How to calculate Von Mises category combinations allowable using AutoPIPE?
Open respective combination User Code Combination dialog, as shown below:
Press the Help button in the lower right corner of the dialog, select the "Category" hyperlink, and review the Description for Von Mises.
"Von Mises stresses will be calculated for this combination. Stresses are ...."
Therefore, not allowable is automatically calculated, however one can override the Allowable stress, highlight the word Automatic on the Load combination dialog table for the respective Combination and enter a manual value to be used.
ASME B31.12 questions