I've asked around and had a look through a fair few text books and articles but can't seem to find an answer so here i go!

Say for instance i have a split system that's metered at the outdoor unit to and cooling and sent to the evap. What should be the temperature of the expansion line? (Not sure what the techincal name is for it as i believe it wouldn't be a liquid line.)

I've come across a fair few units that have only a very slight chill on this line at the outdoor unit. I would have thought because there is a much lower evaporating temp that the uninsulated line from the RMD + the stop valve assembly would have a nice chill to it.

Only thing i can think of is because of the warmer outdoor ambient air and that there is not enough heat exchange surface available between short line between the RMD (Outdoor) to the stop valve that it can't absorb to much heat and get nice and cold as it never seems to be insulated.

Any suggestions?