copper vs pvc compressor lines?

You mean size? All same "nominally." that is 3/4 PVC is "same" as 3/4 black. Black / galvanized varies a little in size, and sked 40 vs of course sked 80 is thicker wall, so smaller ID with sked 80

Sked 40 PVC is fairly close to sked 40 black/ galvanized. The "200" stuff is quite a bit thinner.