TIG Welding Stainless Steel tubing with full penetration requires a purge in order to prevent severe oxidation on the inside.
There are some applications where purging the inside is an absolute must...especially in food service applications.
The manifold in the video is not required to be done to food service requirements since it strictly holds liquid nitrogen.
But that's no reason to skip the purge.
I first learned about tig brazing with silicon bronze while I was moonlighting at a sheet metal fab shop.
Owner brought me a hydraulic tube from the forklift that had sprung a leak and was worn paper thin and also handed me a piece of silicon bronze filler rod. I show a mockup of that repair in ...
Doesnt do much good to have 280 amps if your tig torch is only rated at 150 amps.
So I hooked up a water cooler and water cooled tig torch and brought you along in case you need to do the same
Welding is when you melt the base metal.
Brazing is above 840F but not hot enough to melt the base metal.
Tig brazing with silicon bronze is a very useful thing to know