Demagnetization of Pipelines on Field

High-pressure gas pipelines must meet the highest safety standards and operating companies, in order to comply with their integrity, resort to the use of intelligent inspection tools such as SMART PIGS, one of the most recurrent technologies is the “Magnetic Flux Leakage” (MFL) pigs to verify the thickness of the pipe walls. For this purpose, the Diablos have rings of very strong magnets that generate induced magnetic flux lines that are recorded by sensors.
Problem: the inspected lines are permanently magnetized (residual magnetism), then when the reports of the pig’s run are received, many times some repair has to be done as soon as possible.
The magnetization of the pipe at the time of repairs causes the welding arc to be deflected, causing the appearance of pores and joint defects in the welding seams, to avoid this, PETROPIPE has the demagnetization service through trained technicians and a device that measures the intensity of magnetization (GAUSSMETER) and another device can lead to values of “zero”, for this creating a counter-magnetic field (DEGAUSS 600) of equal strength, eliminating the residual magnetism, to achieve a perfect weld.