According to the requirements of API standard require the detection of surface defects on the steel pipe in the pipe end portion of less than 200mm. The device uses the ends of the steel pipe was seized composite magnetization, and then infrared light irradiation spraying in magnetized steel pipe surface magnetic fluid, artificial naked eye defect crack, to find the inner and outer surface defects.
The steel pipe, the so-called composite magnetization is the system of the two directions of magnetization the closed yoke of longitudinal magnetization of one-way full-wave DC. AC circumferential magnetization, the longitudinal magnetization with DC, so you can composite magnetization. A composite magnetization of the machine, can be found the tube end magnetization within the outer surface of the defect in each direction.
Steel pipe was seized after degaussing machine degaussing non-magnetic state can be restored through the inspection process.