Switching from traditional stick welding to advanced wire processes
When your business is transporting, generating and distributing energy, it’s critical to construct and maintain pipelines that keep things running. Unnecessary downtime, lost productivity and rework due to less than optimal weld quality all impact the bottom line.
As a global energy infrastructure leader, Enbridge Inc. operates the world’s longest, most sophisticated crude oil and liquids transportation system. With 17,511 miles of active pipe that deliver an average of 2.8 million barrels of crude oil each day through North American pipelines, Enbridge transports 28 percent of the crude oil produced in North America.
Based in Calgary, Alberta, the company is also a leader in gathering, transporting, processing and storing natural gas — with 34,410 miles of gas pipeline. Enbridge is Canada’s largest natural gas distribution provider, serving about 3.5 million retail customers in Ontario, Quebec, New Brunswick and New York state, and it moves approximately 20 percent of all the natural gas consumed in the United States.
In an operation this large, it’s key to improve productivity and efficiency while also maintaining safety and quality. Welding may seem like a small part of the operation, but it plays a crucial role in the construction, maintenance and repair of large-diameter transmission pipelines. Finding efficiencies in the welding operation can help improve productivity — saving time and money.
Enbridge recently made a change to the welding processes used for pipeline repairs and tie-ins on several of its sites, switching from traditional stick welding to advanced wire processes. The move significantly improved productivity — reducing weld time by 40 percent — allowing Enbridge to meet timelines and complete more construction projects while maintaining its high safety standards.
Enbridge jobsites require welding all standard pipe grades and wall thicknesses, with pipe diameters typically ranging from 20 to 42 inches. Butt welds to join pipes are common, in addition to any large-diameter pipe repairs that are necessary in the field.
In-service repair welding is a critical part of the Enbridge operation across the company’s entire U.S. system of pipelines — with the company using up to 300 welding operators in a given construction season.
The company has qualified welding procedures that comply with both ASME section IX and API-1104 requirements. This allows Enbridge the flexibility to conduct new fabrication welding and in-service repairs in two countries.
Enbridge prides itself on seeking out new technologies to ensure quality and safety on its jobsites, and the welding operation is no exception. With the world of pipeline materials evolving, the need to use low hydrogen processes is rapidly growing and becoming the new norm for many companies.
Wire welding processes were not traditionally used in the field by Enbridge, but the company believed a process change could improve productivity to meet demanding timelines while also meeting the low hydrogen requirements critical for pipeline welding.
A switch to wire welding does not compromise safety
In order to safely fabricate with these pipeline materials and repair legacy assets, Enbridge realized that wire feed welding is a ready-made option.
Although wire feed welding has been around for decades, its use as a primary tool in pipeline welding is relatively new. Enbridge believed that technology advancements in wire feed welding warranted additional study and investment as a viable option for the company’s welding programs.
The company converted from stick welding to advanced wire processes for some of its pipeline repair and tie-ins, using pulsed MIG and Regulated Metal Deposition (RMD®) processes with XMT® 350 FieldPro™ power sources and Smart Feeders from Miller Electric Mfg. LLC.
In a modified short-circuit MIG process such as RMD, the welding system anticipates and controls the short circuit, then reduces the welding current to create a consistent metal transfer. Precisely controlled metal transfer provides uniform droplet deposition, making it easier for the welding operator to control the puddle. Advanced welding processes such as pulsed MIG or modified short-circuit MIG are also more forgiving to variations in stickout and result in a calm stable arc, which makes it easier for operators to control.
In choosing the welding system for the wire processes, reliability and versatility were key considerations for Enbridge because projects often have demanding deadlines and are completed in harsh environments. The company wanted equipment that allows welding operators to consistently produce high-quality welds. An easy-to-use interface was also a priority, allowing welding operators to focus on welding versus worrying about manipulating parameters or dialing in the machine to achieve the right results. When welding operators can rely on the performance of their equipment, they can devote their attention to safely completing a quality weld — the focus is on safety and craftsmanship.
To make the switch, Enbridge welding operators selected for qualification in the wire processes complete a one-week course that covers everything from equipment maintenance to welding metallurgy. By using equipment with a user-friendly interface, Enbridge is able to devote more time during the training program to the technique and metallurgy aspects of welding.
Operator training is critical for Enbridge to ensure that welding operators know the “why” behind the processes and potential issues in addition to knowing “what.” Proper education and training for welding operators is essential in the adoption of new processes and technologies, helping eliminate conversion risks before the new processes are used on the jobsite.
Reducing weld time by 40 percent
The switch from stick welding to advanced wire processes such as pulsed MIG and RMD resulted in significant productivity improvements for Enbridge — including a 40 percent reduction in weld time on those projects, thanks to higher-efficiency outputs and much greater travel speeds of the wire processes.
“With the addition of wire welding to our maintenance program we have seen our timelines become more flexible and our arc time decrease, while meeting our safety standards,” said Jason Johnson, Enbridge construction specialist. “This efficiency has allowed us to conduct more projects in a given year.”
Enbridge experienced these productivity gains without an impact on weld quality.
“With our robust weld quality program, we have not identified a significant difference in welding rework from traditional stick applications,” Johnson said. “This puts Enbridge’s wire feed welding program on par with traditional stick welding.”
As a North American leader in delivering energy for more than 65 years, Enbridge is adept at meeting ever-changing industry challenges. Changing pipeline materials, demanding project timelines and training of skilled welding operators are among the key challenges in the industry today.
A change in welding processes and investing in new technologies can help companies like Enbridge boost productivity and efficiency to meet these demands. Welding processes that are more productive and make it easier for welding operators to produce high-quality welds also help companies maximize the available labor pool, complete projects faster and stay within safety guidelines.
“Enbridge has always prided itself on seeking out new technologies to ensure quality and safety. Our welding program is no exception,” Johnson said. “With the world of pipeline materials rapidly changing, the need to use low hydrogen processes has expanded. Wire feed welding is a ready-made option.”
For Enbridge, the proof is in the results — with greatly improved productivity without sacrificing safety or quality on pipeline jobsites.