Group 2.1 Pressure-Temperature Ratings
Standard-carbon austenitic stainless steels. They start lower than carbon steel at ambient but hold their rating far better above 800 °F.
- Standard
- ASME B16.5
- Group
- Group 2.1
- Materials
- A182 F304, A182 F316, A312 TP304, A312 TP316, A240 304/316
- Class 150 at 100 °F
- 275 psig (19.0 bar)
- Class 150 at 600 °F
- 140 psig (9.7 bar)
| Class | 100 °F | 200 °F | 300 °F | 400 °F | 500 °F | 600 °F | 650 °F | 700 °F | 750 °F | 800 °F | 850 °F | 900 °F | 950 °F | 1000 °F |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Class 150 | 275 | 235 | 215 | 195 | 170 | 140 | 125 | 110 | 95 | 80 | 65 | 50 | 35 | 20 |
| Class 300 | 720 | 620 | 560 | 515 | 480 | 450 | 445 | 430 | 425 | 415 | 405 | 395 | 385 | 360 |
| Class 400 | 960 | 825 | 745 | 685 | 635 | 600 | 590 | 575 | 565 | 555 | 540 | 525 | 510 | 480 |
| Class 600 | 1440 | 1240 | 1120 | 1025 | 955 | 900 | 885 | 865 | 845 | 830 | 810 | 790 | 770 | 720 |
| Class 900 | 2160 | 1860 | 1680 | 1540 | 1430 | 1350 | 1330 | 1295 | 1270 | 1245 | 1215 | 1180 | 1155 | 1080 |
| Class 1500 | 3600 | 3095 | 2795 | 2570 | 2385 | 2250 | 2215 | 2160 | 2110 | 2075 | 2020 | 1970 | 1930 | 1800 |
| Class 2500 | 6000 | 5160 | 4660 | 4280 | 3975 | 3750 | 3690 | 3600 | 3520 | 3455 | 3370 | 3285 | 3215 | 3000 |
Interpolation between listed temperatures is permitted; extrapolation is not.
Common questions
Which materials are in ASME B16.5 Group 2.1?
A182 F304, A182 F316, A312 TP304, A312 TP316, A240 304/316.
What is a Class 300 Group 2.1 flange rated at 600 °F?
450 psig (31.0 bar). At 100 °F the same flange is rated 720 psig (49.6 bar).