TPT September 2008

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105 September 2008 ›
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:
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 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
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.
 The Eddychek-5 Advanced includes a colour
touch-screen display
EFD Induction
Norway 8225
