Dry magnetic flaw detector for scanning SMD-T pipes "SATURN"
Abstract
Dry magnetic flaw detector for scanning SMD-T pipes "SATURN"
Incoming article date: 21.09.2018The magnetic type of control is used to detect discontinuities (cracks, non-magnetic inclusions and other defects) in the surface layers of parts made of ferromagnetic materials and to reveal ferromagnetic inclusions in details from non-ferromagnetic materials. Methods based on the investigation of magnetic scattering fields after their magnetization have become widely used to detect discontinuities in the material of the base metal of pipes and welded joints of the main and auxiliary equipment of oil and gas producing complexes. In places of discontinuity, redistribution of the magnetic flux and a sharp change in the nature of the magnetic scattering field occur. The nature of the magnetic field of scattering is determined by the magnitude and shape of the defect, the depth of its occurrence, and its orientation relative to the direction of the magnetic flux. Surface defects such as cracks, oriented perpendicular to the magnetic flux, cause the appearance of the most pronounced magnetic scattering fields. Defects oriented along the magnetic flux practically do not cause the appearance of scattering fields. The review and analysis of existing external magnetic scanners - flaw detectors showed that when examining auxiliary equipment tubes for longitudinal and transverse defects, at least five scanner models - three for longitudinal and two for lateral scanners - should be available. As a result of the accumulated experience, the enterprise of LLC ""Antenor"", in Yoshkar-Ola, initiated scientific research to develop a competitive product that provides high operational efficiency of the main and auxiliary equipment of oil and gas production complexes on the basis of non-destructive technologies for monitoring the technical condition of pipeline transport. For this purpose, a prototype of a dry magnetic flaw detector (SMD) from a series of non-destructive testing instruments for magnetic flaw detection of metallurgical, construction and operational defects in the material of a pipeline element made of steel, its alloys and other ferromagnetic materials. Taking into account the peculiarities of the magnetic control of discontinuities in the surface layers of parts made of ferromagnetic materials, the main task in the design of the SMD-T ""SATURN"" was to provide a sufficiently powerful magnetic field capable not only to magnetize the pipe body, but also to provide sufficient force to hold the scanner at the object of investigation.
Keywords: pipeline, diagnostics, magnetic flaw detector, auxiliary equipment, gas and oil pipeline, prototype, testing, scanning, magnetic field