copper vs pvc compressor lines?

RustyRatRod said
When you start talking schedule this and that, I am way lost.

It's "what it's called." If you run into an older house with gal. pipe, it WILL be sked 40, that's about all that was used.

Sked 80 is thicker, more pressure, and uses heavier fittings, elbows, etc.

Who knows how the US got started down the road of pipe fittings, as they don't make sense to many people