02. SIF calculations at TEEs are all the same when analyzed per EN13480 -2012 piping code in AutoPIP

Applies To
Version(s):2004, XM, V8i 
Area: Calculation
Original Author:Bentley Technical Support Group
Date Logged
& Current Version
Mar. 2015


In EN 13480-3:2012 Table H.3, SIFs are defined depending on the type of tee. Welded-on fitting, contour insert, extruded welding tee, and unreinforced fabricated tee all have different flexibility factors and therefore different SIFs. However, except for the contour insert, AutoPIPE reports the same SIF for all cases (4.948). This SIF is higher than I calculated based on Table H.3 (see attached). Please let me know whether this is correct behavior for the software, and if it is correct, and if it's not too much trouble, please explain what I'm doing wrong in my sample calculation.


AutoPIPE is working correctly. 

Please see the following AutoPIPE help section:

Help > Contents> Contents Tab> Reference Information> Code Compliance Calculations> Euro En 13480 (2002)> (2002) Flexibility and Stress Intensification Factors. 


1. AutoPIPE help was not updated when both 2010 and 2012 sections were added. This SIF information applies to all En13480 editions and will be updated with the same information in a future version.

2. This "Single SIF at point" setting can be found under, Tools> Model Options> Results> 

Notice how this setting significant affects the SIF calculations:

3. Type = Contour, Extruded, and Fitting are not explicitly mentioned in the piping code H1 table as clearly depicted in table H3. Therefore, AutoPIPE uses the same calculation for Unreinforced Tee SIF values when "Single SIF at point" option is enabled. 

See Also

En13480 Piping calculations

Bentley AutoPIPE