Prior Situation

A regenerative braking system engineering firm and fabricator, located in northern Colorado, came to General Air in search of a more cost effective solution for fabricating their cylindrical high and low pressure hydraulic fluid accumulators. Switching to metal-cored wire and a joint design change will help them with their problem.

Fabrication processes employed at the time consisted of an open root TIG weld followed by an .035 hard wire short circuit cap pass on 12g wall butt joint. The multi-process, multi-pass operation is time consuming. Additionally, the rubber bladder in the cylinders rubs against the root weld and wears, sometimes failing. These two problems needed a solution and we found them.

PE Solution

First, we asked the end-user to refurbish an old turntable they had sitting in the corner. Next, we loaded 045 metal-cored wire into a Lincoln C300, hooked up a 90Ar/10CO2 cylinder and fixed the torch at 10 o’clock. Because full pen welds were not required, we closed the gap and tacked the circumferential butt. This joint design, unlike the open root design, would not leave a weld to potentially scar and burst the bladder.

Through procedural trial and error, we eventually achieved nearly perfect, repeatable single pass welds at a surface travel speed of 61 IPM. Even more, zero spatter was produced, a stark contrast to the short circuit cap pass.

Success Highlights: $12.30 Per Foot of Weld

• 96% reduction in cost per ft of weld
• 454% increase in surface travel speed
• Consolidation of 2 passes/processes to 1
• Elimination of internal bladder damage