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Thread: Installing TXV

  1. #1
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    Jul 2001
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    I installed a txv valve in an air-handler and i did not remove the fixed metering device since i did not see how the distributor would evenly distribute the gas to 6 different tubes with-out the oraface installed. I know in the supermarket systems the txv needs a nozel before the distrubutor. I had 8 degrees superheat and 20 degrees sub-cooling with it still in place, do you think i will have any trouble?
    Aire Serv of SW Connecticut- Gas heat, dual fuel and central a/c systems installed and serviced

  2. #2
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    You need to remove the piston unlees it is .100 or bigger. The MD will give too much of a restriction. Rheem is the only unit I know of that gives a big piston to replace original one.
    Karst means cave. So, I search for caves.

  3. #3
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    I still do not believe if i removed the piston i would have even flow to all distributor tubes

    Maybe i will get a few 100 pistons for this purpose.
    Aire Serv of SW Connecticut- Gas heat, dual fuel and central a/c systems installed and serviced

  4. #4
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    What did the instructions with the TXV say. I've never seen
    a retro-fit TXV kit for air-conditioning coils that didn't
    require removal of the orifice. What brand airhandler do you
    have there?
    Whoa Maynard - that's not how it works.

  5. #5
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    Jan 2005
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    48
    Just my two cents...but why meter a metering device? A proper working TXV will run 10-15 s/h, you just added basically a restriction condensing more liquid into the coil and back at your compressor...so future problems. Charge TXV's by s/c but get rid of the orifice first.

  6. #6
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    Go to the rheemote site and look up the size piston that is needed for the tonnage. It is not .100 I just threw a number out there.


    Search in pro section for a password I posted for Rheemote.
    Karst means cave. So, I search for caves.

  7. #7
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    I looked it up for you.

    Ton Piston

    1.5 .099
    2 .120
    2.5 .140
    3 .157
    3.5 .157
    5 .172

    This is for Rheem, other manuf. may difer.
    Karst means cave. So, I search for caves.

  8. #8
    Join Date
    Jan 2005
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    Im a Rheem dealer and just did a a/h same situation, they dont sell a 12 seer a/h only 10...need to add/braze in a TXV kit that came with a (think 89 orfice) thought it was odd and called my rep....no answers so chucked the orifice, thing dialed in perfectly s/c 10 s/h 12. Never with any other brand have i had to use a orifice with a TXV.

  9. #9
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    Jun 2001
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    This idea may be up for discussion. I would think that since the low pressure side of the coil (circuits) would be an equal pressure drop compared to the high side, that there would be an equal 'pulling' effect of the refrigerant into all of the feeders.

    The only exception I can see is if you have a blocked feeder, one having a longer circuit than another, or a distributer header that is causing more to flow in one than the other due to the placement of the feeders in it.

  10. #10
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    If you left a metering orfice in, your defeating most of the ability of the txv.

    Rheem uses a blancing orfice with a txv, not a regulating orfice.

    Did you check the amp draw.

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  11. #11
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    The manufacturer did not rate the coil for a TXV. The valve did work and the main reason i installed a valve was to prevent flooding (zoning), which it will do fine, thanks men! I installed a non-oem sporlan!
    Aire Serv of SW Connecticut- Gas heat, dual fuel and central a/c systems installed and serviced

  12. #12
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    Apr 2004
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    Originally posted by jaxman
    Im a Rheem dealer and just did a a/h same situation, they dont sell a 12 seer a/h only 10...need to add/braze in a TXV kit that came with a (think 89 orfice) thought it was odd and called my rep....no answers so chucked the orifice, thing dialed in perfectly s/c 10 s/h 12. Never with any other brand have i had to use a orifice with a TXV.
    Apparently your rep doesnt carry it or you are not buying them but they make the BHC which can be ordered with a piston or TXV which matches with the 10 and most 12 SEER stuff, the BHK which is generally used in 12-14 SEER applications. Then the BHL, the BHM and the BHN. You're pretty much covered from 10-18 SEER. Maybe you need to revisit the spec sheets.

    The orifcace is used as a distributor when the TXV is installed. If you install it from a kit you need to replace the exsisitng piston with the new one. Now, in an upflow application you may find it doesnt make alot of difference in many cases but in a counterflow or horizontal, it can make a big difference.

    As for other brands, they also dont have as many circuits in their evaps as the multiflex has therefore they dont ned to address it quite the same. Sometimes I wonder why so many contractors want Rheem to copy other mfg's coil designs or want the air handlers to be larger when space constrants call for a low profile design. There is a reason for just about everything regardless of the brand.

  13. #13
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    Quote Originally Posted by docholiday View Post
    Apparently your rep doesnt carry it or you are not buying them but they make the BHC which can be ordered with a piston or TXV which matches with the 10 and most 12 SEER stuff, the BHK which is generally used in 12-14 SEER applications. Then the BHL, the BHM and the BHN. You're pretty much covered from 10-18 SEER. Maybe you need to revisit the spec sheets.

    The orifcace is used as a distributor when the TXV is installed. If you install it from a kit you need to replace the exsisitng piston with the new one. Now, in an upflow application you may find it doesnt make alot of difference in many cases but in a counterflow or horizontal, it can make a big difference.

    As for other brands, they also dont have as many circuits in their evaps as the multiflex has therefore they dont ned to address it quite the same. Sometimes I wonder why so many contractors want Rheem to copy other mfg's coil designs or want the air handlers to be larger when space constrants call for a low profile design. There is a reason for just about everything regardless of the brand.
    Because bigger coils have a lower pressure drop..........................................and are easier to clean.....................the multiflex totally sucks in all of it's design aspects, a complete POS......................I have also found that the piston becomes a restricter in an upflow application.............
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