On-site demagnetization - demagnetizes pipelines for example

Goudsmit recently demagnetized PE-coated pipes delivered for the construction of an oil refinery in Southeast India. This operation was essential because the residual magnetism present in the pipes prevented welding, thus halting the construction of the refinery. To eliminate this residual magnetism or reduce it to a compatible level, the company developed a system consisting of a low-frequency generator and a specific wiring system. The working method is as follows: the cable is wound in a coil around the pipes. A powerful alternating magnetic field is then generated within them and gradually brought to zero. The residual magnetism is thus eliminated or reduced to a remarkably low value of approx. 35 Gauss. In this case, it involved about 40 carbon steel pipes, each 12 meters long and with a diameter of ø 470 mm.