Pipe welding progress

“The PIPEFAB welding system is Lincoln Electric’s culmination of the best pipe-specific welding outputs with intuitive, straight forward and simple controls, in a ready-to-run design that minimizes the welders’ setup times,” said Brian Szenasi, Alberta district sales manager, Lincoln Electric. Lincoln Electric

Incremental change is common in manufacturing, particularly in pipe welding. If you have process parameters for a pipe weld, for instance, changing those parameters to introduce a new welding process can be more trouble than its worth. That’s why tried and true welding methods live longer in some segments of the industry than others. If it’s not broke, don’t fix it.

But as new projects come online, welding equipment manufacturers are developing new technology that can help shops increase productivity and the precision in their welds.

Stability and Traceability

Whether in the shop or in the field, getting the root-gap weld right is key to a successful pipe weld procedure.

“Our TPS/i is a MIG/MAG system that is ideal for laying that root weld,” said Mark Zablocki, welding application technician, Fronius Canada. The TPS/i is Fronius’ scalable system for MIG/MAG processes. It has a modular design so that it can be scaled up as necessary for manual or automated use.

“For TPS/i we developed a system called LSC, which stands for ‘low spatter control,’” said Zablocki. LSC is a modified short-circuit transfer arc with high arc stability. The process is based on the short circuit occurring at a low current level, which leads to a gentle reignition and a stable welding process. This is possible because the TPS/i recognizes and reacts quickly to the process phases occurring during the short circuit. “We achieve a short arc with enough pressure to add root reinforcements. The LSC creates a very soft arc that is easier to control.”

A second iteration of LSC, LSC Advanced, helps improve process stability when you are working further away from your power source. Long cable runs lead to increased inductivity, which in turn causes more spatter and decreased process stability. LSC Advanced manages this issue.

“When you start getting very long connections between your contact tip and your power source—around the 50-ft. range—that is when you start using LSC Advanced,” said Leon Hudson, technical support national manager, perfect welding business unit, Fronius Canada. Like many modern welding machines, Fronius’ are equipped to document each weld.

“You can develop the criteria for your weld parameters and lock those into the machine,” said Hudson. “The machine can be equipped so that only a welding supervisor can access those parameters with a key card. With those parameters in place it’s possible to trace the kilojoules per inch you’ve performed on each weld to ensure you meet the proper codes.”

While TPS/i is very effective with a tightly controlled root weld, to produce faster welds on fill passes, the company has designed its pulse multi control (PMC) process. This pulsed-arc welding process has high-speed data processing that can keep pace with a faster weld while still maintaining a stable arc.

“The welding machine to a certain extent compensates for the operator’s stick-out changes to ensure constant welding penetration,” said Hudson.

Designed for applications in the semiconductor, pharmaceutical, nuclear, and other premium pipe fabrication operations, AMI’s M317 orbital welding controller has advanced controls and a touchscreen interface to simplify automated welding. ESAB

On automated welding in a shop, where the hot passes are performed in the 1G position while the pipe rotates, PMC stabilizers can adjust automatically to account for highs or lows on the pipe surface.

“The TPS/i welding machine monitors the arc performance and is able to adapt in real time,” said Zablocki. “As weld surface fluctuates around the pipe, the volts and wire speed are adjusted in real time to ensure a constant current.”

Stability and increased speed is at the heart of many technology upgrades that are helping pipe welders in their day-to-day operations. While all of the above relate to MIG/MAG applications, similar efficiencies are being found in other processes such as TIG.

For instance, Fronius’ ArcTig for mechanized processes can speed up processing of stainless steel tubing.

“Stainless can be tricky as it doesn’t dissipate heat well and has a tendency to deform,” said Zablocki. “Usually when performing a weld on stainless, the most you can hope for in terms of penetration in one pass is 3 mm. But with ArcTig, the tungsten is water-cooled, which creates a more focused arc and greater arc density at the tip of the tungsten. The arc density is so much stronger that you can weld up to 10 mm at full penetration with no preparation.”

Hudson and Zablocki are quick to point out that every application suggestion they make in the field starts with the customer’s procedures and which technology fits those requirements. In many cases, new technology provides more stability, efficiency, and the opportunity for rich data to ensure the job is completed correctly.

Bundling Key Processes

With its PIPEFAB welding system, Lincoln Electric aimed to create an equipment setup to simplify processes for the pipe welding and vessel fabrication industries.

“We have numerous different pipe welding technologies that exist across multiple machines; with the PIPEFAB welding system, we took a focused approach to take all of those different technologies that could benefit pipe welding and we put them in one package,” said David Jordan, director, global industry segments, pipe mills and process industries, Lincoln Electric.

Jordan points to the company’s Surface Tension Transfer (STT) process as one example of the technologies included in the PIPEFAB welding system.

“The STT process is ideal for doing an open-gap root pass on pipe,” he said. “It was developed 30 years ago for welding thin-gauge material because it supplies a very controlled arc transfer, with lower heat input and low spatter levels. In the intervening years we have found it works very well for that root pass in pipe welding.” Jordan adds, “In the PIPEFAB welding system, we have taken the legacy STT process technology and refined the arc further to optimize operating characteristics and speed.”

The PIPEFAB welding system is also equipped with Smart Pulse technology, which monitors your machine settings and automatically tailors the pulsed welding output to deliver the ideal arc for your job.

“If I have a low wire feed speed it knows I am using a low-energy process, so it is going to give me a very crisp, focused arc, very specific for low-wire feed speeds,” said Jordan. “As I turn that feed speed up, it is automatically going to call up a different wave shape for me. The operator doesn’t need to know this, internally this just happens. These settings allow the operator to focus on the weld rather than worrying about technical adjustments on the job.”

The aim in developing this system was to create one machine that could allow welders to do everything from the root pass to the fill and cap on one machine.

“It’s very easy to switch from one technique to another,” said Jordan. “We have a dual feeder on the PIPEFAB welding system, so you could run your STT process for the open-gap root pass on one side of the feeder with an appropriate gun and consumables—you need a tapered tip to run that root pass, and a lighter weight gun for more dexterity—and then on the other side you would be equipped to run your fill and cap passes, whehter flux-core, solid-core, or metal-core wire.”

You also don’t have to disconnect cables to switch out processes.

“If you are putting down an 0.35-in. (0.9-mm) STT root with solid wire and a fill and cap with 0.45-in. (1.2-mm) metal-core wire or flux-core, you just keep both consumables set up on either side of the dual feeder,” said Brian Szenasi, Alberta district sales manager, Lincoln Electric. “The operator puts in the root, then picks up the other gun without touching the machine. When he pulls the trigger on that gun, the system automatically switches over to the different process and weld settings.”

While it was important to offer new technology on the machine, it was also important to Lincoln and its customers that the PIPEFAB welding system could handle traditional pipe welding processes as well, such as TIG, stick, and flux-cored.

“Customers will certainly want to take advantage of the advanced STT technology for solid-wire or metal-cored roots and Smart Pulse. While new processes are front and centre, customers still have traditional or legacy procedures that they use occasionally,” said Szenasi. “They need to still be able to run a stick or TIG process. Not only does the PIPEFAB welding system offer all these processes, but the Ready-to-Run design has dedicated connections, so your TIG torch, stick stinger, and welding guns remain connected and good to go at all times.”

Another recently released technology that can serve as an upgrade on the PIPEFAB welding system is the company’s HyperFill twin-wire MIG system, which increases deposition rates substantially.

“We have found over the past year and a half that HyperFill technology is very effective in pipe spooling applications,” said Jordan. “If you add a water cooler and use a water-cooled gun, you can now run this twin-wire process for fill and cap. We are able to achieve deposition rates of between 15 and 16 lbs./hr., whereas with our best single-wire process we hit 7 to 8 lbs./hr. So it is capable of more than doubling deposition rates in the 1G position.”

The PIPEFAB welding system is notable for what it strips away as well.

“Our Power Wave series of machines are popular and powerful, but there are waveforms included in those machines that wouldn’t be needed in a piping shop,” said Szenasi. “Things like aluminum- and silicon-bronze wave shapes have been removed to focus on the waveforms that will really bring value in a pipe welding facility. The PIPEFAB welding system has wave shapes for steel and 3XX stainless steel, solid-wire, metal-cored, flux-cored, SMAW, GTAW, etc.—all the modes you would want to weld pipe.”

There is also no need for a sense lead. The company’s Cable View technology continuously monitors cable inductance and adjusts the waveform to maintain consistent arc performance with long or coiled cable runs up to 65 ft. This allows the system to make the proper adaptive changes on the fly to ensure the arc performance is robust.

Like many new systems, data acquisition is straightforward as well.

“Cloud-based CheckPoint Production Monitoring can be set up so that a supervisor is automatically sent a message if a machine drops below a certain performance threshold. CheckPoint Production Monitoring allows you to close the loop on process improvements, so once you implement a change you can control and verify the improvement” said Szenasi. “Data capture continues to grow in popularity, customers are certainly discussing the opportunities this creates for them to better manage their business.”

Orbital Welding Controls

Companies are doing what they can to upgrade already sophisticated automated welding processes, using the ability to gather data from operations to enrich process feedback mechanisms. The M317 orbital welding controller from Arc Machines Inc. (AMI), an ESAB brand, is an example of this.

Designed for applications in the semiconductor, pharmaceutical, nuclear, and other premium pipe fabrication operations, it has advanced controls and a touchscreen interface to simplify automated welding.

“Previous orbital TIG welding controllers were really designed by engineers for engineers,” said Wolfram Donat, chief software architect, AMI. “With the M317, we had welders show us what they needed from it. We wanted to lower the barriers to entry into pipe welding. It can take a week to train someone to operate an orbital welder. It might take months for them to be fully comfortable with it, and as much as two years to get the ROI out of the system. We wanted to shorten that learning curve.”

The controller receives data from different sensors that allow operators to control their welds in a variety of ways. Touchscreen features include an automated pipe schedule generator. A schedule editor allows operators to adjust, fine-tune, add, delete, and navigate amperage levels. Once in welding mode, a data analytics engine provides live data while cameras offer a live view of the weld.

Paired with ESAB’s WeldCloud and other orbital analytics, users can collect, store, and manage data files locally or on the cloud.

“We wanted to create a system that wasn’t one generation from being obsolete, but instead can serve the needs businesses will have in the future,” said Donat. “If a shop isn’t ready for cloud-based analytics, they can still get data from the machine because it is housed locally. When analytics become important, that information will be there for them to mine.”

Right now, it can be useful to track and trace weld concerns.

“The M317 combines the video image with the welding data, timestamps it, and saves a welding record,” said Donat. “If you’re performing an extended weld and you find irregularities, you don’t necessarily have to discard the weld because you can go back and see every instance where your system has highlighted an issue.”

The M317 has modules for accommodating different frequencies of data recording. For applications such as oil and gas and nuclear power, the frequency of data recording may depend on the quality of a particular component. To qualify a weld, a third party may need precise data to show there was no irregularity in the weld from the current, voltage, or anywhere in the welding process.

What all of these companies demonstrate is that welders have ever greater amounts of data and feedback mechanisms to create better pipe welds. The future looks bright with these technologies.

Editor Robert Colman can be reached at rcolman@canadianfabweld.com.

ESAB, www.esab.com

Fronius Canada, www.fronius.ca

Lincoln Electric Canada, www.lincolnelectric.ca