Technical information / Tables and diagrams / Pressure classes
Table
PN · CLASS · K
Pressure class equivalents
Equivalents refer to matching connection dimensions; the allowable pressure depends on material and temperature.
Pressure scale
Classes of the three systems on one pressure axis (bar, logarithmic). ASME classes at the −29…38 °C rating of Group 1.1 carbon steel; PN and K classes at nominal pressure.
ASME Class ↔ PN
| ASME Class | ISO 7005-1 PNcurrent | Old DIN/ISO PNolder documents | Allowable pressureGroup 1.1, −29…38 °C, bar | Emsal page |
|---|---|---|---|---|
| Class 150 | PN 20 | PN 20 | 19.6 | ASME slip-on flange → |
| Class 300 | PN 50 | PN 50 | 51.1 | ASME slip-on flange → |
| Class 400 | PN 68 | PN 64 | 68.1 | — |
| Class 600 | PN 110 | PN 100 | 102.1 | ASME slip-on flange → |
| Class 900 | PN 150 | PN 150 | 153.2 | ASME slip-on flange → |
| Class 1500 | PN 260 | PN 250 | 255.3 | — |
| Class 2500 | PN 420 | PN 420 | 425.5 | — |
EN 1092-1 PN series
JIS B 2220 K classes
| Class | ≈ pressurekgf/cm² → bar | Emsal table |
|---|---|---|
| 5K | 4.9 | JIS B 2220 → |
| 10K | 9.8 | JIS B 2220 → |
| 16K | 15.7 | JIS B 2220 → |
| 20K | 19.6 | JIS B 2220 → |
| 30K | 29.4 | — |
| 40K | 39.2 | — |
| 63K | 61.8 | — |
Notes
- PN (nominal pressure) is roughly the allowable pressure in bar at 20 °C; as temperature rises the allowable pressure falls depending on the material (EN 1092-1 tables).
- Class is a designation, not a pressure value. A Class 150 carbon steel flange carries 19.6 bar up to 38 °C and about 13.8 bar at 200 °C.
- The ISO 7005-1 equivalents (PN 20, 50, 110 …) denote the same connection dimensions as ASME flanges. Older DIN/ISO editions used PN 64, 100 and 250 for Class 400, 600 and 1500, so these values may appear in older documents.
- The JIS K number is the approximate working pressure at ambient temperature (kgf/cm²); JIS flange connection dimensions differ from PN and Class flanges and are not interchangeable.
- Accuracy and currency are not guaranteed; use the current edition of the standard for design and purchasing decisions. How the library is compiled →
Related pages
| EN | EN 1092-1 slip-on flange · weld neck |
| ASME | ASME B16.5 slip-on flange · weld neck |
| JIS | JIS B 2220 slip-on flange |