Typical liquid temperature for txv selection

[kengineering]

Hi,
It sounds simple enough however when using a TXV selection program there are tipping points that change the valve and orifice size if inputting different liquid temperatures.
So;
I sometimes don't have the info at the time of production therefore for a supermarket rack with a heat exchanger just before the valve I will generally use 70°f (21°C) as my liquid temp for valve selection. Any thoughts?

Thanks, Ken

[RANGER1]

Ken,
I would have thought you would be indicating amount of liquid line subcooling to make selection. Delta p across valve important & would have thought 2-5 deg C subcooling at inlet of TX valve.
Saturated condensing pressure of 25 deg C seems low, so you would look at possible minimum & maximum ambient temperatures to help selection as well.
Liquid/suction line heat exchanger would not guarantee amount of subcooling though.
Have you any feedback on previous selections?

[kengineering]

Ranger 1, I've been selecting TXV's this way for many years without issue. However I'm working with a new installer who believes one of our selections should be larger which led to re-running the numbers research and this inquiry.

Thanks for the feed back I'm sure more will be revealed.

Ken

[Brian_UK]

Sporlan documents 10-9 and 10-10 provide the correction factors to be applied to different liquid temperatures. Their baseline is 100°F.

Download here http://sporlanonline.com/literature-and-educational-materials/thermostatic-expansion-valves/

[RANGER1]

Ken,
No worries, of course a number of ways to cross check things.
After seeing Brians post I found this youtube link.
We probably use Danfoss exclusively & they ask for different things than some others.

https://www.youtube.com/watch?reload=9&v=LIFEQUUru4w

[kengineering]

Thank you Brian_UK, I use the Sporlan Product Selection Program. Great tool.

Ken