[Richard]

I recently had to replace one of the compressors in a SCS basement unit. After compressor replacement, the unit did not function well, and the existing thermal expansion valve TXV was the suspected culprit. 

The original valve is obsolete and was a custom OE made for SCS. Lovely, now it's made of unobtanium.  

I ended up using a type of TXV that uses a Sporlan EQBODY 3812 OD STR, a QC2 168074 cartridge, and  KT NGA 43 Power Element. 

Huh?  The reason for so many part numbers it the valve I used  can be configured in many different ways. All that sounds like goobly gook, but your AC tech can use that info at the local AC supply place to get a replacement valve. 

What you are looking for is a one ton, internally equalized valve, sweat fittings for R 22. 

The above configuration worked great with the unit specified charge of 36 OZ of R22. It produced 10 degrees of supercool (perfect). 

I had to do a bit of plumbing work to fit it in the unit because the configuration of the inlet and outlet plus the size of the outlet is different than the original. 

   

[Richard]

I experienced a slight problem with the expansion valve list above that did not manifest itself on the bench, but only showed up after an extended run in the coach. The valve above does not appear to bleed the pressure between high side and low side after the compressor turns off. This results in the compressor trying multiple times to start against too high of a head pressure. This is not good for the compressor.

I found another valve that does work well, and is much much cheaper.




EMERSON/ALCO HFSC 1 HC/057468 1 TON ADJUSTABLE INTERNAL MEDIUM-TEMP TXV
EMERSON/ALCO HFSC 1 HC/057468 1 TON ADJUSTABLE INTERNAL MEDIUM-TEMP TXV