Study On Lifetime Evaluation Methods Of Flaw In Npp Process Piping

Study on evaluation methods and process of piping flaw based on ASME Code Section XI Appendix C “Evaluation of Flaws in Piping”, especially on the most important step “flaw extension”. Finite element software is applied to simulate the linear elastic flaw extension. The relationship between the loads and flaw extension characteristics is obtained. An alternative calculation methods of flaw extension which is more accurate is generated. In addition, extension characteristics of the through wall crack and the piping which R/t is greater than 20 are preliminary studied.