Study on application range of SIF calculation method for nozzle corner crack in pressure vessel for ASME XI code

Stress intensity factors (SIF) of a nozzle corner crack in a pressure vessel subject to pressure and thermal loadings are evaluated using finite element method (FEM) and compared with the method described in ASME XI appendix G (2013 section XI). The formula in ASME XI appendix G is defined for the crack corner at a specific location of the nozzle/vessel connection which may limit the structural integrity assessment of the pressure vessel under ever changing pressures and temperatures duty loads during heat-up and cool-down phases. Using FE method SIFs at corners of similar cracks assumed at other nozzle locations are then evaluated and compared with SIFs using ASME formula to assess the degree of conservatism.