TPT September 2016

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66 September 2016
T E CHNOLOG Y
Purging large diameter pipes for welding
WAITING for pipes to be purged ready
for welding can take hours, depending
on the diameter of the pipe being welded
and the method chosen for purging.
Huntingdon Fusion Techniques (HFT)
designs and manufactures a range of
QuickPurge® inflatable pipe purging
systems that reduce waiting times. The
company was recently tasked with a
special project in the USA, where pipes
with 90° elbows, up to 54" Ø, were
required to be purged.
Georgia Gascoyne, CEO at HFT,
said, “We manufactured QuickPurge
systems with longer sleeves so that they
could easily be pulled around the sharp
bends in the pipework. The welders
were previously spending half a day
purging the pipe, which was costing a
considerable amount in time and gas
costs. With the help of QuickPurge
the pipe was purged down to 100 ppm
ready for welding in just 55 minutes. The
dramatic savings in time and argon paid
for the system in just one weld.”
QuickPurge has an additional gas
input line, which means extra purge gas
can be introduced for applications such
as this, achieving a faster purge down
to the lowest oxygen levels, which is
suitable for larger diameter pipes where
quality welds are required.
The design of the QuickPurge
system means that zero-colour welds
can be achieved, and there will be no
loss of corrosion resistance caused by
oxidation.
Using IntaCal® combined with the
integrated PurgeGate® device makes
it possible to safely inflate the dams
with argon gas, for purging the space
between the dams where the weld joint
is located.
With PurgeGate, burst dams are
prevented in the event of undue pressure
increase or accidental flow increase of
the purging gas.
All systems are manufactured as
standard with a hose for connecting a
Weld Purge Monitor®, which can read
oxygen levels down to as low as 10
ppm, depending on the model.
Materials used in the manufacture
of QuickPurge are resistant to the
higher weld temperatures present, and
they do not outgas, preventing weld
contamination.
For pre-heated chrome steel and
high strength stainless steel pipe joints,
HFT designs and manufactures the
HotPurge™ range for a higher and
longer temperature exposure.
Huntingdon Fusion Techniques – UK
Email:
Website: HFT’s QuickPurge systems