One of the primary uses for TIG is welding Stainless piping for process piping (chemical process, food process and power piping) did a lot of that years ago at Maxwell House coffee. It's also popular for aluminum fabrication such as Marine applications. For food process the piping is capped on the ends and purged with Argon to prevent any interior weld contamination. One of the attributes of TIG is that it uses no fluxes of any kind hence the weld are very clean..
I believe that the majority of my GenRight parts are TIG welded as they are aluminum. I could be wrong. But the welds look like the most beautiful stack of dimes you’ll ever see.