Will a R7 Tvx work in my r22 system?
 

Ok, you guessed it, I bought a nice 1/2 ton Tvx at the local junk sale for $3 to use in my r22 ground water 3/4 ton heat pump water heater (former window unit) and didn't notice it was for R7. Yes it is old, built like we used to build stuff!
Should I try it?

To my knowledge, there is no refrigerant designated as R-7.

You paid your money, so why not give it a try.

Stand well back from the machine for your first run.

-AC

Oops, meant R12
 

Sorry AC, i think the culprit may be age and kids, but I meant will a R12 txv work in an R22 system?

The bulb in the TXV is filled with the refrigerant it is meant for. So your bulb would be filled with R-12.

It will have a different curve than R-22, and will not work as well, but if your expectations are low... it might work for you.

If you're tying to get the best out of your equipment, maybe you should give ebay a try and get the proper part for maybe $30... maybe less.

-AC

Sporlan EGV 1 2 C 5638275 1 2 Ton TXV 5" Cap Tube with Clamp R 22 150302 | eBay

http://www.ebay.com/itm/ALCO-BAEB1-2...EAAOxyOlhS1sXw

Thanks!
 

Thanks guys, i'm convinced! It's tough enough to figure this system out without also trying to make R12 act like R22!

That r12 txv will not work well with r22 or propane. Its operating pressure will yield way too little mass flow, just like a cap tube that is too Long. It will work well with r134, though.

I found a cheaper txv on eBay, from surplus city liquidators:
SPORLAN EGV-1-C/5638276 1 TON TXV 5' CAPILLARY TUBE WITH CLAMP 40944

They sell good stuff for dirt cheap and also combine shipping. I have had good dealings with them. They ship fast, too.

I hate when shipping is as much as the part cost. lol But that does look like a good deal! Would a 1 ton be close enough to work with a half ton compressor?

Not a perfect match, but it would work a whole lot better than a cap tube sized for 1 ton. It would probably work better than a properly sized cap tube.

A good place to find super cheap R12 or R134 TXV's is your local pull-a-part salvage yard. Lots of the newer cars have TXV's in them instead of a fixed orifice. Pretty much all of the vehicles equipped with rear air have a TXV-metered evaporator airbox in the rear quarter panel someplace. The windstar/freestar/freestyle minivans even have flare fitting connections. the whole shebang is made to be removed with just a few screws. I bet they would dominate if paired up with a larger refrigerator compressor/condenser that draws around 400 watts at load.

I agree, considering the hassle and level of work involved in a TXV swap, pick up the correct valve for your build. Maybe your system will work, but it will never reach peak efficiency with the wrong TXV. You'll pay back the cost in higher electric bills most likely.

I think I paid just about $35 with shipping for each of two 4 ton R-410A TXVs I purchased in the spring.

If / when you go looking, keep in mind that in the Parker / Sporlan language, the V in the end of the part designation is R-22 while a Z at the end is R-410A.

For example, I am using a CBBIZE-4-GA model. The Z means it's R-410A and the 4 means it's a nominal 4 ton valve. The CBB denotes the revision / design style. CBB happens to be an older design.

I've attached 3 documents from Parker/Sporlan that I came across while designing and building my heat pump... I hope that 2 of them may help you, while the R-410 document might help the next guy who happens across this post.