A335 P22 Pipe MAWP Calculator ASTM A335 -P22 Alloy Steel Pipe SMLS 2 1/4Cr-1Mo
Material Properties Description
ASTM A335 -P22 Alloy Steel Pipe SMLS 2 1/4Cr-1Mo
Min Design Temperature
-20 °F
Y Coefficient
Ref 3 — Ferritic steels
Maximum Allowable Working Pressure (psig) Sch STD Sch XS Sch 160
NPS OD (in) 100 °F 200 °F 300 °F 400 °F 500 °F 600 °F 700 °F 800 °F 1/8 0.405 6,659 6,226 6,060 5,993 5,960 5,960 5,960 5,893 1/4 0.54 6,438 6,020 5,859 5,794 5,762 5,762 5,762 5,698 3/8 0.675 5,210 4,872 4,741 4,689 4,663 4,663 4,663 4,611 1/2 0.84 4,995 4,671 4,546 4,496 4,471 4,471 4,471 4,421 3/4 1.05 4,074 3,809 3,707 3,666 3,646 3,646 3,646 3,605 1 1.315 3,810 3,562 3,467 3,429 3,410 3,410 3,410 3,372 1 1/4 1.66 3,137 2,933 2,855 2,823 2,808 2,808 2,808 2,776 1 1/2 1.9 2,822 2,638 2,568 2,540 2,526 2,526 2,526 2,497 2 2.375 2,377 2,223 2,163 2,140 2,128 2,128 2,128 2,104 2 1/2 2.875 2,600 2,431 2,366 2,340 2,327 2,327 2,327 2,301 3 3.5 2,258 2,111 2,054 2,032 2,020 2,020 2,020 1,998 3.5 4 2,059 1,925 1,874 1,853 1,843 1,843 1,843 1,822 4 4.5 1,914 1,789 1,742 1,723 1,713 1,713 1,713 1,694 5 5.563 1,678 1,569 1,527 1,510 1,502 1,502 1,502 1,485 6 6.625 1,524 1,425 1,387 1,372 1,364 1,364 1,364 1,349 7 7.625 1,421 1,329 1,293 1,279 1,272 1,272 1,272 1,257 8 8.625 1,342 1,255 1,221 1,208 1,201 1,201 1,201 1,187 9 9.625 1,275 1,192 1,161 1,148 1,141 1,141 1,141 1,129 10 10.75 1,217 1,138 1,108 1,096 1,089 1,089 1,089 1,077 12 12.75 1,051 983 956 946 941 941 941 930 14 14 955 893 869 860 855 855 855 846 16 16 834 780 759 751 746 746 746 738 18 18 740 692 673 666 662 662 662 655 20 20 665 622 605 598 595 595 595 589 22 22 604 565 549 543 540 540 540 534 24 24 553 517 503 498 495 495 495 489 26 26 510 477 464 459 456 456 456 451 28 28 473 442 431 426 424 424 424 419 30 30 441 413 402 397 395 395 395 391 36 36 367 343 334 331 329 329 329 325 42 42 314 294 286 283 281 281 281 278 44 44 300 281 273 270 269 269 269 266 46 46 287 268 261 258 257 257 257 254 48 48 275 257 250 247 246 246 246 243
Allowable Stress vs Temperature 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 1000 1100 1200 Temperature (°F) 0 5 10 15 20 Allowable Stress (ksi) Disclaimer: This calculator is for guidance only. Results are based on ASME B31.3-2024 allowable stresses for seamless pipe (Ej=1.0, W=1.0). Always verify against the current edition of the standard. The engineer of record is responsible for all design decisions.
References ASME B31.3-2024 — Process Piping, Table A-1 ASME B36.10M — Welded and Seamless Wrought Steel Pipe ASME B16.5-2020 — Pipe Flanges and Flanged Fittings 
