Now here is a question that I can answer.
Oxy concentrators are really easy to use. You will only need one of
them to run your Smith. I am assuming that you have a "standard"
unit that will output 5 liters/minute which will give you around
2-4psi (give or take I am not a scientist or expert here so I am
sure that the psi conversion from lpm is wrong, but you won't blow
I used to run my glass torch on a single concentrator and switch
over the hoses to my Hoke when I was soldering. I can't imagine that
you would need to use both concentrators chained together for your
purposes - a glass person would do that if they were going to work
hard (pyrex) glass but I honestly don't think that you need to go
that far. I don't use one anymore since oxy is so cheap here in
Thailand that it seems almost insane to rent or purchase a
concentrator when I pay $2.50 for a full sized tank delivered.
You will not be using a regulator for the oxy side, so you just
attach the hose to the little nozzle with a ring clamp. And you use
the level knob for the concentrator to then regulate the oxy.
If you do want to chain them together then there are some good
instructions here: http://www.suncoastbeads.com/
The only other thing I can think to tell you is to watch the purity
light. This is more important when you are working with glass - I am
not sure what the effect is when you are working metals - Your
concentrators most likely run around 95% oxy purity and the light
will go yellow when this starts to degrade. Again - I'm not sure if
this is AS important for metal.
If you need any other help feel free to email me off-list.
Hope this helps