I cut my fridge power by 75%. Really. No joke, no trick, no compromise.

[sailingharry]

Originally Posted by FlyingScot

The thin tubing is the high pressure liquid line (before expansion valve). The fatter tube is the low pressure liquid line (after expansion valve before evap plate).

Each evap plate has a line in and a line out. So if you see 3 lines, you need a 4th for the TXV sensing bulb. Real TXVs will have an additional line with a bulb attached to the outlet of evaporator plate, not leaving the box. This measures superheat (temp/pressure).

Sea Frost has other names for the valve, but they never use Thermal or TXV in the wording that I can find. They have a lot of documents on their website. Constant Pressure Valve is one of them you will see under the replacement parts section.
Please let us know what you find.

EDIT (complete delete of the post I just wrote....)
I thought there were 3 lines. Now, I'm not so sure. I need to go look at it again. Further, on re-reading the SeaFrost guidance that led me to making the adjustments I made, you are right -- they call it a "Constant Pressure Valve." In ways, it makes my changes make more sense, since it's not actually a TXV -- and if I was actually adjusting the low side pressure, it makes sense.



I need to go look at my system again.

[FlyingScot]

Originally Posted by sailingharry

EDIT (complete delete of the post I just wrote....)
I thought there were 3 lines. Now, I'm not so sure. I need to go look at it again. Further, on re-reading the SeaFrost guidance that led me to making the adjustments I made, you are right -- they call it a "Constant Pressure Valve." In ways, it makes my changes make more sense, since it's not actually a TXV -- and if I was actually adjusting the low side pressure, it makes sense.



I need to go look at my system again.

Literally adjust low side pressure with that valve. It takes effect immediately too. I wish I could see my gauges from the valve location as it would have saved me a lot of running up and down.

Good luck.

[rslifkin]

It seems to me like that valve is basically an adjustable orifice / capillary tube. Might not be quite as good as a TXV, but when making changes to the system design it's definitely better than a fixed orifice.

[sailingharry]

Mea Culpa

FlyingScot took issue with my understanding of the valve that I played with and discussed in my original post. He was right.

There are only 2 lines going to that valve -- high pressure, and low pressure. The third line, visible behind it, is the tie between two cold plates. With only 2 lines, it is impossible to be a TXV. It's just a set-able pressure relief valve.

Further, the behavior I witnessed is best explained by a pressure relief valve, and not a TXV. The TXV probably does NOT change the pressure (and boiling point) of the refrigerant -- as also pointed out by another poster upthread, it monitors superheat going into the compressor, another issue entirely.

The behavior and outcomes with the valve that I actually have match the explanation I was pontificating on. But the valve is most assuredly NOT a TXV as I initially thought.

I'm very content with the outcome of my fiddling. The temperatures and run times continue to be a huge improvement. But I am indebted to FlyingScot for accurately pointing out a significant error in my understanding of my system. In my days as a student at Navy Nuclear Power School, it would have been marked with a red "GCE" or Gross Conceptual Error.