A finite element stress analysis of an aftercooler header box was performed.  The boiler was analyzed and the results compared to the ASME Section VIII Division 2 criteria (2004 Edition with 2006 Addenda) for stress.  The loads analyzed were design internal pressure and hydrostatic test pressure.  the complex shape of the nozzles, and the way the inside of the nozzle is flush with the inside of the header box presented a challenge for meshing.

Results of the analysis predict that the vessel conforms to the allowable limits for stress according to criteria set forth in Mandatory Appendix 4 of Section VIII, Division 2 of the Code, using Division 1 stress values.