Isn't she pretty? This is the expansion valve from my decrepit heat pump system. It's connected by flare connection from the liquid line. The other side is some sort of threaded fitting also. That connects to a distritubtor located on the other side of the metal housing. It has multiple smaller tubes connecting to various points on the coil. That distributor is 3/8" tube as well. However the flare nut is a different larger size hex. It bolts into the position where a piston control or orifice slug would fit as an alternative. The expansion valve was an upgrade for these systems years ago and was provided as a field installed kit.

This is in my heat pump/AC system. I believe it has a check valve so during heat mode gas can flow the alternate direction. I think that is why it has a second brass section and I'm thinking the bottom connection is between the two brass bodies is the alternate flow. I've looked online at Sporlan.com and downloaded their catalog of valves. I don't see any constructed in this manner. The part number is Y-930-3-VGA and Lennox appied their own tag LB57302DC. I believe the 3 in the number means 3 ton. It is installed in a 3-1/2 ton system.

My question is how to specify the replacement valve part number. I'm giving serious consideration to replacing the outdoor compressor or perhaps the entire outdoor condensor unit with one having 4 tons capacity. The indoor coil is rated for 4 tons cooling or I would go larger since my system is undersized.