I'm starting a new thread specifically about the oxygen concentrator I bought over the weekend. The one I have has a brass barb, not a B fitting. I picked up some clear hose and a christmas tree adaptor needed to run this type, but I have a couple of questions.

How much clear hose should I use? The smallest amount possible? 50 feet? The hose I have is 7 feet.

And are the plastic christmas tree adaptors up to the task of brazing? This I might just have to find out for myself.

Here are a few pictures. Just a mock up, obviously the adaptor won't be fitted straight to the torch.
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