Tube end and mandrel breakage detection play an important role in the manufacture of seamless tubes. For control and monitoring of incidents in production plants, eddy current testing systems can also serve as sensors in addition to fault checking.

Tube end detection

In the manufacture of seamless tubes, the tube ends are led to a steel mandrel bar on the rolling unit. The motion is not continuous but gradually sliding and turning. The coupling joint between the tube ends must be detected in order to control the process sequence. An eddy current tester with a suitable probe provides this information very precisely.

Mandrel breakage detection

The rolling mandrel that is driven into the tube bore can break off during production and get caught in the finished tube. This mandrel breakage can be detected with the aid of an encircling coil, and the machine can be stopped.

The loop end and mandrel breakage detection is performed with the following FOERSTER test electronics:

DEFECTOMAT: The DEFECTOMAT testing system checks the tube surface for point and transverse defects using the eddy current method. The system – equipped with the appropriate sensors – can also be used to detect tube end and mandrel breakage.