Group 1.2 Pressure-Temperature Ratings
Carbon and carbon-manganese steels with a slightly lower allowable stress than Group 1.1, including the low-temperature impact-tested grades.
- Standard
- ASME B16.5
- Group
- Group 1.2
- Materials
- A350 LF2 Cl 1, A203 Gr B, A516 Gr 65, A537 Cl 1
- Class 150 at 100 °F
- 265 psig (18.3 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 | 265 | 250 | 230 | 200 | 170 | 140 | 125 | 110 | 95 | 80 | 65 | 50 | 35 | 20 |
| Class 300 | 695 | 655 | 640 | 620 | 605 | 570 | 550 | 530 | 505 | 410 | 270 | 170 | 105 | 50 |
| Class 400 | 925 | 875 | 845 | 825 | 805 | 755 | 730 | 710 | 675 | 550 | 355 | 230 | 140 | 70 |
| Class 600 | 1390 | 1310 | 1265 | 1240 | 1205 | 1135 | 1100 | 1065 | 1015 | 825 | 535 | 345 | 205 | 105 |
| Class 900 | 2085 | 1965 | 1900 | 1860 | 1810 | 1705 | 1650 | 1600 | 1520 | 1235 | 805 | 515 | 310 | 155 |
| Class 1500 | 3470 | 3270 | 3170 | 3095 | 3015 | 2840 | 2745 | 2665 | 2535 | 2055 | 1340 | 860 | 515 | 260 |
| Class 2500 | 5785 | 5450 | 5285 | 5160 | 5025 | 4730 | 4575 | 4440 | 4230 | 3430 | 2230 | 1430 | 860 | 430 |
Interpolation between listed temperatures is permitted; extrapolation is not.
Common questions
Which materials are in ASME B16.5 Group 1.2?
A350 LF2 Cl 1, A203 Gr B, A516 Gr 65, A537 Cl 1.
What is a Class 300 Group 1.2 flange rated at 600 °F?
570 psig (39.3 bar). At 100 °F the same flange is rated 695 psig (47.9 bar).