WRC caln for stiffeners

In WRC calculation if the Nozzle is failing due to local loads specially in circumferential moment, practically we do provide 3 numbers of stiffeners to nozzle to restrict the moment but for checking in WRC, PvElite does not furnish any calculation to check whether by providing such stiffeners circumferential moment are in control.
please clarify.

Hello Anup

WRC 107 does not recognise any stiffeners as it is not included in the WRC 107 bulletin. You could perhaps try a re-pad, or a thicker re-pad. Perhaps the loads are just too great for the nozzle. You may have to go back to the piping engineer, and ask him to reduce the loads on the nozzle.

Thank you Mr. Ray_Delaforce,

In some cases, its fails after applying actual piping loads and most of the cases its failing in circumferential moments.
we all knew that to overcome this we shall take tha advantage of Insert Plate or use of higher Nozzle Thicknesses.

After considering all the above if it is failing then we have to provide stiffeners on nozzle to restrict that moment but pvelite does not shows any options for the stiffener's input and calculations for the same.

Both pressure vessel codes and WRC methods don't give calculation rules for the use of stiffeners, I think that's why this option is not available in PVElite. You can use general FEA for this.

Hello Anup

Really, the only way you can solve this is:

1 Use a thicker shell
2 Use a larger re-pad
3 Ask the piping engineer to reduce the loads at the nozzle connection.

There is not much else you can do.