Magnetic-thermal gradient difference test technology for non-excavation heating pipelines

Proposes a method of magnetic-thermal gradient difference test for the heating pipeline leakage test. Presents the test principle of the method. Through the finite element analysis of the heating pipeline, verifies the feasibility of the method from the principle. Invents a kind of magnetic-thermal comprehensive test instrument for non-excavation heating pipeline, and verifies its reliability in a practical project. The results show that it can locate pipeline leak quickly and accurately, with the leak test rate of over 90%.