600 pounds of 404a. Does anyone know how to clean the TXV screen without losing any refrigerant? Any assistance would be great, the boss isnt in til late tomorrow and I would like to have all TXVs cleaned by the time he gets in. There is roughly 25 of them, thanx.
    What makes you think you have dirty TXV's? What are the symptoms?. You are stuck recovering the refrigerant down to a point to where you can hold the rest in the condenser and reveiver. Then your raceing the clock to get them all done before your product gets spoiled. I would consider calling a contractor that can diagnose the problem first and if he deems TXV replacement necissary then he has this kind of equipent and man power to get the job done.
    Last edited by Tiger93rsl; 07-22-2008 at 09:22 PM.

  3. #3
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Post Likes
    Quote Originally Posted by jerseyjon729 View Post
    Does anyone know how to clean the TXV screen without losing any refrigerant?
    Yup - either pump the circuit/sytem down or recover the refrigerant.

  4. #4
    Join Date
    Jun 2005
    Location
    Las Vegas NV
    Posts
    1,215
    Post Likes
    jersey,

    As Tiger and MT stated, you'll have to pump them down or recover. Does this system have any isolation valves? Sounds like you might have an Omni-Temp system.

    Call me at JS Vegas if you need anything.

    powell

  5. #5
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    6,067
    Post Likes
    sounds like a good place for this tool.

    http://www.hvacr-tools.com/mm5/merch...=PINCHOFFTOOLS

    pinch off the lines on both sides of the valve
    clean screen or replace valve
    re-round lines

    of course this will only work if the lines are small enough

  6. #6
    Join Date
    Jun 2003
    Location
    Chicago, IL
    Posts
    6,067
    Post Likes
    deleted
    Last edited by craig1; 07-22-2008 at 09:50 PM. Reason: quoted my own post when i meant to edit it

  7. #7
    Join Date
    Mar 2008
    Location
    arkansas
    Posts
    78
    Post Likes
    if you do all that work would it be worth the time and materials to put in iso valves on each txv so if the problem exists again you just shut down system and loose verry little 404? and inspect and clean, sounds like a contaminated system

  8. #8
    Join Date
    Nov 2003
    Posts
    1,867
    Post Likes
    Quote Originally Posted by jerseyjon729 View Post
    I need some expert advice. I am currently working on a new casino refr system. It is a parallel system with many master and slave systems on one main line. We are having an issue with dirty TXVs. Some of the slave coils have no valves and the system is too large to pump down into the reciever. Our freezer system has 600 pounds of 404a. Does anyone know how to clean the TXV screen without losing any refrigerant?
    How many shutoff valves are there? If you have a suction shutoff valve at the rack for one system, you can pump some refrigerant out to the fixtures.


    Quote Originally Posted by jerseyjon729 View Post
    Any assistance would be great, the boss isnt in til late tomorrow and I would like to have all TXVs cleaned by the time he gets in. There is roughly 25 of them, thanx.
    Usually trying to impress the boss with very little knowledge never works the way we dream of in our head.

  9. #9
    Join Date
    Jan 2007
    Location
    Kansas the real Oz
    Posts
    17
    Post Likes

    Dirty screens

    New system you say, Sounds like the system was brazed up without using nitrogen, if that is the case it may continue to plug screens for awhile. I'm following up a contractor now who did this. I have refused to sign off on final payment until all filter dryers are changed. even this won't solve all the problems. This is a 110,000 sq foot grocery store. one trick I have used where receivers are too small, is to use a recovery tank as an additional receiver by hooking it to the liq. line ahead of the shut off valve. There is generally a gauge port at the shut off valve on the receiver, hook it there, use a scale so as not to overfill the recovery tank or tanks. Close off the liq line valve and allow the system to fill the recovery tanks. This is much faster than using a recovery machine. Pump out as much as required until the receiver will hold the remainder. If you are pumping down with a large compressor, you may need to throttle the shut off valve open and close so you don't shut down on high head pr. There are never enough ball valves on a system until they begin leaking, then there are too many. Be careful watch your high side gauge
    Mike

  10. #10
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Post Likes
    Quote Originally Posted by smilies View Post

    Usually trying to impress the boss with very little knowledge never works the way we dream of in our head.
    Ain't THAT the truth!

  11. #11
    Join Date
    Jul 2008
    Location
    Las Vegas
    Posts
    3
    Post Likes
    Thread Starter

    solution

    luckily we had ball valves on most of the individual coils. On some we didnt, the contractor did not put them in. Also the contractor piped a few thousand feet of lines without nitrogen........no comment. On the coils without shutoff valves we closed the solenoids and manually closed the TXVs, therefore isolating the portion of liquid line between the solenoid and txv(about 5 inches) we could then clean our screens and insert back into the system with minimal loss and purged our line to minimize contamination. It may not e the best way, but it was the only way to do it given the circumstances. At the end we opened our txvs to their correct adjustment and our freezers are working great. We will be doing it again tomorow to ensure that we have clean screens. I just love cleaning up other peoples messes, but thats the trade we choose.

  12. #12
    Join Date
    Sep 2005
    Location
    florida
    Posts
    5,530
    Post Likes
    Quote Originally Posted by markettech View Post
    Yup - either pump the circuit/sytem down or recover the refrigerant.
    How ya do that?you mean it cant be done on the fly.
    I love the smell of phosgene first thing in the morning:

    To apply for professional membership click here


    Educational forums are open.

    If you would like to submit a link or an article or other related info to the EF. click here

  13. #13
    Join Date
    Jun 2001
    Location
    Michigan
    Posts
    12,077
    Post Likes
    Beat the livin $hit out of it with the biggest hammer you can find, until it starts working. That's what I do. Works. Try it. If it don't call Markettech. He is awesome with technical support on these things. I have his number if you need it.

Page 1 of 2 12 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
  •