Air fill question:

[eieio_24]

I was wanting to see some opinions on hot fills vs. cold fills. I've always preferred having my tanks filled submerged and cool vs. a hot fill, as some shops do. One, I usually always leave with more air, and it also seems that it would be better for the tank. Anyone have an opinion or factual data on this ?

 

[MichaelBaranows]

I try to always give a cool fill. But at the lake when I am filling tanks slow some people seem to get in a hurry and want their tank fill in a hurry.

 

[texdiveguy]

Slow cool fills always!....NO water tank baths for me. OMO

 

[willembad]

Why no water baths?

 

[texdiveguy]

Why no water baths?

There IS always a chance of water entering the system/rare but is a risk,,has been shown that the amount of heat dissipated with the water tank bath is minimal, and if you fill at a slow rate you will 99% of the time get the target PSI fill you are looking for. Not to mention they are messy both for the shop/fill station. Again these are just a few reasons. And you still can get a hot fill even if the tank is filled in a water tube. I don't fill in a water bath.....and in all my years of diving I have only allowed it one time on a single. JMO

 

[FIXXERVI6]

I favor water bath

 

[MichaelBaranows]

One problem I see with a water bath is that if you are filling alot of tank the water bath will end up getting hot over time.

 

[vintagediver]

Quick fill, dry.

Less time for the metal of the tank to absorb the energy from the air.
The metal of the tank dissapates heat energy within the air.
Target is reached, less total heat, and less loss of pressure.

 

[Scuba.com]

Filling dry with a fill rate of 300 to 500psi per minute as recommended by Professional Cylinder Inspectors: Wet Fills

 

[FIXXERVI6]

People can show me all the numbers charts and links they want

But I notice when:

I fill the cylinder in the bed of my truck to 3600 then add for cool down the fill comes up short

vs

fill the cylinder in a water bath at the same rate then add a touch for going over and the fill comes out right

good enough for me