Automatic Pipe-end Flaw NDT Method and Equipment based on PMP Sensor Array

A new automatic NDT method based on permanent magnetic perturbation(PMP)sensor array is proposed for pipe end flaw inspection. The relative motion between the detecting sensor and the pipe is analyzed, and then the solution is determined to assure the consistency of longitudinal and transverse flaw detections. The method is verified through relevant experimental apparatus. A PMP sensor array for automatically tracing pipe end jigging is designed, based on which a new automatic NDT system for pipe end flaw inspection is developed, and technological requirements for the inspection process are also defined. Thanks to the said new NDT method, the undetected area of the pipe end shall be considerably reduced. Moreover pipe inner and outer surface flaws can be detected separately owing to such a design that the sensors for inner surface detection and those for outer surface are independent to each other, which allows for identifying inner surface flaws from outer surface ones.