Is it now a days general practice to consider the External Loads coming on to Nozzles due to Piping in the WInd & Seismic Design of Tall Towers? If at all it is better to consider, what will be the usual sizes of Nozzle to be considered?

Hello Swamirao

The ASME code expects all loadings to be taken into account. This is stated in UG-22 of ASME VIII Division 1. The sizes of nozzles subject to external loadings are not stated in the code. The actual loads on each nozzle must be considered.

Generally, it is the normal practice to apply the various loadings (shear forces and moments) to the nozzle (or nozzles) in question, and then perform a local loading analysis in accordance with WRC 107 or PD 5500 Annex G to determine the local stresses generated in the shell at the nozzle location. This can be easily handled by CodeCalc (the Component Analysis section of PVElite).

Now, if you want the loads on nozzles to be considered transferred into the shell and supports, you will have to add the forces and moments in the PVElite model. However, the loads on the nozzles do not generally have a great effect on the axial stresses generated in the main shell of the vessel.

Best regards
Ray Delaforce