Hoop Stress Allowable is 0.00 (zero) for a piping system analyzed per En 13480, why?
In AutoPIPE 09.05.00.14 and higher, a new feature was added CAE-CR-10281: Tools> Model Options>Result... "Use min(f;fcr) for Hoop".
As mentioned in the online help:
This option is only available for EN13480 European code.
A. When this option is checked, the program will use the minimum of time independent design stress f and time dependent stress fcr to calculated design stress for hoop.
B. When this option is unchecked, the program will use time independent design stress f as design stress for hoop.
See AutoPIPE online help for complete details on this feature:
Help > Contents> Search Tab> enter "Creep (fcr)" (include the quotes), press List Topics button, double click on the selected topic from the list provided to see more information.
In some models, an allowable value will only be calculated when this option is turned OFF..
En13480 Piping calculations