Device & Process for Controlling the Effectiveness of Particle Hammering of the Inner Surface of a Steam Generator Tube

Author:  Isnardon et al.
Source:  US Patent 4,893,490
Doc ID:  1988090
Year of Publication:  1988
Abstract:  
The hammering is carried out by a device having a tubular outer housing (5) which is placed against a face of the tube plate around a flush end of the tube to be hammered. A tool comprising a nozzle for projecting particles is mounted for axial movement in the outer housing (5). The control device has at least one piezoelectric sensor (20) in contact with the wall of the outer housing and apparatus for measuring (23, 24) the electrical signal generated in the sensor (20). The nozzle for projecting particles is introduced into the outer housing at the height of the sensors after each tube hammering operation. The electrical voltage of the signals produced by the sensors is measured.