[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The original valve is obsolete and was a custom OE made for SCS.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.