how do you get hot fills from air bank?

[jrockosaurus]

My lds consistently underfills my tanks by several hundred pounds and blames it on hot fills. The tank usually is warm when they give it back to me but not so that it would cool to the level that I get it at. I got tired of getting bad fills and told the guy that he was full of bs and that you can't get hot fills from a bank. The heating of the air is caused by the initial compression. You actually should be getting cooling since you are taking a fixed volume of air and putting it into a larger space. So unless the compressor kicks on every time I get a fill, then he's just screwing me out of some air. Who's right here?

 

[JeffG]

Who's right here?

Not you.

 

[jrockosaurus]

Not you.

very informative, thanks

 

[JeffG]

very informative, thanks

You're welcome.

 

[diveprof]

Often it is a combination of a "fast fill" (usually the case which generates heat), or to a lesser degree, not placing your tank in a cold water environment when filling to reduce heat. There is no acceptable excuse for a shop not filling your tank to the approved psi.

 

[H2Andy]

you can't get hot fills from a bank

you can

it helps if you put the tank in a water tub and tell the guy to slow the fill down,
but it still gets hot.

ideally, he'd agree to "over-fill it" by 200 psi or so, and that will also help when
the tank cools down

 

[jrockosaurus]

you can

it helps if you put the tank in a water tub and tell the guy to slow the fill down,
but it still gets hot.

ideally, he'd agree to "over-fill it" by 200 psi or so, and that will also help when
the tank cools down

why does it get hot though? thanks for the responses!

 

[H2Andy]

well... as far as i know (and i know very little), it's the friction of putting all that
air into the cylinder

 

[Boogie711]

I hope you plan to apologize to your dive shop.

 

[JeffG]

well... as far as i know (and i know very little), it's the friction of putting all that
air into the cylinder

Yes, the little air molecules are rubbing their hands in anticipation of being squished against each other.