Flanged end modifications
Modifications resulting from flanged ends are permitted in the code providing the bend is not a widely-spaced miter.
Calculate stress intensification factors (SIFs) for intersections
In-plane and out-plane SIFs for intersections are separate and unique.
B31.3 Chapter IX adds the F/A longitudinal stress components and torsion to the code stress component for all stress categories.
Girth butt welds default value
The default SIF value for a girth butt weld is 1.0. This is also Markl’s original basis for SIFs.
Calculate socket welds
B31.3 Chapter IX makes no distinction between socket welds with undercut and socket welds without undercut. Unless you are specifying a fillet weld leg length, use a default SIF value of 1.3 for all B31.3 Chapter IX socket welds.
B31.3 2014 uses 1.3 for socket welds with no undercut. The software provides 2.1 as a legacy value for calculations based on earlier versions.
Calculate the stress allowables
Use the equations below to calculate the stress allowables.
Expansion Allowable = 1.25Sc+0.25Sh
Sustained Allowable = Sh
Occasional Allowable = Sh * (Occ)
Where:
Sc = Cold Allowable Stress
Sh = Hot Allowable Stress (as selected)
Sl = Sustained Stress
Occ = Occasional Load Factor Default is 1.33
Calculate corroded stress
By default, B31.3 Chapter IX applies corrosion to section modulus calculations for sustained and occasional stress calculation. Specifying All Stress Cases Corroded in the setup file performs the corroded stress calculations for all stress calculations.
Reducer default values
The default SIF value is 1.0. The default flexibility factor value is 1.0.