Pounding the Metal
- May 1, 2022
In search of “massive” productivity gains in process pipe welding
The game of professional football and process pipe welding may not seem to bear any similarities. But they do share a single important one. Football has long been described as a “game of inches.” Welding pipe is also a game of inches, specifically “diameter inches per day,” the key measure of productivity for a shop’s process piping operations.
The average for manual welding shops is 65-80 diameter inches per day. Top performing shops average 80-100 diameter inches per shift. A world class operation, however, can run at 100 diameter inches or better per day.
How can you get your pipe welding operations performing among the best? David Jordan, global industry segment director, pipe mills and process industries for Lincoln Electric and Rick Campbell, vice president sales for Novarc Technologies, believe investment in a twin-wire MIG solution, particularly when coupled with automation, provides a breakthrough in the magnitude of a three to eight-fold increase in productivity. The two collaborated on a recent webinar entitled Introduction to Collaborative pipe spool welding robots and high deposition HyperFill technology, hosted by CWB Group’s BC chapter.
“At the end of the day, it really is about pounding in that metal as quickly and as accurately as possible. It’s about time savings. It’s about accuracy,” said Campbell. “You have to figure out (what investment in such technology) is going to do for your business. When you think of increasing productivity three to eight times, it’s about reducing the costs in your bids. Or, if you’re deploying this on a project that you’ve already won, you’ve just blown up your margins massive by being able to reduce the overall time of execution.”
But before we can judge whether reality lives up to the hype, let’s begin with an introduction to the technologies Campbell and Jordan are referring to.
The HyperFill welding process was designed by Lincoln Electric and released about three years ago. Originally designed for welding in heavy fabrication industries, it was developed into a process for many industries and applications, including process piping for the 1G (horizontal rolled) position. It’s a twin-wire MIG solution, designed to run with Lincoln Electric welding wire. The advantage provided by HyperFill’s twin wires is the formation of a liquid bridge as the two wires melt off a single droplet, leading to high deposition rates.
“Because we are using two wires to generate that droplet, the droplet is actually larger (than it would be if using a single wire) and the arc cone is wider and the resulting penetration profile is wider as well,” Jordan says. “The wider arc cone more evenly distributes the arc energy, making the arc more stable so we are able to travel at the leading edge of the puddle and we can get much faster travel speeds.”
Jordan adds that the advantage of the twin-wire process is not just that it creates high deposition rates but that it creates high “useable” deposition rates. Single wire MIG reaches a saturation point where the arc becomes unstable so you can’t turn the speed up any higher.
Jordan also points out that although HyperFill uses two wires, it still only requires a single power source, wire feeder, water cooler, gun liner, contact tip and high-performance engineered GMAW wire.
“It is almost the same as a single GMAW wire set-up,” he says.
The HyperFill process is not for all process piping. It has its sweet spot for productivity gains over single wire MIG. That sweet spot is in piping in the range of 150-610 mm (6-24 in.) in diameter with a wall thickness of 11-25 mm (0.432 – 1 in.) at the 1G position.
The increase in productivity compared to other processes is “quite dramatic”, says Jordan. Lincoln Electric’s own estimates are that traditional processes – GTAW, SMAW, GMAW, FCAW, GMAW-P – produce deposition rates of 3-8 lbs/hr on process piping at the 1G position. HyperFill can produce a deposition rate upwards of 15 lbs/hr. As impressive as that is, the productivity gains are even greater when Hyperfill is coupled with an automated system.
Novarc’s Spool Welding Robot (SWR) is the first automated solution that Lincoln Electric has combined with HyperFill. Novarc is a north Vancouver-based company that started in 2013 serving oil field service companies, mechanical contractors and engineers and the shipbuilding industry, predominantly in North America. It has experienced near 100 per cent year-over-year growth the last three years, according to Campbell.
“It’s those industries that are looking at us and saying how can we become more competitive in the markets we serve? What they found is that they’re able to weld faster with us, they’re reducing their repair rates so they’re welding better,” says Campbell.
Novarc’s SWR is designed for pipe fabrication and can support roll welding requirements of pressure vessels and process pipes under significant standards such as ASME B31.1 and B31.3 for pipes, elbows, neck and slip-on flanges. SWR productivity with a single wire welding process reaches 200-350 diameter inches per shift. Add Hyperfill’s twin-wire technology and productivity can shoot up to 500 diameter inches per shift.
“It’s a massive, massive jump in what you can typically experience in a shop. Think of having three to five times the productivity,” Campbell says.
Of course, increasing productivity is pointless if in the process of going faster you reduce quality, adds Campbell. Manual welding operations in North America average a 3-5 per cent repair rate with top performers capable of a 1-2 per cent repair rate. SWR quality is capable of a less than 1 per cent repair rate.
“If you’re running 6,000 pipes through this in a year with a 3 per cent repair rate, that’s 180 pipes you have to x-ray, tear down, redo and re x-ray again. It’s about $1,000 per pipe so there is about $180,000 in repair costs going out the door. Even if you move that 2 per cent to the left, you’ve just saved $120,000 per year on repairs alone,” Campbell says.
Every time the weld is on, the SWR system records it. The system also records all the parameters that are built into the weld, providing accountability and traceability.
“All that info and the quality control side of it is then allowing business development managers, who are going out and quoting on jobs, to take real quantifiable data and be more competitive when bidding on projects. It gives you that leg up and allows you to start taking greenfield opportunities away. It allows you to change the game from what you are doing,” Campbell asserts. SMT