I have a pipeline with local a diameter of 2463 mm and a wallthickness of 531.5 mm (local stiffened rings to influence positive ovalisation in the pipe at the miter bends). The diameter/wallthickness ratio is 2463/531.5 = 4.634

This is lower then 5, so no calculation is done for DF 6.1. According to the changelogs this error check is new in v4.4.0.

Better is to do also 3D stress calculation for thick-walled pipes (Dgem / d < 20, see article 8.5.2.1 NEN 3651:2012) given by this formulae:

(Source: D.3.1.1 NEN 3650-2:2012)

Ple4Win does only a 2D stress calculation with this formulae, which is normal for thin-walled pipes (Dgem /d ≥ 20, see article 8.5.2.1 NEN 3651:2012):

(Source: D.3.1.1 NEN 3650-2:2012)

A wish is to give a warning instead of an error for the hardcoded limit Diam/wallth < 5 for a 2D stress calculation, because in the previous version v4.3.1 this was allowed or allow a 3D stress calculation given by the first formulae above. As a workaround I have to calculate this project with Ple4Win v4.3.1.

I have addded the project file for this case.