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Production • Processing • Handling


Paula Flanders looks at how plasma technology is being used on the Ruby Pipeline project in the US.


Paula Flanders observa cómo se utiliza la tecnología de plasma en el proyecto del gasoducto Ruby en EE. UU.


Paula Flanders untersucht, wie die Plasmatechnologie beim Ruby-Pipeline-Projekt in den USA eingesetzt wird.


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Fig. 1. A good quality plasma system is capable of making smooth cuts. The cut shown here was made by placing one of Hypertherm new Duramax torches on a mechanised pipe cutter.


Plasma systems save time and money in pipeline construction


t is early November and 6000 feet up in the Wasatch Mountains near Ogden, Utah, USA. Wet snow has turned the already rough dirt road to half-frozen mud. Although grey skies


are promising more snow, Kenny Glaze, member of Pipeliners Union Local 798, is on his way to repair a porous weld bead on Associated Pipe Line Spread 1B, part of the Ruby Pipeline project. Construction on the Ruby began


on July 31, 2010. Te approximately $3billion project includes laying roughly 680 miles of 42-inch natural gas transmission pipeline on a right-of-way through parts of four states: Wyoming, Utah, Nevada, and Oregon. By the time the pipeline is fully operational, it will carry 1.5billion cubic feet of natural gas per day and any delays beyond the target completion date will cost considerable time and money. A 20-year pipeline veteran, Glaze has


worked on numerous projects throughout the United States. Tis is the first one


where he has used plasma to repair welds though. “Before plasma, I had to use a grinder to access the repair area. Tat generally took 45 minutes or more of hand grinding. But now that I’m using a Powermax45 plasma system, I can gouge down to the repair area in a third of the time.” Hypertherm plasma systems, like the


Powermax unit Glaze used, can remove 6.2 pounds of metal per hour. Another time saving benefit is that the plasma leaves behind a weldable edge, and for Associated Pipe Line Contractors, hired to build sections of the line, every minute saved helps keep the project on its tight schedule and under budget. For the welders though, time saved is just the beginning.


Valve noise Fatigue and safety come into play as well. Te grinder is heavier and harder to hold than the plasma torch and grinding presents safety hazards, such as eye injuries, from flying debris. Tere are other options, but unfortunately, they aren’t much better. For instance, carbon arc gouging presents a problem because the carbon winds up puddling on the pipe and must then be ground off. On the other hand, the plasma system Glaze is using is highly portable, light weight and can cut 0.5-in mild steel with ease. Once the path for the pipeline has been cleared and prepared, sections of pipe ranging from 40 to 80 feet long and varying in diameter and coating thickness based on their specific location, are laid out along the path in a process called ‘stringing the pipe’. Te pipes are welded together, contoured, coated, inspected, and tested. Te inspection and testing phases may turn up defects in pipe welds that have to be repaired. For example, misalignment of the pipes can lead to


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