DEVICE FOR LOCAL DEMAGNETISATION OF PIPELINES Russian patent published in 2010 - IPC H01F13/00 

FIELD: physics.

SUBSTANCE: device for local demagnetisation of pipeline elements consists of a demagnetising cable powered by direct current from a welding rectifier and designed in the form of a multiturn coil connected by connectors lying in a metal framework, on which sensors of magnetic field magnitude and direction are mounted on both sides of a weldable seam, and current is fed through a control unit which is incorporated in a system for feedback coupling with said magnetic field sensors, the metal framework consists of an open ferromagnetic magnetic circuit with a coil inside, pole-pieces and nonmagnetic plates in form of pipes, alternately situated with respect to the magnetic circuit, wherein said pole-pieces are in form of a five-star mechanism on hinges with control of the diametre of the lower cylindrical surface in the range from 325 to 1420 mm and on supports with a magnet lock which can be made in form of magnetic wheels with axial direction of magnetisation.

EFFECT: enhanced operation of the device for pipes with different diametres while providing good quality of local demagnetisation.

2 cl, 3 dwg