The defectoscopes -- "intelligent pigs" of KOD-4M-1420, 1220 types are realizing the method of transverse magnetization of gas pipelines parts to provide the detection of longitudinal stresscorrosion cracks.The measuring-transforming system helps to obtain the space distribution of discrete magnetic field near the internal gas pipeline surface. This function contains the information about pipeline walls' condition. Carried further on analysis of magnetic field distribution with the help of special methods provides the selection of defects depending on their type, surface orientation and estimate the sizes (depth and elongation).
The defectoscopes of KOD-4M type provide the detection of defects as longitudinal cracks with the depth of 10% and more of wall thickness and with the minimal extend of three wall thickness. A family of neighboring cracks is detected with the simultaneous estimation of common extend of defect area and the depth of maximal crack in the family.The defectoscopes of KOD-4M type provide the detection of wall corrosion damage as well.The defectoscopes of KOD-4M type may be used for gaspipelines with diameters from 720 mm up to 1420 mm inspection and they have different design of interact with pipeline systems.
So, if the equipment is used for inspection of thick wall pipelines (the wall thickness up to 26 mm) then the special magnetization system is used.
The intelligent pig KOD-4M-1420 passed trial in main's gas pipeline subjected to stresscorrosion cracking.
Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00
Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:
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