A312 TP304 Pipe MAWP Calculator ASTM A312 TP304 SS Pipe Smls 18Cr-8Ni
Material Properties Description
ASTM A312 TP304 SS Pipe Smls 18Cr-8Ni
Min Design Temperature
-425 °F
Y Coefficient
Ref 4 — Austenitic 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 6,659 6,659 6,193 5,827 5,527 5,261 5,061 1/4 0.54 6,438 6,438 6,438 5,987 5,633 5,344 5,086 4,893 3/8 0.675 5,210 5,210 5,210 4,845 4,559 4,324 4,116 3,960 1/2 0.84 4,995 4,995 4,995 4,646 4,371 4,146 3,946 3,797 3/4 1.05 4,074 4,074 4,074 3,788 3,564 3,381 3,218 3,096 1 1.315 3,810 3,810 3,810 3,543 3,333 3,162 3,010 2,895 1 1/4 1.66 3,137 3,137 3,137 2,917 2,745 2,604 2,478 2,384 1 1/2 1.9 2,822 2,822 2,822 2,624 2,469 2,342 2,229 2,145 2 2.375 2,377 2,377 2,377 2,211 2,080 1,973 1,878 1,807 2 1/2 2.875 2,600 2,600 2,600 2,418 2,275 2,158 2,054 1,976 3 3.5 2,258 2,258 2,258 2,099 1,975 1,874 1,783 1,716 3.5 4 2,059 2,059 2,059 1,915 1,802 1,709 1,627 1,565 4 4.5 1,914 1,914 1,914 1,780 1,675 1,589 1,512 1,455 5 5.563 1,678 1,678 1,678 1,560 1,468 1,392 1,325 1,275 6 6.625 1,524 1,524 1,524 1,418 1,334 1,265 1,204 1,159 7 7.625 1,421 1,421 1,421 1,321 1,243 1,179 1,123 1,080 8 8.625 1,342 1,342 1,342 1,248 1,174 1,114 1,060 1,020 9 9.625 1,275 1,275 1,275 1,186 1,116 1,059 1,008 969 10 10.75 1,217 1,217 1,217 1,132 1,065 1,010 962 925 12 12.75 1,051 1,051 1,051 977 920 872 830 799 14 14 955 955 955 889 836 793 755 726 16 16 834 834 834 776 730 692 659 634 18 18 740 740 740 688 647 614 585 562 20 20 665 665 665 618 582 552 525 505 22 22 604 604 604 562 528 501 477 459 24 24 553 553 553 514 484 459 437 420 26 26 510 510 510 474 446 423 403 388 28 28 473 473 473 440 414 393 374 360 30 30 441 441 441 410 386 366 349 335 36 36 367 367 367 342 321 305 290 279 42 42 314 314 314 292 275 261 248 239 44 44 300 300 300 279 263 249 237 228 46 46 287 287 287 267 251 238 227 218 48 48 275 275 275 256 241 228 217 209
Allowable Stress vs Temperature 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 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 
