TPT September 2008

or manual tracking. The coils are adjusted according to the weld seam in a horizontal plane. The second basic design is for seam annealing with orbital tracking. With this system, the coil will follow a twist in the seam, keeping a constant distance between the induction coil and the weld seam. Orbital tracking is most common for large OD pipes. The system can be supplied with fully automatic tracking or manual tracking.

EFD Induction has designed three basic types of systems that will optimise these parameters. A special coil development has been performed over some years with improved results for temperature homogeneity through the wall. This design is now in use for seam annealing of pipes with heavier walls. The first basic design is for seam annealing with horizontal tracking, a system that can be supplied with fully automatic tracking

capabilities along with the Windows XP ‘Embedded’ operating system, which makes the system virtually hack-proof. Coupled with Eddytrend digital recording software, the Eddychek 5 becomes a powerful data collection and archiving system. Using new data compression algorithms, 100 per cent of the amplitude and vector component signals from each tube are retained. Signals may then be played back in real time for later analysis. In addition, they can be printed in document form or emailed as HTML. Website : www.eddytech.com  The Eddychek-5 Advanced includes a colour touch-screen display EFD Induction, Norway, is a supplier of seam annealing equipment for the normalising process (N), normalising, quenching and tempering process (NQT), and normalising, quenching and normalising process (NQN). In the production of welded pipes according to API, ISO and other standards, a normalisation of the weld and heat affected zone (HAZ) is required. The aim for the heat treatment is to re-establish a homogeneous and fine-grained microstructure in the HAZ. To achieve a fine-grained microstructure after the normalisation, it is important to limit the temperature on the external surface of the pipe, which is closest to the coil, to avoid grain re-growth and to reach high enough austenitisation temperature in a sufficiently wide zone at the inner surface. The width at the inner surface must cover the width of the HAZ, which has its maximums at the surfaces. EFD Induction Norway 8225

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S eptember 2008

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