The FRP manufacturer provided the following allowables:

1500 psi for constant loads
3000 psi for occasional loads

I'm not familiar with the code compliance cases per BS 7159, but it seems that all load cases are compliance cases, with the exception of the Expansion cases.

So, how do I set up my load cases to account for the 3000 psi allowable? The SUS+WIND case is comparing the stresses to the 1500 psi allowable. Is that correct? Why isn't this considered to be an "occasional" case? B31.3 uses the typical 1.33*allowable, but this isn't right for FRP. (B31.3 isn't really appropriate for orthotropic materials anyway.)

Below is an example of how my load cases are set up. I've set up T2, P2 as the same design pressure and temperature (T1=T2, P1=P2), but the first case has a 1500 psi allowable and the second case has a 3000 psi allowable.

L1: W+T1+P1 (OPE)
L2: W+T2+P2 (OPE)
L3: W+P1 (SUS)
L4: W+P2 (SUS)
L5: W+T1+P1+WIN1 (OPE)
L6: W+T1+P1+WIN2 (OPE) {I have two wind directions}
L7: W+T2+P2+WIN1 (OPE)
L8: W+T2+P2+WIN2 (OPE)
L9: L5-L1 (OCC) (suppressed in output; construction case only)
L10: L6-L1 (OCC) (suppressed; construction case)
L11: L7-L2 (OCC) (suppressed; construction case)
L12: L8-L2 (OCC) (suppressed; construction case)
L13: L1-L3 (EXP)
L14: L2-L4 (EXP)
L15: L3+L9 (OCC)
L16: L3+L10 (OCC)
L17: L4+L11 (OCC)
L18: L4+L12 (OCC)

And I have other load cases for maximum restraint loads, too.

L1, L2: Operating cases
L3, L4: Sustained cases
L5: Operating (@T1, P1) + Wind (+X dir)
L6: Operating (@T1, P1) + Wind (+Z dir)
L7: Operating (@T2, P2) + Wind (+X dir) (should be same as L5, except has a different allowable)
L8: Operating (@T2, P2) + Wind (+Z dir) (should be same as L6, except has a different allowable)
L9 thru L12: These are construction cases only for use in the cases to follow.
L13, L14: Expansion cases
L15 thru L18: These are the SUS + WIND cases for each temp/press and wind direction.

I know a couple of these cases can be suppressed in the output. But what am I doing wrong? Why does the code compliance report still show the allowable in cases L15 - L18 as 1500 psi, not 3000? Is this because it's considered to be a sustained load and not an occasional case?

Please help!

Thanks.