Nozzles in the knuckle region of a torispherical head: stress levels and load interaction effects

The results of a limited parametric study on the stress levels in knuckle e ncroaching nozzles in a Klopperboden torispherical head due to pressure and nozzle loads are presented. The results give support to the CEN TC 54 proc edure which requires thickening of the :knuckle region for such nozzles for pressure loading. Stress levels due to nozzle loads are shown to be of the same order of magnitude as those in the equivalent axisymmetric nozzle. St udies of interaction diagrams have confirmed the CEN TC 54 proposal for com bined loading in axisymmetric nozzles but have shown that a linear interact ion rule should be recommended for non-axisymmetric nozzles in heads.