All you need is a nitrogen bottle, and a regulator that will allow for up to 75-80 psi output. Don't worry about tapping into the lines on the plasma, leave those alone, just hook up the bottle like you normally would shop air.
Nitrogen has no moisture or oils in it, so your tips will supposedly last longer. From what I understand, nitrogen is generally used mainly for High-definition plasmas, and really not needed on smaller mainstream plasma cutters.
I don't know how much you would pay for a bottle, but I pay about 25 bucks for a 220 bottle here. It might be worth it to rent a bottle and try. If it doesn't make a dramatic improvement, take the bottle and regulator back.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
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