I am analyzing some high yield piping to ASME B31.1 and am having trouble understanding the (non-liberal) allowable displacement stress calculated by CII.

The Material is (1)Low Carbon Steel, with Sc=332.267 MPa, Sh=322.0 MPa, f=1.0, and Sy=483.0 MPa.

I am expecting the Displ. Stress Range Allowable to be Sa=f(1.25 Sc + 0.25 Sh) = 495.83 MPa, but the allowable from CII is only 206.84 MPa (or 30 ksi). I would expect this value using B31.3, as in B31.3 Sc and Sh are limited to 138 MPa (20 ksi), but B31.1 has no such restriction on Sc and Sh.

Has anyone else run across this? Am I missing something, or does CII apply the B31.3 Sc and Sh limitations to B31.1 as well?