Magnetic non-destructive testing methods can be classified into the earliest methods developed for assessment of steel constructions. One of them is the magnetic flux leakage technology. A measurement of the magnetic flux leakage is quite commonly used for examination of large objects such as tanks and pipelines. Construction of a magnetic flux leakage tool is relatively simple, but a quantitative analysis of recorded data is a difficult task. Therefore, methods of magnetic flux leakage signal processing and analysis are still under development. A magnetic flux leakage in-line-inspection tool called FLUMAG 500 was constructed. FLUMAG 500 was designed for gas and oil pipelines inspection. In this paper principle of operation of FLUMAG 500 was described. Advanced algorithms of the signal processing and analysis was also developed. Results coming from the development stage as well as from the final construction of the tool were presented. Analysis of these results shows that FLUMAG 500 is a suitable tool for detection of corrosion defects in a pipeline wall.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Ahmad, Z., Principles of corrosion engineering and corrosion control. Butterworth-Heinemann, 2006.
2. Porter P.C., Use of magnetic flux leakage (MFL) for the inspection of pipelines and storage tanks. Proc. SPIE 2454, Nondestructive Evaluation of Aging Utilities (1995), 172–184.
3. Bubenik T.A., Nestleroth J.B., Eiber R.J., and Saffell B.F., Magnetic flux leakage (MFL) technology for natural gas pipeline inspection. Topical report, November 1992.
4. Sutherland J. and Paz H., Advances in in-line inspection technology for pipeline integrity. 5th Annual International Pipeline Congress, Morelia, Mexico, 2000.
5. Park G.S., Park S.H., Analysis of the velocity-induced eddy current in MFL type NDT. IEEE Trans. Magn. 40 (2004), 663–666.
6. Afzal M., Udpa S., Advanced signal processing of magnetic flux leakage data obtained from seamless gas pipeline. NDT&E Int. 35 (2002), 449-457.
7. Piotrowski L., Chmielewski M., Analysis of the magnetic flux leakage signal detected by a pipeline inspection gauge with the help of the continuous wavelet transform. Journal of Electrical Engineering 66 (2015), 182-185.
8. Carvalho A.A., Rebello J.M.A., Sagrilo L.V.S., Camerini C.S., and Miranda I.V.J., MFL signals and artificial neural networks applied to detection and classification of pipe weld defects. NDT&E Int. 36 (2006), 661-667.
9. Usarek Z., Influence of sample geometry, magnetic properties and a method of magnetisation on the spatial distribution of the stray magnetic field.. PhD dissertation (in Polish), Gdańsk University of Technology, 2017.
10. Mandayam S., Udpa L., Udpa S.S., and Lord W., Signal processing for in-line inspection of gas transmission pipelines. Res. Nondestruct. Eval. 8 (1996), 233–247.
11. Lei L., Wang C., Ji F., and Wang Q., RBF-based compensation of velocity effects on MFL signals. Insight 51 (2009), 508–511.
12. Lu S., Feng J., Li F., and Liu J., Precise Inversion for the Reconstruction of Arbitrary Defect Profiles Considering Velocity Effect in Magnetic Flux Leakage Testing. IEEE Trans. Magn. 53 (2017), 1–12.
13. Manual for Determining the Remaining Strength of Corroded Pipelines, Supplement to ASME B31 Code for Pressure Piping. An American National Standard – ASME B31G-2012.