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Understanding that I am not learned in the art of tank inspection, I am going to ask a dumb question. What pressure (or lack thereof) constitutes an empty tank? Is there a standard for this?
crack the valve and it expels air...
A proper fill includes cracking the valve to expel any water in the valve (and on the face) as well as cracking the whip to expel any water that may be in the whip end. These tiny droplets of water likely result in 90% of water damage in cylinders, but you’ll only see it in the very best trained shops and fill stations.Ok, going under that definition is it normal to crack the valve before you have put a fill whip on it? I haven't ever seen it done but maybe that is because it wasn't a freshly hydro'd tank.
At this side of the world there are many.
View attachment 549075
this is a bigger one with 200 and 300 bar fills and air and nitrox. There are a lot of them that only offer 200bar air.
for nitrox you do need coins from a dive shop, they check your C-card. Air is possible with money.
A proper fill includes cracking the valve to expel any water in the valve (and on the face) as well as cracking the whip to expel any water that may be in the whip end. These tiny droplets of water likely result in 90% of water damage in cylinders, but you’ll only see it in the very best trained shops and fill stations.
Additionally, it takes tank pressure to seat the o-ring between the yoke and valve face.