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Issue Three of Weld Purging World - July 2019

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Published by marketing, 2019-07-15 10:17:01

Weld Purging World - July 2019

Issue Three of Weld Purging World - July 2019

ISSUE 3: July 2019

In July’s Issue:

• Focus on Distributor: The Netherlands
• 2019 Calendar of Exhibitions and Events
• HFT® News: Visiting Cranfield University,

Ireland and South East Asia
• Product News: PurgEye® Site, Low Profile

Stoppers and QuickPurge®
• Technical Article: Welding New Nickel Alloy


Huntingdon Fusion Techniques HFT® are proud members of:



Weld of the Month and Distributor Feature 3
HFT® News 4
Industry News 5
HFT / Product News 6-7
Technical Paper 8-9


Dear Reader,

Welcome to July’s Weld Purging World.

It’s been a very exciting few months here at HFT®. With
some new products in development, a new demonstration
room at our UK HQ about to be unveiled and preparation
work beginning for the big Industry Shows Fabtech and
Adipec in November.

In this issue read about our recent visits to Cranfield
University, Ireland and South East Asia.

Also, find out where we will be Exhibiting this year!

If you have any news or would like to be featured in our
magazine, then please get in touch.

Thank you for reading!

Best wishes,

Marketing and Social Media Manager
[email protected]


Weld of the Month goes to one of our Instagram Followers,
Brad Bingham (@binghambuilt). Head over to his page to see
more of his work.

If you are using our products and would like to enter to have
your weld featured as Weld of the Month, tag us in your weld
photos. We will try and repost them on our Instagram page too.
Extra points if you can get our product in the photo too...


Pipeq Pipework Equipment
HFT® Distributor for The Netherlands,
Belgium and Luxembourg

Pipeq Pipework Equipment have been
successfully distributing HFT® products since
2013. Offering enormous know-how in the field
of weld purging and pipe preparation, Pipeq’s
suppliers are all renowned manufacturers,
each with their own expertise.
As an importer, Pipeq Pipework Equipment supplies to welding technical wholesalers and companies
in the Netherlands and Belgium that manufacture and maintain pipeline systems, pipework or process
equipment. Their customers include companies in the process industry, oil and gas, offshore, bio
and petrochemicals, pharmaceutical, food industries and the environmental and energy industries.

Pipeq Pipework Equipment focuses not only on sales, rental
and service, but also on training and advice.
Rob van der Heijden, Managing Director for Pipeq said: “With a
clear focus and expertise on weld purging and pipe preparation,
we offer the best advice and service to our many customers.
Pipe fitters and welders opt for quality, reliability and service
Pipeq Pipework Equipment maintains excellent communication
with a select number of leading manufacturers on the one hand
and its customers on the other. To maintain a lead in the field of
(pre) fabrication of pipeline systems and heat exchangers, our
customers consciously opt for these reliable and reputable OEMs.
Together with these brands that we exclusively represent in the
Benelux, we offer clear and professional advice and professional
service. Our partners deliver, each with their own specialism,
years of expertise and first-class products.”

If any of our Distributors would like to feature here, then please get in touch!



Located in Bedfordshire, UK, Cranfield University
is a postgraduate and research-based public
university specialising in science, engineering,
technology and management, founded as the
College of Aeronautics in 1946.
Our CEO Georgia made a visit to the University
recently and said: “HFT® has been working closely
with Cranfield University for many years now.”
“We have supplied many Special Welding
Enclosures, which provide total inert gas coverage
when welding titanium parts along with other
reactive metals.”
“They have a department for welding in the Additive
Manufacturing Industry and pictured is a special
3m cube Enclosure with a complete robot inside.”


HFT®’s Technical Sales Manager Luke travelled over
to our Exclusive Distributor in Ireland, Metron Welding
to provide support with their recent in house event.

Metron Welding arranged 24’’ stainless and carbon steel pipelines to
showcase the products they have available for pipe fabrication to the
key companies within Ireland.
Luke demonstrated the speed and reliability of the QuickPurge®
System, showing just how quickly the oxygen could be purged, down
to as low as 10 ppm.
All who took part in the event agreed that it was a great success,
with both the quality of the equipment on display and the blue chip
companies that attended.



Luke also recently visited our Distributors and Customers in
South East Asia.
Luke Said: “Leeden Nox in Singapore was the first stop on my
Journey, where I was able to carry out some up to date product
training, before making my way to Malaysia and then on to
“We have been able to provide cost saving solutions for a variety
of purging applications to key customers within this region.”

“The majority of material was duplex, requiring a low
oxygen content of 15-20ppm.”

“Using the HFT® purging systems on a multitude
of pipe diameters, we achieved these levels in
minutes, demonstrating just how much inert gas,
time and money can be saved with the right purging


25 - 27 July 3 - 6 September
Oil and Gas Africa SPE Offshore
Nairobi, Kenya Aberdeen, UK

16 – 21 September 18– 20 September
EMO Hannover
Hannover, Germany tube

Exhibiting! Bangkok, Thailand
11 - 14 November
Fabtech Exhibiting!
McCormick Place, Chicago, IL, USA 11 - 14 November
Adnec, Abu Dhabi

26 - 28th November Distributor Exhibiting!
Stainless Steel World 27 - 28 November
MECC Maastricht, The Netherlands MetalMadrid
Ifema, Madrid, Spain


1. Weld Purge Monitor for On-Site Conditions


Welding on site can pose difficult challenges, including
exposure to extremes of heat and cold, harmful sand and dust
and even hazardous fumes. Contamination during welding
can lead to loss of corrosion resistance and a reduction in
strength so control of oxygen levels is crucial.

With another innovative development, Huntingdon Fusion
Techniques HFT® have designed a virtually non-destructible
Weld Purge Monitor® to work accurately within extreme
environments. The PurgEye® Site is an oxygen monitor in a
secure, safe, waterproof and dustproof, tough carry case.

Technical Sales Manager Luke Keane said: “The PurgEye® Site has been specifically designed for
extreme conditions. By using this monitor, welders can ensure non-oxidised, zero colour welds.”

“With the housing case open, the PurgEye® Site is IP65 rated and IP68 rated with the lid closed.
The PurgEye® Site measures oxygen levels very accurately from 1,000 ppm, right down to 10 ppm.”


Pipe blocking, plugging and sealing for duties such as repair
work, leak testing, weld purging and debris stopping is easy
with Pipestoppers®.

The Pipestoppers® Division at Huntingdon Fusion
Techniques HFT® design and manufacture a Range of
Mechanical and Inflatable Pipestoppers® and Plugs to suit a
variety of applications.

The Low Profile Stopper is available for applications where insufficient length of pipe is available for
the regular Cylindrical or Spherical Inflatable Stopper.

Ron Sewell, Chairman at HFT® said: “The Low Profile Stopper can fit into a pipe end that may be
directly on an elbow or just inside a flanged neck on a casting. Other applications include blocking
pipe ends to keep gases inside or to keep debris and vermin out.”

Manufactured from tough, robust fabric, these Low Profile Inflatable Stoppers are available in sizes
6 to 88” (150 to 2,235 mm) and provide excellent grip inside the pipe, with an effective airtight seal.

Each Low Profile Stopper is fitted with a standard Schrader Valve connected to a 1.2m hose, is easy
to inflate using a foot pump or compressor and is heat resistant up to 90ºC (194ºF).



Purging large diameter pipework ready for welding can be expensive. Without restricting the volume,
there is a high cost involved in inert gas used and time spent waiting for the oxygen level to reach a
level low enough for welding to begin.

Weld Purging experts Huntingdon Fusion Techniques HFT® have
designed and developed QuickPurge® Systems to dramatically
reduce the space that needs to be purged, for pipes as large as 88”
(2,235 mm).

HFT® was recently tasked with a special project in the USA, where
pipes with 90o elbows, up to 54” (1,371 mm) ø were required to be

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, thereby achieving a much faster purge, down to the lowest oxygen levels,
which is perfect for larger diameter pipes where quality welds are required.

High speed pipe purging system QuickPurge® is leading the way in the field of purging tube, pipe
and pipeline joints over 6” diameter, where oxygen levels are required to be as low as 100 parts per
million (ppm) or less.

Huntingdon Fusion Techniques, HFT®’’s innovative design of the QuickPurge® System means that
zero colour welds will be achieved and there will be no loss of corrosion resistance caused by

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® to,
which can read oxygen levels down to as low as 10 ppm depending on the model.

Materials used in the manufacture of QuickPurge® are such that they are resistant to the higher
weld temperatures present and they don’t outgas, preventing weld contamination.


New superalloys still need careful purging during welding.
Significant developments have been made recently and have resulted in the introduction of new
nickel alloys that offer major improvements in mechanical properties.
Not least is Inconel 740H (Ref 1), an alloy offering enhanced resistance to coal ash and therefore of
considerable interest to fossil fuel fired boiler manufacturers.
Whilst these new materials help to expand the use of nickel-based alloys in areas where mechanical
properties and corrosion resistance at elevated temperatures are mandatory, the need to maintain
strict control during fusion welding remains, in order to preserve these characteristics.
Inconel 740H has a higher chromium content than other alloys in this class of materials and as
a consequence offers significant high temperature corrosion resistance. Notwithstanding this
characteristic all the alloys, and particularly Inconel 740H, are prone to loss of chromium through
oxidation (Ref 2) during welding unless some form of protection is provided (Ref 3).
With respect to Pipework and Boilers failure to purge, or failure to purge properly will result in a heavily
oxidised surface to the weld root inside the cavity with substantially lower corrosion resistance. Even
after the completion of the root weld, the weld purge should be continued for several passes to avoid
Heat Tint, or discolouration (oxidation) inside the tube or pipe.
When using the GTAW process direct protection of the upper weld deposit can be assured through
the inert gas shroud and the use of a Trailing Shield. The weld root however is fully exposed to the
atmosphere and oxidation can take place.
An essential requirement when making butt joints therefore is to provide interior inert gas purging
typically with argon or helium (Ref 4).
With very small tubes this can usually be achieved through careful continuous gas flow but this
technique is prone to erratic coverage because of turbulence. Isolating the section to be welded
by inserting dams on either side of the joint and filling the volume with inert gas is a much better
Attempts have been made to provide dams using paper, card, timber or even polystyrene plugs
on the basis of economy but success is erratic – sealing is difficult, contamination is inevitable and
effective removal of the debris following welding is difficult.
The best solution, and the one now adopted globally by leading fabricators, is to employ commercially
available integrated inflatable purging systems (Figs 1 - 3).

Figure 1. Operation of inflatable purge system for high temperature pipe welding with heat resistant material, hoses
and fittings.


For adequate protection of nickel alloys during welding the internal purge atmosphere should have
oxygen level reduced to 50 ppm (0.005%) or less in order to obtain a root surface with little or no

Figure 2.
These examples from the QuickPurge® range are representative of proven purge systems.

They cover the entire pipe size range between 152 and 2235 mm diameter.

Control of purge gas oxygen content during welding is clearly an important aspect. Recent
development in monitoring instruments (Fig 3) have led to the introduction of equipment that not
only measures oxygen level accurately but also provides facilities for continuous recording and even
overrides the joining process if oxygen levels exceed those pre-set by the operator.
Techniques for measuring oxygen content have been available for decades but only recently have
instruments been developed specifically for welding applications. Users increasingly demand
complete absence from discolouration and no loss of corrosion resistance and this implies purge
gas oxygen content to be as low as 20 ppm (0.002%). Very few oxygen purge monitors are capable
of meeting this sensitivity, but the PurgEye® [Figure 3] instruments cover all requirements.

Figure 3.
PurgEye monitors include full colour touch screen control.
The instruments support data logging and weld certification. Readings are accurate down to 10 ppm (0.0001%).
Characterization of INCONEL alloy 740H for Tube, Pipe and Fittings for Advanced Supercritical CO2 Systems. de
Barbadillo et al. 6th International Supercritical CO2 Power Cycles Symposium, March 2018, Pittsburgh.
Oxidation of nickel and cobalt based superalloys. Defense Metals Information Center. Battelle Memorial Institute
Columbus, Ohio. Report 214 March 1, 1965.
Welding of nickel alloys - Part 1 - Job Knowledge 107 – The Welding Institute, Cambridge UK.
Inert gas weld purging of pipes. M J Fletcher. Engineer Live, May 2017.
Fig 1-3: Reproduced courtesy of Huntingdon Fusion Techniques Ltd, UK

By Michael Fletcher, PhD Metallurgy, Leeds University.


Inflatable Tube and Pipe
Weld Purging System

Available in sizes 1 to 24 inch
(25 to 610 mm) diameters



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