It is optional to include corroded wall thickness, axial force and torsion in the DNV stress calculations, what should I use?
Yes for the DNV code, the program defaults to Use nominal thickness = checked, since this code explicitly uses nominal thickness for stress calculations. However other codes default to use corroded thickness for stress calculations which is more conservative. i.e for longitudinal pressure stress and corroded section modulus used in bending stress calculations. Refer to the following help topic for code calculations. Autopipe 6.X “Online help topic Autopipe Reference information / Code Compliance Calculations/ DNV” By default axial force and torsion effects are NOT included for DNV but it is recommended to include them for offshore risers especially when the line pressure is high e.g > 500psi. To include axial force and torsion check the following options.
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