Magnetic flux leakage inspection systems

Magnetic flux leakage (MFL) inspection sends a magnetised tool through a pipeline: where the wall has lost metal to corrosion or damage, flux leaks out of the steel and sensors map the defect's position and size. This line covers the hardware and the service around it. The pipeline inline inspection tools are the core MFL pigs, covering pipe diameters from 159 to 1,422 mm with more than 20 tool specifications. The illegal tapping detection machine applies the same technology to locating unauthorised offtakes, the eddy current testing machine covers small-bore lines down to DN65 with a complementary method, and the MFL inline inspection service delivers the full survey as a service for 8–56 inch lines.

Operating envelope on record

The tool pages publish a consistent envelope: 0–10 MPa pressure range, -10 to 80 degrees C working temperature, bend passage at a radius of 1.5D or greater, and continuous running times of 50–60+ hours depending on model. Defect positioning is recorded against the nearest circumferential weld (+/-0.1 m) and circumferential direction (+/-5 degrees).

Choosing a method

MFL and eddy current answer different questions: MFL quantifies wall loss through the full wall thickness on larger lines, while eddy current suits small diameters and near-surface defects. Our MFL vs eddy current comparison and the MFL testing guide explain both before you commit a line to a survey window. New to the method? Start with the pipeline inspection guide.