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Thread: Wrong TXV

  1. #1
    Join Date
    May 2012
    Location
    Mayfield, KY
    Posts
    39

    Wrong TXV

    Hello guys! This is my first thread here, I have been reading for a while though. I'm just gonna jump right in.

    The company has recently let a tech go and I am in his area working until we hire a replacement. i have been working on closing out some of his open work orders and I came across this today.

    Trane THC036
    The guy had ordered a cfm and I was there replacing it when I noticed the compressor was unplugged. I checked it before applying power and found open windings. This led me to really look the unit over. If you knew this guy you would have done the same. I noticed that the TXV didn't quite look right and upon further investigation I found that it is a Sporlan SVE-4 with a 83 VGA power cap. I know this is a 4 ton txv and my question is, I there enough adjustment to make it work with my 34,000 btu compressor or do I need to get the right one?

    Please don't be too mean to me. hahaha

  2. #2
    Join Date
    Apr 2003
    Location
    Maple Grove, MN
    Posts
    1,245
    I'm not much of a TXV expert, so hopefully someone smarter than me will chime in later, but I know that some Sporlan valves have replaceable cartridges inside that you can mix and match to make different capacities. If this is one of those types of valves, you could get the right cartridge to make it a 3 ton.

    Having said that, this might be an alright valve as is and maybe you could leave it alone, but, it also might be the reason the compressor went bad. Since you'll have the system empty anyways to change out the compressor, I wouldn't want to take the chance on leaving it. Unless, that is, someone smarter than me chimes in shortly to say it's alright.

  3. #3
    Join Date
    Nov 2005
    Posts
    1,350
    Yes you can change the insides and make up what you want. Just make sure the power head is for what you want. I have seen freezer power heads on refrigerators, and the right refrigerant is a must. I had a 404 txv running 134a.
    I STARTED WITH NOTHING, AND I STILL HAVE MOST OF IT!

  4. #4
    Join Date
    Oct 2011
    Location
    Springfield, Missouri
    Posts
    18
    Sporlan valves are my love lol they are all I use. So do you know what body style and the input and output sizes and internal or external balance and what color is on your power head also I do have my ref. sheets I can turn into a PDF if you need it. They ID these valves quickly and give you the charge and ref. type color codes and every possible ID marking that will be on the body and the head

  5. #5
    Join Date
    May 2003
    Location
    Utah
    Posts
    718
    Quote Originally Posted by hvacguy99 View Post
    Hello guys! This is my first thread here, I have been reading for a while though. I'm just gonna jump right in.

    The company has recently let a tech go and I am in his area working until we hire a replacement. i have been working on closing out some of his open work orders and I came across this today.

    Trane THC036
    The guy had ordered a cfm and I was there replacing it when I noticed the compressor was unplugged. I checked it before applying power and found open windings. This led me to really look the unit over. If you knew this guy you would have done the same. I noticed that the TXV didn't quite look right and upon further investigation I found that it is a Sporlan SVE-4 with a 83 VGA power cap. I know this is a 4 ton txv and my question is, I there enough adjustment to make it work with my 34,000 btu compressor or do I need to get the right one?

    Please don't be too mean to me. hahaha
    No, the S valve is not a replaceable cartridge style TEV.

    The non balanced ported TEV can modulate down to approximately 50% of it's rated capacity, so the SVE-4-VGA will be ok at a full load condition. It is the reduced load condition that might be a problem.

    If this unit were operating in the fall or spring with a reduced load of 24,000 Btu, this puts the SVE-4 at the ragged edge of being able to control the superheat set point, and possibly straying into a flood back condition....not good for your customer or his compressor.

    It isn't a good idea to start replacing internal parts in an attempt to change capacity. There is always the issue of pushrod length when changing parts...if it's too long you will increase valve capacity; too short and you decrease valve capacity.

    There is also the potential for the converted valve not being properly identified, leaving the valve's true capacity a mystery.

    Best to change the valve.

    The post which mentioned an R-404a valve being converted to an R-134A valve was likely the result of a power assembly change. With a given port size the capacity will vary depending on the refrigerant used. This is a function of the thermodynamic properties of the refrigerant. Changing the power assembly will allow the valve to be used for a different refrigerant. Same internal parts and different capacity due to the change in refrigerant.

  6. #6
    Join Date
    Apr 2012
    Location
    New York City
    Posts
    52
    T&C... If you have time... I'd be interested in seeing those PDFs! Thanks!

  7. #7
    Join Date
    May 2012
    Location
    Mayfield, KY
    Posts
    39
    I thank you guys for the advice. I did just go ahead and replace the tev while I had the system down. It only made sense. It was a little bit of a challenge since it was a hacked retrofit to begin with. But, in the end, I had a perfectly working system.

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