ASME Piping Code-Based Stress Analysis Procedure and a Comparison With the Italian Code

The procedure proposed applies to evaporator section of bottom-supported heat-recovery steam generators (HSRG): It includes classical methods for the static analysis of the lower header based on ASME Power Piping code B31.1 [1] and a computer-modeled flexibility analysis with a preliminary stress evaluation using both Italian and ASME pressure formulae. The stability of the harp high-temperature components may be critical because of their longitudinal dimensions, thermal expansions and loading. So, further elements of engineering choices may help obtaining good design of the header-tube assembly (harp).