Jadnashua
Retired Defense Industry Engineer xxx
Copper tubing is sized by the external dimension...as you get heavier gauge copper tubing, only the ID changes as the wall thickness increases...not the OD. Because the OD stays the same size, you can use the same fittings to make connections, regardless of whether you're using type K, L, or M rigid copper tubing.
Plastic pipe like CPVC an PEX also have the same OD, but because they are quite a bit weaker, the ID is much smaller. Some of the other plastic tubing, the id stays the same, and the thickness varies based on the type of plastic and the pressure rating it achieves...higher pressure ratings typically need thicker.
Plastic pipe like CPVC an PEX also have the same OD, but because they are quite a bit weaker, the ID is much smaller. Some of the other plastic tubing, the id stays the same, and the thickness varies based on the type of plastic and the pressure rating it achieves...higher pressure ratings typically need thicker.