air fills

[scubafreek864]

The above wouldn't make any sense to me.  If the tank is submerged in water to keep it cool, it would be also keeping the metal from the heat expansion that would come from hot/dry fills.  Hot metal expands, while cool metal does not.  The way I see it, my tanks would last a lot longer by doing wet fills, because the tanks are not expanding as much every time I get them filled.

[aknelsonone]

I guess this has some merit. In addition all those shops offer some little services like VIP etc.
This is part of their business.
I was running for years to a shop 40 miles away to get Nitrox or O2. This changed after I was equipped to
blend. Noweaday I look foreward to see a shop for a air fill. Dispite I dive on a regular base.
I guess some folks just do not put a price tag on running around to get air a fill or crab about a few bucks..

Andy

[arcFlash]

WHAT, WHAT did I do? I just gave a local business model idea.

[Seal]

Cylinders should not be hot filled, the proper fill rate  is 300 to 600 psi per min.  If the shop is using a fast fill the cylinder will not get rid of the heat as fast as the cylinder is being filled. The only way it would work is to pre cool the cylinder before it is hooked up the the whip.  Just ask the shop employee in FL how well that works doing a fast fill after that.  Oh by the way he has no comment as he did not live. The dive center should be over filling at 5 psi for every degree of air temp. over 70 degrees and if filling at the proper rate it will be a good fill.  Now if the air temp. is below 70 degrees the FSO should be doing the opposite. If an 80 cu ft cylinder would blow up the 1.2 million pounds of energy, the water in the tank would have no impact other than making a mist.  I had a burst disk blow on a 72 cylinder in a 55 gallon tank when we used to fill in water and there was not 2 gallons of water left in the tank and that was just a burst disk.  Yes fast fills do affect how long a cylinder will last especially AL cylinders.  Overfilling is just as bad as this will stress the cylinder and shorten its life and I would not want to be the one filling it.  I teach Hazmat training for high pressure cylinders and it is scary when I hear how cylinders from paint ball on up to scuba cylinders are being handled. 

[Adam6521]

I know its a drive, and only Thursdays but Owatonna dive club charges $2 a fill.  Always lookin for members never have to many

[acharpenter]

Wow!!!!!!!!!!!!!!!!!!!!