fits of its new approach were evident. When using the standard SMAW process on previous 24-in. outside diameter pipeline projects, it was expected that each weld joint would require three worker hours to complete. This included welding of the root pass, two fill passes, and the cap pass. While the percentage of unacceptable welds was very low, practically zero, the appearances of the welds were always different from welder to welder. This visual variety was less than appealing and left opportunities for questions during visual inspection. On a recent 24-in. project, the Pipecat tractor with the wire feeder and mechanized welding system was employed — Fig. 6. Senior Crew Lead Lance White performed all of the welds on the project. The welding of the root pass was still performed with the SMAW process, but both fill passes and the cap pass were performed with the mechanized tractor and FCAW-G. Understanding that the root pass was performed with SMAW, just as in the standard method, and would therefore take the same amount of time, it was estimated that the speed for the remainder of the welding was increased by approximately 300%. Almost all of the welds appeared nearly identical. The concern about cosmetic appearance during inspection was eliminated. G. L. “Woody” Garvey, CWC director special projects, PM/CM services, pointed out that many newer welders know what they should see as the weld is going in but they often do not yet have the dexterity to make it happen. With the mechanized system, these newer welders can be successful and productive much quicker than when they were expected to perform the motion by hand. The hands that are better on the root pass can be employed there, while the less experienced hands can perform the fill and cap welds. The Plan Moving Forward Prather and his work force explored options and came up with a system that improved their productivity; all with relatively low investment but lots of ingenuity and inventiveness. While the change was not without challenges, the results were outstanding. As the company is presented with more short-run opportunities, the plan is to add additional welding equipment and mechanized systems. W ORK SM MART NOVEMBER 2016 / WELDING JOURNAL 49 WJ Fig. 6 — Mechanized welding under the tent. FRANK J. NELSON (jnelson@weld.com) is manager, technical sales and special systems, Bug-O Systems, Inc., Canonsburg, Pa., bugo.com. WILLIAM H. PRATHER (cwcontracting1@ msn.com) is owner, president and director of construction, Clearwater Contracting, LLC, Nampa, Idaho. cw-contracting.com. Model 200 Positioner 3 models av , . Mode Rot from el 1200 Pipemate tates pipe and tube 1 ½” to 17” diameter, For info, go to aws.org/adindex
Welding Journal | November 2016
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