On-Line Flux Leakage Weld Testing For ERW Tube & Pipe
InspecTech® A Division of InspecTech Analygas Group Inc. 450 Midwest Road, Toronto, Ontario, Canada, M1P 3A9 Tel: 416-757-1179 Fax: 416-757-8096 Email: firstname.lastname@example.org Web: www.inspectech.ca
Inspect small diameter tubes, on-line, at high speeds.
Superior Absolute and Differential operation compared to Eddy Current inspection systems.
Ideal NDT for carbon steel tubes, ø12mm and up in diameter.
Capable of testing Galvanized and Aluminized product.
Calibrates to 10% OD & ID notches, and 0.8mm holes.
Flux Leakage testing is economical and user-friendly
The complete Flux Leakage NDT test system includes two basic components: the robust
mechanical subsystem that manipulates the on-line sensor, and the electronic package,
which processes the signals from the sensor.
InspecTech® offers two standardized Flux Leakage weld test units, based upon the
size of product to be tested. Systems can be custom built for other size ranges or
The smaller unit magnetizes the tube from below and is suitable for products in the
general range of diameters from 0.5” (13mm) to about 3.5” (90mm).
The larger system is an overhead version, which magnetizes from above and is used
for diameters 2” (50mm) and up.
Test heads cover a wide test zone allowing for weld wander.
Flux Leakage testing relies on magnetic field measurement close to the surface of
magnetized material. Flaws (defects) in the material cause “leakage” of the magnetic
With the absolute and differential channels, this Flux Leakage system is able to
detect a wide variety of defect types, from ID and OD notches to pinholes and also
some types of cold and pasty welds.
The InspecTech Flux Leakage software has a Data Logger, designed to log all the significant
events that occur during the test session such as alarms, flaws detected, calibration
data and system events throughout a shift. Stored data can be later hard-copied or
downloaded. Strip Charts can also be retrieved at a later date.
The preferred location of the flux leakage test system within the mill process stream
should be immediately downstream of the weld process. Often, this is not always practical
due to plant layout and sometimes there may be reluctance to locate the test station
in this particular area of the production line.
The closer the test station is located after welding, the more rapid will be the
feedback of defect information and the subsequent correction of the problem.
Cooling of the tube (momentarily) is IMPERATIVE for sensor operation as temperatures
in excess of approximately 100° C can affect the devices utilized in the sensor assembly
Testing close to the weld station will lessen the possibility of losing signal due
to the tendency of the product weld line to drift from centre.
The Flux Leakage method of testing tubular goods has been used for many decades for
full body inspection. Using this method to test weld seams in small diameter (12mm
and up) tubes has, up to now, not been practical because of the difficulties in obtaining
uniform magnetic fields with minimal pole piece spacing.
InspecTech® has refined the Flux Leakage method, using advanced signal processing.
InspecTech remains the only test equipment manufacturer to offer Flux Leakage weld
testing equipment for tube producers, to be used directly on the tube mill.