Electromagnetic Coupling Sensing of Pipe In-Line Inspection System.

In-line inspection (ILI) technology is a crucial tool for maintaining pipeline integrity. However, it faces considerable challenges such as adaptability in identifying various types of faults. In this article, a new type of ILI system based on electromagnetic induction and magnetization is proposed. First, a novel magnetic ring structure (MRS) is developed which can generate axial magnetic flux leakage and a circumferential uniform alternating current field. Second, the magnet structure's configuration is modified and extended so that the pipe wall's penetrating ability and magnetic flux are strengthened. This improves the detection capability for shallow surface defects as well as deeper hidden faults while ensuring trafficability and overcoming the detection performance constraint of single detection technology. To evaluate the feasibility of the proposed MRS system, an actual pulling test was performed. The proposed method's detection rate and penetration capabilities are verified by finite-element modeling and experiments.