There are circumstances (especially for openings reinforced by external pads) when the "weakest" component of the shell-nozzle junction is the NOZZLE.

WRC 107 method cannot handle this case since this calculation procedure is dedicated to stress concentration assessment for the shell wall only.

Therefore, when the allowable loads (that would have been specified by the vendor) are not available and the Finite Element Analysis approach (such as FE Pipe) cannot be employed, WRC-297 method is the most suitable analytical approach because the both NOZZLE and SHELL maximum secondary and peak stresses are quantified.

Regards,