Flaw detector for pipe employing magnets located outside the pipe and detector mounted inside and movable along the pipe with the magnets

摘要

A detector for magnetically detecting flaws on the inner surface of a pipe of magnetizable material comprises a magnetizing assembly having exciting magnets and movable longitudinally along the interior of the pipe and a detecting assembly movable longitudinally along the exterior of the pipe. The magnetizing and detecting assemblies are opposite and close to each other through the wall of the pipe and movable longitudinally of the pipe in a synchronized manner to ensure highly accurate flaw detection.