MORE ABOUT BUTT WELDING MACHINES
What is butt welding?
Butt welding is the principal method used for joining HDPE pipes and fittings. To perform a butt weld correctly and consistently, you will require a butt welding machine capable of aligning the elements to be welded, shaving their ends smooth and parallel, uniformly melting the ends of the pipe under various pressures, then pushing the ends together at a controlled pressure for a specific period.
Australian and international butt welding standards
Various International and National Standards exist for butt welding, where the temperature/pressure/time profile of the weld is detailed. Some of the most relevant for general use are:
- ISO 21307-2017, Butt fusion jointing procedures for polyethylene (PE) piping systems
- ASTM F 2620 – 20, Heat Fusion Joining of Polyethylene Pipe and Fittings
- ASTM F 3124 – 15, Data logging of butt welding
- DVS 2207-1-13, Welding of thermoplastics - Heated element welding of pipes, piping parts and panels made out of polyethylene
The ISO Standard covers butt welding of metric pipe and is relevant in most of the world. ASTM Standards are for IPS & DIPS (inch) pipe which is specific to North America, while DVS is a well-respected and conservative standard from the German Welding Institute, successfully specified world-wide.
Sizes of butt welding machines available
Worldpoly manufacturers butt welding machines to weld HDPE pipes from 40mm to 3000mm OD. However, HDPE pipe and fittings of any diameter can be butt welded, but diameters beneath 63mm are not generally recommended as it becomes difficult to align the pipe ends accurately and consistently within the specifications of the relevant standard. Although Worldpoly manufactures machines to weld down to 40mm, when a welded joint is required, the preference for small diameters is to use electrofusion. Large diameter pressure and non-pressure pipes to 3000mm and above are now regularly welded, with fittings machines already producing to 2000mm/80”.
Types of butt welding machines
Two distinct styles of field butt welding machines are produced. These include what is commonly known as a ‘European style’ and ‘North American style’ machine.
- European style: The most popular and by far the lowest cost are the ‘European style’ machines, where the welding carriage and hydraulic power unit are separate, as is the stand carrying the facing tool and heating plate. As the facing tool and heating plate must be inserted and removed manually, larger butt welding machines are available with attached jib cranes for this purpose, or an available excavator bucket is used for the heavy lifting.
- North American style: These butt welding machines have all required components on-board the main chassis, so movement on tracks or wheels is easier, and tracked machines have their own diesel engine power supply.
Features and benefits of Worldpoly butt welding machines
'European Style' Machines
- Designed and Engineered in Australia, to reflect the true requirements of the market
- Pipe OD is not within manufacturers tolerances, so the machine must re-round it for welding. Our main clamps are heavier because of that, and yes, that costs us.
- Electrical wiring is done according to the requirements of the IEC, which is not the case with low-cost copies. Good luck if somebody is electrocuted using one of those.
- Worldpoly hydraulics are sized according to real-life, not theory. Most clients weld 12 metre, not 6 metre lengths as is the case in Europe, and real-life contractors not in Europe have their own ways, so our hydraulics provide the power you need. And yes, you pay for that.
- Our ‘European Style’and workshop machines are produced in China, according to our specific requirements. We’ve been doing that for 20 years and we’re pretty good at it, but we must continue because you won’t pay for us to make them in Australia. Facts are facts. That production centre manufactures exclusively for Worldpoly, is fully integrated with our Australian Design Centre, and produces the best butt welding equipment coming out of China. PolyForce machines are 100% Australian made.
- ‘Fitness for Purpose’ is the Law in Australia, and all of our butt welding machines follow that basic requirement, no matter where we supply them. That’s a very old fashioned attitude, it’s what we are.
- Worldpolys history began with the production of poly pipe in 1959 and has been a part of its use in more that 100 countries, so please, ask any questions from the most basic to material analysis and testing. Wherever you are at in the use of HDPE pipe, we’re sure to have an opinion.
'North American' Style Machines
"North American" style machines have all of the components on-board, with the tracked versions carrying their own power supply.
"European style" machines are by far the most popular world-wide, due to their significantly lower price. On a Dollar for Dollar comparison it looks like a no-brainer, but site location, labour costs and availability, the requirement for speed and accuracy, local health and safety considerations remind me what I was told decades ago ‘the Dollar sign is the last elements of the value equation, otherwise Mercedes Benz wouldn’t exist’. You can buy a machine from us to weld 630mm/24” pipe for AUD 18,000 / USD 15,000 (Worldpoly630), or for AUD 400,000 / USD 300,000 you get a fully optioned PolyForce630i Tracked.
Worldpolys’ PolyForce tracked machines are completely designed, engineered and manufactured in Australia, according to the requirements of our particularly stringent health and safety requirements, difficult environment and climate, and the requirements of clients welding under difficult conditions.
The availability of parts has always been an issue for imported machines, which is why PolyForce uses only locally supplied components. Whatever you need we can take from either work-in-progress or our normal supplier, and have you working ASAP, so there’s no need to cannibalise a $400,000 to keep another one working. If you are in North America our suppliers Rexroth, Danfoss, Yanmar, MecAlte etc. have extensive cover over your way, so were more than happy to do any warranty work with them and your favourite hydraulics or electrical specialist.
Some specifics of our PolyForce Tracked machines are:
- All PolyForce machines are 100% Australian designed, engineered and manufactured, from more than 60 years of experience.
- PolyForce630i Tracked is supplied as a complete machine, no extras. All diameters of liners, data logging, trench kit, no surprises.
- Provides full PLC welding with automatic time, temperature and pressure, semi-automatic and manual welding.
- Easy, intuitive operation removes operator variables.
- Allows welding between clamps 2 & 3, and 3 & 4 for short fittings, fabrications etc.
- Automatic changeover following heating happens in 6 seconds, consistently reducing what is considered to be a significant cause of long-tern weld failure.
- All liner diameters are included with the original machine.
- Data logging to ASTM F3124-15 is included at no cost.
- Equipment for future remote connectivity has been included for a future software upgrade.
- PolyForce1000e provides welding to 1000mm / 36” DIPS, with a greater level of operator control.
- Track motors are ridiculously powerful.
- All diameters of pipe clamps, data logging and trench kit are included.
- Width is transport legal without removing the welding carriage, and it can be driven straight into a shipping container.
- Hands-free open/close/locking of main clamps.
- Uber-tough design and construction.
- More excellent customer service.
Do you provide a poly welding time and pressure chart?
Correct poly welding procedure will follow the requirements of the welding standard specified by your customer, which includes the temperature, time and pressure needed for each step. If these are done correctly, and the pipe is made from the correct material, you can expect the weld to be stronger than the pipe.
A poly welding time and pressure chart has already worked these out for all of the pipe which will fit the machine, providing the temperature, time and pressure required for each one. First the diameter, next the SDR/DR or wall thickness, then all of the times and pressures are shown. Worldpoly provides this on their free app, so please go the Play Store or Appstore and enter ‘Worldpoly’.
Temperature, time and pressure are not the only requirements for a good weld, and we absolutely recommend at least OEM if not international level training for all operators, supervisors and specifiers. If this raises questions, please contact Worldpoly for assistance.
Why HDPE pipe systems?
HDPE pipe systems provide exceptional service, with the gas and water systems installed in countries like the UK expected to provide 100+ years of useful life. Of course installation must be carried out correctly, but as a ductile material the pipe is unlikely to fail when other services nearby are excavated, enlarged or repaired, or other significant soil movement occurs. The same is not the case with rigid pipe systems, excellent examples of which were the Kobe (Japan) earthquake of 1995, and more recently Wellington (New Zealand).
In the past welded HDPE pipe systems were the domain of city gas companies and the mining industry, where the high comparative cost was offset by other significant factors in their value equation. Over the past 15 years a significant increase in the volume of the raw material being produced has reduced the pipes comparative cost significantly, and welding technology has increased dramatically, meaning that today HDPE pipe is now a staple for water, mining, gas, sewer and industrial applications from Norway to Bolivia, Germany to Chad.