Required Thickness of Shell and Nozzle - PV Elite - Help - Hexagon

The software calculates the required thickness for the shell and nozzle as follows:

The joint efficiency used in this calculation is always 1.0. In 1989 we submitted a request for interpretation to the ASME Code in order to show that the use of 1.0 under all circumstances was justified. The reply was published in the A-90 Addenda as Interpretation VIII-1-89-171. The question and reply were as follows:

Question: In reinforcement calculations, is the joint efficiency used in calculating the required thickness of the vessel wall tr and the required thickness of the wall trn 1.0 regardless of the joint efficiency determined for the vessel wall and nozzle wall from the rules in UW-12, provided the nozzle does not pass through a weld?

Reply: Yes. Note also that the program takes into account the case where the nozzle passes through a weld by asking the joint efficiency of the weld, if any.