Novarc Technologies’ SWR+HyperFill uses Lincoln Electric’s twin-wire gas arc welding technology to perform filler and cap passes in pipe welding.
Welding pipe sections is a complex job. Diameter and wall thickness vary slightly; it’s just the nature of the beast. This makes assembly an act of compromise and welding an act of adaptation. The process is not easy to automate, and good pipe welders are rarer than ever.
The company also wants to retain good pipe welders. A good welder may not want to place the pipe in a rotating chuck and continuously weld at 1G for eight hours. They may have tested 5G (horizontal non-rotating ducts) or even 6G (non-rotating ducts in an inclined position) and would like to be able to put those skills to use. 1G welding requires skill but can be tedious for those who have mastered it. This can also take a very long time.
However, in recent years, the spool shop has seen more automation capabilities, including collaborative robots. Novarc Technologies, based in Vancouver, British Columbia, released its collaborative Spool Welding Robot (SWR) in 2016, and in recent months added Lincoln Electric’s HyperFill twin-wire gas arc welding (GMAW) technology to the system.
“This gives you a larger arc column for welding with higher deposition. The system features rollers and a special contact tip so you can run two wires in one conduit and create a larger arc cone, allowing you to deposit nearly twice as much weld. ”
said Soroush Karimzadeh, CEO of Novarc Technologies, which presented SWR+Hyperfill technology at FABTECH 2021. For pipes [walls] ranging from 0.5 to 2 inches in diameter, you can still get comparable settling rates. ”
In a typical installation, the operator sets up the cobot to make a root pass using one welding torch and one welding torch as usual, then removes the welding torch and replaces it with another welding torch with a two-wire GMAW setting. This increases the application of filler and the passage of the lid. “This helps reduce the number of welds and reduce heat input,” Karimzadeh said, adding that controlling heat helps improve the quality of welds. “In our internal testing, we were able to obtain high impact test results down to -50 degrees Fahrenheit.”
Like any shop, some pipe repair shops are quite a mixed bag. They rarely process thick wall pipes, but they do have an under-arc system sitting idle in the corner in case such a job comes up. Using a cobot, operators can use a single-wire setup for thin-walled pipes and then switch to a dual-torch setup (single-wire for root canals and twin-wire GMAW for potting and capping) when processing thick-walled pipes. this previously required sub-arc welding system piping.
Karimzadeh adds that dual-burner units can also be used to increase flexibility. For example, a collaborative robot with two torches can weld carbon and stainless steel pipes. With this arrangement, the operator will use two burners in a single-line configuration. One torch can feed wire for carbon steel applications and the other can feed wire for stainless steel pipes. “In this configuration, operators equip a second torch dedicated to stainless steel with a wire feed system that does not allow contamination,” says Karimzadeh.
The system reportedly allows changes to be made quickly during a critical root pass. “During root cutting, as you go through the tacks, the gap will increase or decrease depending on the fit of the pipe,” explains Karimzadeh. “To enable this, the system can detect sticking and perform adaptive welding. That is, it automatically changes the welding and motion parameters to ensure that the welds are connected correctly. It can also read how the gap is changing and change the driving parameters to confirm this. don’t go through to get a proper root pass.”
The collaborative robotic system combines laser seam tracking and a camera that allows welders to clearly see the wire (or wire in a two-wire setup) as the metal flows into the groove. Over the years, Novarc has used welding data to create NovEye, an artificial intelligence-powered vision system that makes the welding process more automated. The goal is to free the operator from constantly watching the weld and instead allow him to step away and perform other tasks.
Compare all of this to an application that involves a manual root pass, followed by a quick pass using a grinder, and a manual hot pass to clean the surface of the root pass. After this, the pipe section is finally moved into the filling and capping channel. “This usually requires moving the pipe to a separate station,” adds Karimzadeh, “and therefore requires more handling.”
Now imagine the same application with collaborative robot automation. The cobot uses a single-line setup for both the root and closing passes: welds the root and then immediately begins filling the bead without stopping to grind the root. For thicker pipes, the same station may start with a single-wire torch and then switch to a double-wire torch for subsequent passes.
This kind of collaborative robot automation can change life in tube and spool shops. Professional welders spend most of their time on the most difficult pipe welds that cannot be made on a rotating chuck. Beginners will work alongside veterans to operate a cobot, view and control welds, and learn what good pipe welding looks like. Over time (after practicing in the 1G manual position), they learned to operate the welding gun and eventually passed the 5G and 6G tests, becoming proficient welders.
Today’s aspiring cobot operator may be taking a new path in his pipe welding career, but being new doesn’t make him any less effective. Additionally, the industry needs good pipe welders, especially ways to improve the productivity of these welders. In the future, pipe welding automation, including collaborative robots, is likely to play an increasingly important role.
Tim Heston is a senior editor at The Fabricator. He has been covering the metalworking industry since 1998, beginning his career at the American Welding Society’s Welding Magazine. Since then, he has mastered the full range of metal fabrication processes, from stamping, bending and cutting to grinding and polishing. He joined The Fabricator team in October 2007.
Fabricator is the leading magazine for the North American metal fabricating industry. The magazine publishes news, technical articles and case reports that enable manufacturers to do their jobs more efficiently. The manufacturer has been serving the industry since 1970.
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Post time: Jun-14-2024