Residual life assessment of T-piece of high temperature pipe

For the maintenance purpose the critical locations such as butt welds, T-piece pipe and so on are usually focused to assess the residual life of the steam pipe in power plants. In this study, two cases of the elastic stress evaluation for a T-piece pipe are performed to predict the residual life considering internal pressure and system load. Elastic-creep behavior is estimated in weld part in T-piece pipe and residual creep rupture life was also calculated using the stress analysis results. It was argued that the calculated life is reasonably same as the measured one. And the rupture reference stress are obtained by using R5 high-temperature assessment procedure to compare with the results of elastic-creep analysis. The results shows that rupture reference stress is a appropriate approach and can be reduced a conservative estimation and analysis time compared to the elastic creep analysis