PN ↔ ASME Class Reference
Approximate comparison between EN PN ratings and ASME pressure classes.
Approximate engineering reference for comparing EN PN ratings and ASME pressure classes. Real compatibility depends on material group, design temperature, flange standard and piping code.
| ASME Class | Approx. Pressure Equivalent | Typical EN Piping Rating | Engineering Comment |
|---|---|---|---|
| #150 | ≈ PN20 | Usually paired with PN16 piping | Most common low-pressure process class |
| #300 | ≈ PN50 | Usually paired with PN40 piping | Very common refinery / API class |
| #600 | ≈ PN110 | Usually paired with PN100 piping | High-pressure process service |
| #900 | ≈ PN150 | Usually paired with PN160 piping | High-temperature / high-pressure service |
| #1500 | ≈ PN260 | Usually paired with PN250 piping | Heavy process applications |
| #2500 | ≈ PN420 | Usually paired with PN420 piping | Very high-pressure applications |
Important note
PN and ASME Class ratings are not directly interchangeable 1:1. Pressure capability depends on material, temperature and the governing standard such as ASME B16.5, EN 1092-1 and the applicable piping code. Always verify final compatibility for actual project conditions.