Magnetic flux leakage (MFL) is a fast inspection technique, suitable for measuring wall loss and detecting sharp defects such as pitting, grooving, and circumferential cracks. MFL is effective for aluminum-finned carbon steel tubes, because the magnetic field is almost completely unaffected by the presence of such fins. MFL tube shall be use on tubular products having outside diameters from approximately 1⁄2 to 24 in. (12.7 to 610 mm) with wall thicknesses to 1⁄2 in (12.7 mm) and below. MFL- tube testing can be used for following applications.