Study on the Influence of Coil Placement on Pulsed Eddy Current Testing

Abstract

The pipeline system of plant is installed with an insulation layer on the outer wall of the pipeline. Currently, the primary methods of detecting pipeline system is ultrasound and uradiographic testing, which require the removal of the outside layer before testing. As a result, detecting time extends, and labor costs increase, increase the risk of accidental exposure. Applying the PEC technique for steam pipelines can eliminate the disassembly of insulation and achieve non-stop online screening. The defects testing by coil placement is an essential indicator of the PEC technique, which is the main influence factor of PEC accuracy. The article intensifies the modeling and simulation of the pipelines by applying Ansys Maxwell and designs coaxial and vertical detection coils to simulate the detection capability of PEC on flat bottom defects in case of consistency in the lift-off distance, materials, and other conditions. It selects nuclear power plant sample pipes for coaxial and vertical PEC testing. Recording the test result of PEC and UT methods, and the effects of two coil placement methods on PECT are compared. Finally, the study proposes development trends.