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Improve productivity in pipe welding with welder/generator technologies

In any welding operation, finding ways to save time and get work done faster is critical to the bottom line. This can be especially true in oil and gas welding applications where contractors may be dealing with changing materials, increased pressure to meet shorter project timelines, and the need to get more welders trained and on the job quickly.

Pipe welding applications – whether it’s transmission pipe, process pipe or cross-country pipelines – demand extremely high weld quality. Weld defects cost time and money and have the potential to hold up the entire operation.

Welder/generators on the market offer several technologies to help address these challenges in field welding applications. From a change in the welding process to implementation of a new technology, these solutions can maximize productivity, quality and safety on the jobsite – and deliver the desired results.

Transmission pipeline welding requires a smooth, consistent arc that can handle variations in pipe fit-up.

Industry trends

Several factors are driving changes in oil and gas welding applications. As technology advances, the materials being used for pipe applications are changing.

These metals often have different compositions or properties that can make them more difficult to weld. Successfully producing high-quality welds with these materials may require a change to the welding process or technique. For example, with some metals, it may not be possible to use stick welding, and a different welding process or filler metal is needed to achieve the proper weldability and mechanical properties in an advanced chemistry, high-strength steel pipe.

In addition, demand for welders is growing as the oil and gas industry rebounds. With more projects to take on, many contractors want to improve the productivity of their existing workforce and decrease training time for new welders. The faster workers can be trained, the more productive the operation.

Advanced welding

While stick welding remains prevalent on many jobsites, more pipe welding contractors are converting to wire processes in the field. In the right applications, wire welding processes provide significant benefits for productivity without sacrificing weld quality.

Advanced wire processes – such as pulsed MIG and regulated metal deposition (RMD), a patented modified short-circuit MIG process from Miller – offer even greater advantages for productivity. They provide consistent weld quality and travel speeds that are three to four times those of stick welding.

These advanced processes are commonly used in fabrication shops and are now available in welder/generators designed to meet the demands of jobsite and field applications. The ArcReach Smart Feeder from Miller includes pulsed MIG and RMD processes, and the feeder can be paired with several welder/generator options. This broadens the offerings in terms of where advanced wire processes can be used.

Dynamic Dig technology available on Miller’s Big Blue 400 PipePro welder/generators offers improved puddle control, more flexibility in the arc and the ability to complete high-quality welds at faster speeds.

A modified short-circuit MIG welding process such as RMD offers easy weld pool control because of greater forgiveness to variations in stickout and gun angle. This helps reduce operator training time while delivering quality arc performance that helps boost productivity.

Using this process also produces less spatter and allows for the elimination of backing gas – factors that help save time and money.

Advanced wire processes also tend to require less heat input, which reduces the chance for slag inclusions, undercut or suck-back in the weld – resulting in less time spent on rework.

The specific pipe chemistry may also dictate the welding process that is used. The harder the material, the more susceptible it could be to weld cracking. Choosing a low-hydrogen welding wire, such as those in the Hobart Megafil seamless wire series, reduces the risk of weld cracking by having flux-cored and metal-cored wires with diffusible hydrogen levels as low as an H2 rating, as defined by the American Welding Society.

Using wire processes on the jobsite may require some accommodations, such as setting up a tent or hut over the pipe to keep the wind from blowing away the shielding gas. But, the greater efficiencies and savings offered by these processes can deliver a quick return on investment.

Transmission pipeline welding

Not all pipe welding applications are well suited for a transition to wire welding processes. There are also technologies available to help improve quality and productivity for stick welding in the field.

For pipeline welders, the most critical deliverables are producing high-quality stick welds and completing the job quickly. The more weld metal that can be put into each pass, the faster the welder can move on to the next weld joint – and eventually the next job.

New Dynamic DIG technology from Miller addresses the specific challenges of transmission pipeline welding by delivering a smoother, more consistent stick welding arc that can be tailored to match the application, material, variations in pipe fit-up and welder technique. This results in improved puddle control, more flexibility in the arc and the ability to complete high-quality welds at faster speeds.

One common challenge in pipeline welding is inconsistent fit-up, which can result in extremely tight or mismatched gaps when laying in the root pass. As the pipe is welded from top to bottom, the joint may go from a proper root gap to very little or no root gap, requiring the welder to make changes in technique to accommodate for this variance. This requires a machine with enough drive to allow welders to push the rod in, using more force on the electrode, all while keeping the arc lit and getting the necessary penetration with a tight gap fit-up.

When power sources don’t have enough drive to provide this ability, the arc can be snuffed out during attempts to penetrate tight gaps. Dynamic DIG technology provides the necessary drive and arc adaptability. It’s a software-based waveform technology that automatically adjusts the amount of current required to clear a short.

As a result, the arc is more reactive to how the welder is using their electrode, providing greater arc and puddle control. If a lot of drive is required for the root pass, the welder can tailor the arc to deliver plenty of penetration. When the welder needs to soften the arc and dry up the puddle to make a wider hot pass or cap pass, the technology can provide those capabilities, as well.

The arc characteristics can be optimized for the fill and cap passes to lay down a lot of weld metal, so welds can be completed faster. The end result is a greater ability to fine tune the arc, so welders can easily adjust it based on what they’re seeing with each pass.

More jobsite control

The ability to make weld parameter adjustments remotely is another technology designed to make welding on the jobsite more efficient.

Making do with less-than-optimal weld settings and spending time on non-value-added activities, such as rework or walking to the power source multiple times a day to make parameter changes, can cost thousands of dollars per year in a pipe welding operation.

ArcReach technology, which provides complete control of welding parameters at the weld joint without a control cord, is now available on nearly all Trailblazer and Big Blue welder/generators. The technology eliminates time-consuming trips back and forth to the power source to make changes, which also reduces the risk of operator injury on the jobsite.

Hobart’s low-hydrogen Megafil seamless wire series lowers the risk of weld cracking by including flux-cored and metal-cored wires with low diffusible hydrogen levels.

Operators can make changes with the push of a button at the wire feeder or on a remote. This results in less wasted time and more arc-on time, helping welders complete more welds and achieve higher overall productivity. It also offers benefits for weld quality because welders can easily set the exact parameters they need without leaving the weld joint.

Pipe welding applications require high weld quality – often on demanding project timelines. A welder/generator with the right technologies can help contractors complete quality work while improving productivity and efficiency.

Welding technologies that make it easier to produce high-quality welds in the field can save time and money in rework and welder training. Organizations may want to address key industry challenges or ensure that jobs are completed on time and on budget. Consider the potential productivity gains offered by advanced welding processes and new technologies and procedures.

Hobart

Miller Electric Mfg. LLC

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