Weld Purging World - May 2020

ISSUE 05: MAY 2020

IN THIS ISSUE:

INTRODUCING OUR NEW DESIGN

WELD TRAILING SHIELDS®

PIPE PURGING MASTERS WEBSITE
WELDING TITANIUM THE FUTURE FOR WAAM

WELD PURGING PRODUCTS
INNOVATORS, MANUFACTURERS AND
INTERNATIONALLY RENOWNED SPECIALISTS
MADE IN WALES ‘MANUFACTURER OF THE YEAR’ &
WELSH BUSINESS AWARDS – EXPORTER OF THE YEAR

WWW.HUNTINGDONFUSION.COM

2 CONTENT

WHAT’S IN THIS MONTH’S ISSUE

Product Update: Weld Trailing Shield 3

HFT® News 4-6

Product News 7-8
9 - 13
Technical Paper: The Future for
WAAM

A WELCOME FROM THE EDITOR

Dear Reader,

Welcome to the May Issue of Weld Purging World.

In this month’s issue, we are delighted to give you the first official look at our new style Argweld®
Weld Trailing Shields®. The addition of a Trailing Shield when welding stainless steel and titanium
will ensure your weld remains under an additional inert gas coverage while it cools, preventing
the hot metal from coming into contact with air and oxidising. Be sure to turn over to take a look
at our new sleek design!

We also give details on our new Pipe Purging Masters
Website and our Technical Paper, The Future for WAAM is
featured on page 9.

If you have any information that you would like to be
featured in this publication, please contact me. Perhaps a
photograph of a special weld that you have made, a product
that you find of interest or a question of some kind?

From everyone here at HFT®, thank you for reading and
stay safe!

Best wishes,
Michaela

Marketing and Social Media Manager
[email protected]

HFT® NEWS 3

PRODUCT UPDATE: WELD TRAILING SHIELDS®

They’re here! Our NEW style Argweld® Weld Trailing Shield® will be launched this week!
What has changed on the new design?
Along with the new sleek design, our Trailing
Shields® have a NEW Unique clip design,
which means the welder can interchange
different trailing shield sizes without having
to change the welding torch.
With our name and logo stamped onto every
new Trailing Shield, you can be sure the
Shield you are using is a HFT design, we
guarantee quality and 100% craftsmanship.
Why should I use a Trailing Shield?
Inert gas is probably the highest cost
consumable in welding, second only to
the cost of filler wire. More important then,
that control is exercised when inert gas is used in weld purging. The most efficient purge systems
minimise the use of inert gas. HFT® Trailing Shield® design is such that gas used is carefully
controlled. There is virtually no loss due to leakage and turbulence.

Argweld® Trailing Shields® are designed for high quality
gas coverage of titanium, zirconium and stainless steels
during welding to prevent oxidation and weld defects. They
will fit any make of TIG (GTAW) or plasma (PAW) welding
torch for welding flat sheet or plate and the OD or ID of tubes
or pipes. For pipes and vessels the radiused versions are
manufactured to suit diameters from 25 mm and upwards.
By using an Argweld® Trailing Shield® welds will be left
bright and shiny and eliminate discolouration and oxidation.
The silicone (side skirt) gasket is resistant to temperatures
up to 230ºC.
Argweld® Trailing Shields® will reduce gas consumption,
save re-work and eliminate wasted material costs due to
oxidation and weld defects. Argweld® Trailing Shields® can
be used for welding stainless steels, duplexes, titanium and
zirconium and any other weld able metal where discolouration
or oxidation needs to be eliminated.
User Quotes:
“Easier to use than you would think”.
“The best advantage is that it keeps the weld torch 90º to the
weld pool”.

4 HFT® NEWS

MANUFACTURED WITH QUALITY

Here at Huntingdon Fusion Techniques HFT®, we manufacture all of our Weld Purging Systems and
Weld Purge Monitors® with consistent quality of materials and guaranteed craftsmanship.

Awarded ‘Manufacturer of the Year Award 2019’ at
the Made In Wales Awards was a true recognition of a
company being committed to Quality Manufacturing.
Weld Purge Monitors®
Our PurgEye® Weld Purge Monitors® have been
designed and manufactured with scientific knowledge,
specifically for welding, providing accurate readings right
down to 10 ppm we have a Weld Purge Monitor® to suit
every application and budget.

Argweld® PurgElite, QuickPurge, HotPurge, Single
Purge Dams
Drastically restricting the volume required to be purged, the
use of our Inflatable Pipe Purging Systems will save welders
time and inert gas costs, whilst achieving high quality each
and every time.
Heat Protective Covers for PurgElite and Inflatable
Stoppers
Manufactured from a robust material, the Heat Resistant
Covers protect the inflatable dams at each end of the
system, with a temperature range of up to 300ºC (572ºF).
Weld Trailing Shields®
Designed for high quality gas coverage of titanium and stainless steel during welding to prevent
oxidation, Weld Trailing Shields® will fit any make of TIG (GTAW) or Plasma (PAW) welding torch
for manual or automatic welding, on flat sheet or plate and the outsides or insides of tubes or pipes.
Argweld® Flexible Welding Enclosures®
Flexible Welding Enclosures® have been designed for applications where a rigid chamber may
not be economically viable or where space may be at a premium. They are low cost and suitable

for welding titanium, zirconium and other reactive metals. The
enclosures are also widely used for WAAM Additive Manufacturing
and for manufacture of smaller components where total inert gas
protection is required
Techweld® Tungsten Electrode Grinder
Ensuring your Tungsten Electrode is sharpened correctly using
the TEG-1000 is a more convenient, safer and accurate way than
other methods of grinding Tungsten Electrodes.
Pipestoppers® Steel, Aluminium and PlugFast Pipe Plugs
Inflatable Stoppers, PetroChem Stoppers and Low Profile Stoppers
These versatile Inflatable Stoppers are used to service a wide diversity of industrial applications,
for pipes and ducts as a quick and easy way to stop the flow of gas or liquid, to stop the build up of
debris and to prevent ingress of unwanted material or animals.

HFT® NEWS 5

WELDING TITANIUM

Weld Purging of titanium joints. As titanium is a reactive metal, correct weld purging is possibly
more critical than with most other metals.
There are some major elements whilst welding titanium, to ensure successful welds are achieved:
A good source of weld purge gas.
Welding gas suppliers all have special high quality grades of argon, which is the most widely
recommended gas for back purging titanium. Typical grades are 99.9995% which is 5 parts per
million of impurities.
A Weld Purge Monitor® to measure the oxygen
level in the weld purge gas as it exits the purged
volume.
Part of the correct weld purging procedure is to ensure
that the oxygen level in the exiting weld purge gas is
held at 40 parts per million or lower and maintained
throughout the weld. This is best achieved by using
a Weld Purge Monitor® that can measure down to 10
parts per million and one that preferably can switch the
weld set off or send out a warning signal in the event of
oxygen levels rising too high.
For titanium tube and pipes, an Inflatable Tube and Pipe Purging System.

Restricting the volume required for purging with an Inflatable
Tube and Pipe Purging System will help dramatically reduce
costs. PurgElite® and QuickPurge® will help achieve zero
colour welds with no loss of corrosion resistance properties.
For titanium parts, a Flexible Welding Enclosure.
Reliable exclusion of reactive gases in the welding
environment is guaranteed when using a low cost Flexible
Welding Enclosure®. Special Flexible Welding Enclosures®
can be designed and manufactured to suit any purpose.
The Welding Enclosures are ideal for small production
quantities of items that need total gas coverage as well as single large items with critical joints.

1.

CALENDAR: EVENTS IN THE INDUSTRY


TechniShow TWI’s Welding & Joining

1 - 4 September 2020 7 - 10 October 2020

Utrecht, Netherlands Cambridge, UK


Adipec Fabtech Tube

9 - 12 November 2020 18 - 20 November 2020 7 - 11 December 2020

Abu Dhabi, UAE Las Vegas, USA Düsseldorf, Germany

6 HFT® NEWS

1. Weld Purge Monitor for On-Site Conditions

PIPE PURGING MASTERS

We’ve recently launched a small, easy to navigate website called Pipe Purging Masters. At www.
pipepurgingmasters.com, you will find all of our latest product information, recent Blogs and contact
details.
Tube and Pipe Weld Purging Experts, established more than 45 years ago, we are manufacturers
and internationally renowned specialists in field of Weld Purging Technology.
- Pipe Purge Masters PPM
In the ‘Weld’ of Parts Per Million PPM Pipe Purging Masters Product Experts lead through
innovation in Weld Purging Technology.
- Weld Purge Monitors
We boast seven high quality Weld Purge Monitors® for every application and budget.
- Pipe Weld Purging Systems
Creating the perfect solution for every weld purging task.
Check out our website today ....

WWW.PIPEPURGINGMASTERS.COM

PRODUCT NEWS 7

QWIK-FREEZER™ FOR DOWNTIME MAINTENANCE

The Pipestoppers® Division at Huntingdon Fusion Techniques HFT® provides a cost saving solution
to carrying out repairs or modifications on pipes with liquid inside, ideal for companies carrying out
essential maintenance during downtime.

Qwik-Freezer™, the industry sPtaipnedaFrrdeepzoirntagbSleyCstOem2 PcipaepaFbrleeeozifnmg aSkyisntgemicerepqluuigressinlitptleipseest-uupp time
and is the only low cost CO2 to 8”
(200 mm) diameter.

Qwik-Freezer™ kit is easy to use. A specially designed jacket
is wrapped around the pipe at the point where the freeze is
required and sealed at the ends. A nozzle on the jacket is
tpbhereetwnssecueornuepthhleoedseQt.owWaikh-ceFynrlientehdzeeerlriq™ouf ildjiaqCcukiOde2tCiasOnin2djbepyciptmeed,eaiitnntimos tmohfeeadsihpaiatgechley-
expands to form a solid carbon dioxide (dry ice) at a
temperature of -78ºC (-109ºF). This low temperature quickly
freezes the contents forming a secure “ice plug” which seals
the pipe.

The Qwik-Freezer™ ice plug forms only in a section of pipe covered by the jacket so the resulting
rise in pressure is very small and there is no damage to the pipe. The Qwik-Freezer pipe freezing kit
can be used safely on iron, lead, stainless steel, copper, brass and plastic pipe.

Case Study: Low-cost accessory obviates power station shutdown.

A new compressor installation, to be completed within a short window of time, was going well until
a problem was discovered. The design drawings failed to show that a cold water valve extension
handle clashed with the air inlet pipe of the compressor. Critically, this was the only isolating valve
from the cooling water main header and could not be moved without closing the cooling water
system.

This would have also meant shutting down the whole power station, which was not an option.
Potential solutions included re-routing the inlet pipework of the compressor and contracting in a
specialist pipe freezing company to enable the valve to be moved. All initial potential solutions would
have taken time to organise, which could have affected the timely completion of the project.

Freezing was considered to be the best option but this valve was welded into place and freezing
would have to be made far enough up stream not to be adversely affected by the applied heat from
the grinding and re-welding operations. As the water pipe was 75 mm diameter, it was not possible
to acquire one of the commonly available domestic or commercial plumbers’ freezing kits, as these
only have a capacity up to 50 mm. As time was of the essence, an Internet search discovered a Pipe
Freezing Kit for 3” pipe available from the Pipestoppers® Division of Huntingdon Fusion Techniques
HFT®.

The HFT® Technical Team were quickly able to reassure us that Qwik-Freezer™ Pipe Freezing
Systems were a proven option for this size of pipe and within 24 hours we had a kit in our possession.
wInosrtkaelladtiwonellw, ataskeinagsyaraonudndCOan2 bottles were obtained from the local BOC gas supplier. The freeze
hour to freeze the pipe. This freeze allowed time to grind out the
welded valve, plus a length of pipe, re-weld a flange back onto the pipe at a new position and install
a new valve. The job took around two hours to complete in total and at cost of around 25 per cent
of a specialist contractor.

8 PRODUCT NEWS

WELD PURGE FILM FOR A VARIETY OF PIPE SIZES

Low cost weld purging a variety of tubes and pipes sizes can be
achieved by the use of Weld Purge Film®.
Weld Purging Experts, Huntingdon Fusion Techniques HFT®
recommend switching home made dams produced of unsuitable
material, to their low cost Weld Purge Film® to achieve oxide
free, zero colour welds.
Ron Sewell, Chairman for HFT® said: “Weld Purging can be
challenging as well as expensive, which is why many welders
today continue to construct their own dams to cut costs. Homemade dams made from material
such as foam, sponge or cardboard etc., can often lead to loss of welds when they leak or slip from
position thus flooding the welding zone with air.”
“Our Weld Purge Film is great for when mechanical purging devices cannot be retrieved. The Film,
which does not contain water, unlike paper and sponge products do, can be used to create an
impermeable barrier, but can be easily washed away after use without leaving any residue.”
The water-soluble Weld Purge Film® allows dams to be cut easily with the safety knife provided and
once they are fixed into position using the water-soluble Weld Purge Super Adhesive® provided,
produce an impenetrable purge barrier that can easily be washed away during hydrostatic testing of
the pipe or just by normal wash-out.
1. Weld Purge Monitor for On-Site Conditions

RELIABLE OXYGEN ANALYZER FOR WELDING TITANIUM

When welding titanium, it is essential that the oxygen level surrounding the weld is purged down to
as low as 50 ppm. Measuring the oxygen level with a reliable oxygen analyzer is the most efficient
way to know exactly when to commence welding.
Specifically designed for Purge Chamber welding, the PurgEye® Desk is leading the way in inert
gas purging technology by reading oxygen levels from 1,000 ppm, right down to levels as low as
1ppm (highly accurate to 10 ppm), ensuring oxide free, zero colour welds are achieved time and
time again.
Manufactured by Huntingdon Fusion Techniques HFT®, the PurgEye® Desk is equipped with
HFT®’s revolutionary PurgeNet™, for the in-line connection of additional accessories that allows
the Weld Purge Monitor® to control welding systems based upon oxygen level as well as to provide
indications of high and low oxygen levels. These include a Visual
Alarm and a Dew Point Sensor.
Ron Sewell, Chairman for HFT® said: “Our Flexible Welding
Enclosures, together with our PurgEye® Desk are in use
throughout industries such as the aerospace, racing car and
titanium bicycle manufactures where titanium parts are required
to be welded in an atmosphere where the oxygen level is
required to be 50 ppm or less.”

TECHNICAL ARTICLE - THE FUTURE FOR WAAM 9

THE FUTURE FOR WAAM

An acronym for Wire Arc Additive Manufacturing, WAAM is one of several prominent 3-D printing
techniques where significant advances have been made in the last five years. Already established
as an alternative production process in the airframe industry WAAM is now making an impact in
other manufacturing sectors.
Already attracting massive investment across the world, a recent estimate of from the International
Data Corporation indicates that global spending on 3-D printing will grow to $23.0 billion by 2022.
This is an increase of over 23% from 2018. China, the UK and the USA spearhead the drive to
exploit the potential for 3-D printing but Australia, India and the rest of Europe are also actively
examining applications.
Essentially, 3-D printing involves the progressive deposition of material under computer control to
generate a three-dimensional structure. Because the material source is very small and control is
extremely accurate the process offers the potential to produce near-finished complex shapes that
are difficult if not impossible to create by any other technique.
Wire Arc Additive Manufacturing employs an electric arc as a heat source and metal as the deposition
material. Standard arc welding equipment coupled with readily available filler alloys coupled with a
routine multi axis robot means that a system can be purchased for little over $100,000.
The concept of metal deposition using arc welding is not new. Over 50 years ago the process was
used for cladding operations in which thick coatings were added to low alloy steels to improve
corrosion or wear resistance. WAAM employs the same arc welding processes (GTAW, GMAW or
PAW) but under much more precise computer control.
Previously focused on aerospace there is now growing interest from the automotive, marine,
motor sport, renewable energy, oil and gas, and nuclear sectors. At Cranfield University in the UK
for example there are more than 60 ongoing projects, totalling more than £3.5 million, involving
almost 30 staff and MSc / PhD students; some are in collaboration with other universities such as
Manchester, Birmingham and Nottingham. The work is in part funded by organisations such as
Airbus, BAE Systems, United Technologies Research Centre and Lockheed Martin;
The WAAM process promises to make a reduction in the cost of parts by reducing material wastage
and time to market, as well as offering the benefits of increased freedom of design and part complexity,
and customisation. Thanks to low capital and operating costs, WAAM is a much cheaper process
when compared with other 3-D techniques such as laser, electron beam wire or powder-based
additive manufacturing.
A recent major additive manufacturing conference in Detroit included 150 sector experts on
processes, applications, materials and research. They highlighted how these 3D technologies can
cut costs, reduce time to market, produce stronger and lighter parts, improve efficiency and create
complex geometries without sacrificing strength. A case study of a 2.1m tall additively manufactured
excavator arm with a final error of 1mm was introduced.
Aerospace Applications
The early application areas have been in aerospace and several prominent examples are available
to illustrate the dramatic developments.

10 TECHNICAL ARTICLE - THE FUTURE FOR WAAM

One of the largest 3D metal titanium parts in the UK has been
produced by Cranfield University. Measuring 1.2m in length.
The part forms a main structural element (Fig 1) of an aircraft
wing structure and took just 37 hours to build from a digital
model, where previously this process would have taken weeks.
An even larger aluminium wing part measuring over 2.5m in
size has also been produced in less than one day.
Fig 1. Main structural element of aircraft
The world’s largest and fastest metal 3D printer to date has wing. 1200 x 500 x 100 mm. Material:
been manufactured by Titomic Ltd in Australia and is capable titanium alloy. Image from Sciaky.

of making complex aircraft wing parts of up to 9m in length. It can also print metal bicycle frames in
around 25 minutes. The company is also using the additive manufacturing process to produce wear-
resistant coatings for the mining industry.

Spirit AeroSystems recently began installing the Boeing 787’s first
titanium structural component, made by Norsk Titanium (Fig 2).
Feedback from Boeing notes that the real wins won’t involve just
material reduction; they will include part weight, reduction in assembly
time by consolidating systems into single 3D-printed forms, and faster
time-to-market as a result of reducing the number of manufacturing
steps.

Fig 2. Door latch fitting for the Boeing 787 Dreamliner.

Marine Applications

Casting is the traditional method used to create marine propellers, but it requires long lead times
since the process involves making a mould, casting it, and then processing it. Most forging and
casting companies are no longer located in Europe, which means even more time is needed to
obtain parts. Additionally, most of those companies require orders for quantities larger than one part,
which means warehousing a large stock of components that may never be used.

Automotive Applications

WAAM affords the possibilities of producing complex parts for vehicles that may not be possible with
traditional manufacturing techniques. This is particularly attractive in sectors such as motor sport
and specialist road vehicles where production runs are
limited and cannot take advantage of cost reductions that
come with volume manufacture. The process even offers
the opportunity to produce prototypes on a one-off basis
quickly and cost-effectively.

Car manufacturer Audi is taking advantage of the benefits
of metallic 3D printing in collaboration with SLM Solutions
Group AG. (Fig 3)

Limitations on further application of WAAM Fig 3. Metal water connectors for the AUDI W12 engine

Deposition Rates

Early uses of metal additive technology were restricted to small components because of the very low
deposition rates and the resultant long and therefore expensive manufacturing times.

TECHNICAL ARTICLE - THE FUTURE FOR WAAM 11

Rapid development by the WAAM industry generally has led to current rates of 15 kg/hr being
realised with many metals. Whilst this may not appear noteworthy it brings the process into line
with alternative manufacturing methods whilst at the same time offering opportunities for producing
complex shapes in small runs and this is now leading to exploitation by an ever-widening industrial
arena.

Component Size

Limited availability of large dimension 3-D computer numerical control equipment has restricted
growth of direct metal deposition but recent developments, particularly by the aerospace industry,
have expanded the scope considerably. Work at Cranfield University has achieved a milestone by
depositing a 6-metre long spar using the WAAM process and an aerospace-grade aluminium alloy.
The 300-kg, double-sided spar was built at the university’s 10-metre deposition facility. This trend
seems likely to continue with similar facilities in Australia, USA and Spain.

Precision

Whilst the early applications of WAAM included the use of multi-axes robots, the positioning accuracy
falls well short of that available with specialist computer numerical control equipment. A typical robot
can offer precision of between 0.5 and 2 mm whereas a cnc facility might claim to be ten times more
accurate. The final decision will be one of cost and space – robots are much cheaper and more
compact.

Protection Against Oxidation

The use of high metal deposition rates brings with it the problem
of protection of the metal from oxidation during the fusion
and cooling cycles. Local protection using standard shields
is often inadequate but specialist equipment suppliers have
developed flexible enclosures capable of providing an inert gas
environment. Fabricated from engineering plastics and using
advanced sealing technology these enclosures can be large
enough to accommodate a complete WAAM system (Fig 5) and
provide a gas environment with an oxygen content as low as 20
parts per million – more than adequate to protect even the most
sensitive materials from oxidation.
Lack of Awareness Fig 4. 27 cubic metre flexible enclosure from
Huntingdon Fusion Techniques, installed at Cranfield
University and containing a complete WAAM facility.

The success of 3D printing generally has been publicised widely but the emphasis has been almost
exclusively on a phrenetic outpouring of the more exciting applications such as those in the medical
and biomedical sectors. Despite success in the demanding aerospace industry, full engineering
potential has so far gone largely unrecognised.

The proven application of WAAM in the aerospace, automotive and marine industries should now
be grasped eagerly. The process promises to make significant reductions in the cost of parts by
reducing material wastage and time to market, as well as offering the benefits of increased freedom
of design and part complexity, and of customisation.

Sources of further information:
Additive Manufacture of Large Structures. Bandfari et al. Welding Engineering and Laser Processing Centre, Cranfield University MK43 0AL. Welding
Makes Major Impact on 3D Printing Technology. Fletcher. Huntingdon Fusion Techniques White Paper WP 197. huntingdonfusion.com. What Is
the Role for Additive Manufacturing in Aircraft Structural Components? Zelinski. Additive Manufacturing. March 2019. Video: WAAM Casts Away
Traditional Large Manufacturing Methods. Heimgartner. Engineering.com. April, 2018.

Eliminate the Thoria and Maintain the
High Performance with Blue-Tipped

MultiStrike® Tungsten Electrodes

Scientific Developers of
Weld Purging Technology and

Manufacturers of
Weld Purging Products since 1975
Celebrating our 45th Anniversary

www.huntingdonfusion.com