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A study of the reflection from discontinuities type notch in pipes with the fundamental torsional guided wave interaction is presented. Theoretical analyses of reflection coefficient for different size and position of notch in both direction in pipes are presented, and are estimated the influence on reflection coefficient of applied active focusing technique. The numerical calculations are performed with post processing method synthetic (passive) focusing technique using principles of Huygens and Fermat and Kirchhoff approximation. The analyses of reflection coefficient are researched according to the following factors: number of elements and there pitch size, nominal frequency, time delay (focal law), position and size of discontinuities.