Anyone know anything about this dinosaur? (TIG)

Cope said
What's the benefit of running the water? Is it needed?

Thanks again.

The water is used to cool the TIG torch. Water cooled torches are smaller, have higher amperage ratings for a given size, and use less shielding gas. Even the lower amperage air cooled torches can get pretty hot pretty fast so they're not great for long operations. And as topiscuda pointed out if you have a water cooled torch you can't use it without water, air cooled torches are a different design. There's a decent discussion over at the miller welds forum Water Cooled Torch VS. Air cooled - Miller Welding Discussion Forums

Also, that forum has some pretty experienced folks, some with pretty good knowledge of the vintage machines. Might be helpful to check it out.

I have a water cooled torch on mine. On the old rigs like the 320 AB/P and that Birdsell the water coolers were a separate part, basically just a box with a pump and reservoir that was routed through a couple of solenoids attached to the welder for flow control. Keep in mind these welders had multiple functions, they can also be used as stick and arc welders. Both of those operations take less equipment than TIG. To use that machine to TIG you'd want a water cooled torch, the water cooler set up, and a remote foot pedal. That stuff has to be matched to the welder too, the old foot pedal leads and plugs are different from the modern ones. Same with the torches. It can all be adapted, but it's a lot easier to get a machine that has all of its accessories with it.