The purposes of this study is R/D Tech gratitude TC-5700 system used as an inspection device, purobu uses a representative inner insertion formula coil. Various defects of an installed cylinder thermal exchanger were processed into a regular shape and arrangement tube in the shell inside that was pressure courage. I carried out a test about expanding zone test sample and considered possibility of the defect detection, because a stress corrosion crevice and the same defect cannot forecast a crevice growth speed, cause leakage of a thermal exchanger, and large in quality of a production product can affect it. I was able to evaluate the detection of a circumference direction defect and size of a defect in the tube which did not get expanding zone rolling done comparatively exactly.