Why Purge Welding Matters | Preventing Corrosion in Stainless Steel Pipe

What happens inside a weld is just as important as what you see on the outside. In this video, one of Astro's experienced welders, Phil, demonstrates the process of purge welding a stainless steel pipe for a water system. Phil explains how pumping argon through the pipe displaces oxygen before welding to prevent oxidation, sugaring, and porosity on the inside of the joint. Phil also walks through his process for verifying a complete purge, performing a full-penetration root pass, recognizing the weld keyhole, applying a cover pass, and inspecting the finished weld to ensure complete penetration and a clean internal weld profile. Proper purge welding helps preserve the corrosion resistance of stainless steel, creating welds that are as strong and clean on the inside as they are on the outside. For critical piping systems, this extra step can help ensure decades of reliable performance. In this video you'll learn: (0:00-0:51) What purge welding is and why it's used (0:52-1:13) Trick to ensure pipe is filled with argon (1:14- 2:33) Welding the root and cover pass verified using internal inspection (2:34-3:12) Keyhole explanation and final product reveal #PurgeWelding #TIGWelding #StainlessSteel #PipeWelding #WeldingTips #Manufacturing #MetalFabrication #IndustrialFabrication #WaterSystems #WeldingTechnology