A circular electromagnetic TE11-mode is used for detection of longitudinal crack in a stainless steel pipe. To show the capability of microwave nondestructive testing for detection of cracks in large and complex piping systems such as steam generator (SG) tube, inspected pipe including U–bend are examined in this study. The crack location is determined through time of flight (TOF) of the reflected wave and group velocity of electromagnetic signal. The TOF is evaluated in the time domain via Inverse Fast Fourier Transform (IFFT) of the wave spectrum. Then, two different methods of signal processing are applied to obtain TOF more accurately.