It is opinion that WRC-297 should be not applicable to check stresses at nozzle reinforcing pad edge, but WRC-107 must be used at that location. This because a main requirement of WRC-297 theory applicability is to have a penetrated shell, with a nozzle neck penetrating and attached to the shell by a through penetration weld. All the parameters to be used for WRC-297 curves to be selected are related to a nozzle thickness and on said assumption. Since WRC-107 consider an un-penetrated cylindrical shell and a "round attachment", this Code should be used to check stresses at reinforcing pad edge.
Why, and on which assumptions (where is a "nozzle thickness" on a pad ?), PVElite goes for WRC-297 at pad edge ? Since stresses on shell and on nozzle neck are related together, why a pad is considered like a thick nozzle neck ?

Dear Giorgio,

Both WRC 107 and 297 does not address re-pad. In both cases we (and many other software vendors) add the consideration of the re-pad by modifying/extending the applicability of these bulletins. So, that the user has some answers in case they have a re-pad.

So, as a user you should be aware of assumptions that the software makes. You have a good point. That is why I recommend that users run both WRC 107 and 297 analysis. If it is critical application and if the actual stress is close to allowable stress and if your geometry is lot outside the range of these bulletins, you should look at finite element analysis.