ALLOWABLE STRESS BASIS IN VIII-2

In this example, under the creep range, the strength is taken as (YS @ design temp)/1.5

From Table Y-1 in ASME II-D, SA 387 GR 11 CL2 has a YS strength of 224 MPa @ 425C.

From Table 5A - @425C = 149 Mpa; @425C = 153 MPA ........ interpolated gives you an allowable stress of 149.8 MPa. NOTE that 224 Mpa / 1.5 ≈ 149 MPa

...... whoops ........ that should have been

From Table 5A - @425C = 149 Mpa; @400C = 153 MPA ........ interpolated gives you an allowable stress of 149.8 MPa. NOTE that 224 Mpa / 1.5 ≈ 149 MPa