Metric plastic pipe (PVC-U, PE) — the OD series

Metric pressure pipe in PVC-U (EN 1452) and PE shares one outside-diameter series; solvent and compression fittings grip the OD, so it is the number that identifies the pipe. Wall — and therefore ID — follows the pressure class (PN) or SDR, not the name.

A mystery 63 mm garden supply line is the single most-measured plastic size in Europe. For ID, measure a cut end or read the printed PN/SDR marking.