When calculating the SIF for a bend with:
Nominal pipe size = 8.00 inch
Wall Thickness = .127
Bend radius = short (8.00 in)
Qual Stree = 40
Biaxial Type = 100% hand lay
SIF = 2.5
However, if the bend radius = Long (12.00 in), SIF is still the same, why?
Per code, ISO 14692-3:2002(E), section "D.2.2.3 Stress intensification factor (Sf )":
An upper limit, based on experience, is placed on all four Sf . No Sf shall be greater than 2.5.
Therefore SIF range is:
1.0 <= SIF <= 2.5.
Calculation of aforementioned bend exceed the SIF range set by the code, thus a 2.50 value was used instead.
Note: Remember that one can override the SIFs by Inserting a User SIF from the Insert>Xtra Data menu.
ISO 14692 code calculations
Bentley AutoPIPE