Background: With the development and wide application of LBB technology

LBB can be applied on the pipe with known defects through aborative crack propagation analysis and deterministic LBB analysis.Purpose: Under this circumstance

some additional analysis are needed besides the traditional procedures required by SRP 3.6.3 and NUREG 1061.Methods: One of them is the analysis of the influence of off-center TWC on pipe LBB applicability.Results: In this text

three types of NPP high energy piping

whose nominal diameter is 6in

14in and 22in respectively

are chosen to be analyzed for the research of off-center TWC on pipe LBB applicability.First

the influence on COA is analyzed.Then the influences both on leakage crack size and on the maximum crack stable loads are analyzed.Conclusions: And finally the conclusions which can aid the LBB application on pipe with defect are presented.