Greetings - I teach at a dive shop in San Diego. We only do air fills (no Nitrox or Tri-mix). Recently a couple of Tec Divers came into the shop with these massive doubles filled with Tri-mix, and wanted us to top them off with air.
OK. The resulting gas would be another mixture which would ultimately need to be analyzed; but it's no problem at all.
Sure it's safe. Why wouldn't it be? They just need to analyze the resulting gas.The question came up on our side about liability, whether it's safe, etc.
What problems can you run into with an air fill? Filling a tank with pure Oxygen - that could have issues, but air?
I'm sure you could have them sign some kind of waiver, but I'm curious what other's thoughts might be on this in terms of risks or liabilities? Do other shops do this?
None that I get fills at...
Topping with air is doing an air fill. I am not getting a trimix fill, nor am I getting a nitrox fill... I come in to the shop asking for an air fill, and that's what I want. I can analyze the gas myself, and calculate my subsequent dive based on that mix.