Grade 11 High Temperature Steam Header Case History and Benchmark

The cost and complexity of design method validation at the component level makes actual and comprehensive benchmark cases challenging to obtain. This is especially true of elevated temperature design methods where component and material response is complicated by time-dependent creep and possibly creep-fatigue behavior. To support current Design-by-Analysis modernization development within Section I of the ASME Boiler & Pressure Vessel Code, service examples that are comprehensive enough to allow method validation, while still being tractable in complexity have been identified. To this end, the case history of a Grade 11 high temperature steam outlet header that was retired after 23 of years of service is presented. Detailed damage and deformation information is available which allows validation of creep material models, as well as future evaluation of candidate elevated temperature design method performance.