No problem.
I just posted about that above, before I saw your response. 40-50 litres is a lot, that's gonna be a big, heavy cylinder. Get a 5 or preferably a 10 litre. But obviously a 40-50 litre is fine if you can't get smaller and can transport it ok.
It can be confusing alright. They advertise the cylinders as litres in water volume in some countries, e.g. 5 litre, 10litre, 40 litre etc. To get the rough amount of compressed gas in litres, you multiply the water volume by the bar pressure. So a 5 litre cylinder at 200 bar pressure gives roughly 1000 litres of compressed gas. Confusing, I know!
That purity is fine. If you wanna be sure, you can test the purity yourself using an oxygen detector(but most people probably don't bother testing) Here's what
@GasMonkey used:
View attachment 125903
They probably won't ask questions. Just say you or your partner are using nitrogen to make home brewed beer, if they do. Or for your uncle/brother/ father who's a welder.
The tubing goes on the outside of the regulator connection, on a thing called a hose barb that usually comes with the regulator. Here's a photo of
@FailerQt.'s tube on the regulator hose barb, from the previous page on this thread.
View attachment 125904
You just need to get small mini hose clamps to secure the tubing (see their posts on the previous page).
Hose clamp:
View attachment 125909
I just noticed today that the PPH recommends using tubing with soft connectors at each end, because it makes a thicker connection for any hose clamp used:
View attachment 125907
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