I'd assume a little air may well get in as there's air in the nozzle I suppose. Maybe over time it effects it. Dunno. I've also had issues with them no longer working right. Hard to say what the problem was, and I'm not going to claim it was the air.

Anyone on why you'd turn the gas to the lowest setting? Seems a waste of time and effort despite what little you'd put into it.

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Quote Originally Posted by FireTom View Post
I don't purge mine but I do put them in the freezer for about 20 minutes before I fill them. Something about it lowers the pressure in the lighter to allow for a better fill. The only thing I can think with closing the gas valve is that maybe there will be less chance of fluid leaking by the valve?
Hmmmm... Being an A/C guy the temperature certainly effects the pressures. I've had to do that to a container to accept freon. After it begins to get near capacity it slows down to a trickle so cooling it down will speed it up.