METHOD FOR MAGNETIC FLAW DETECTION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2017 - IPC G01N27/82 

FIELD: physics.

SUBSTANCE: method for magnetic flaw detection of steel pipelines from the inner surface, consisting in that a bipolar magnetisation system, providing axial magnetisation to technical saturation of the pipeline section between its poles, is moved along the inner surface of the pipeline, the signals, proportional to the induction of the magnetic scattering fluxes over the inner pipeline surface, are recorded by using the magnetosensitive elements, and the presence and parameters of the metal continuity defects in the pipeline wall are judged according to the aggregate of the received signals, wherein two pipeline sections, located with an axial clearance from the different sides against the plot magnetized by the main magnetization system, are magnetized by using two additional bipolar magnetization systems in the axial directions counter to the magnetization directions of the main magnetization system.

EFFECT: extending the scope of pipelines with a smaller internal diameter or a greater wall thickness.

2 cl, 6 dwg