Complete A/C rebuild Q

Thanks Redfish, I have a new expansion valve so no worries on little parts. :)
and yeah the copper lines seemed a little fragile.

The pic shows the old valve installed. little L shaped thing with 2 copper lines from it. the bottom one is the one in question. it has no threads or anything and when I pulled on it, it just came right out. That thing should be sealed right? otherwise the system cant hold pressure, right?

I had just planned on putting it together the way it came apart but it doesn't seem right.
Thanks