Regulator makes Cylinder hot ?!!

[eukanuba]

I have a 3000psi, 88ci AirAmerica cylinder and reg..

The reg is a Melee.. preset output at 800psi..

Now, I fill to under 3k psi using my scuba cylinder... and normally this cylinder does not get hot.. it stays quite cool...

But last week I got a new ( note: used, but new for me )
AirAmerica Apocalypse Reg - with adjustable output..

When I fill my cylinder with this reg on - my cylinder gets quite warm, almost hot.. this has never happened before - I fill slowly, not rushing it or anything.. can anyone suggest a solution ? or is this just normal....

( I have read the manual a dozen times, and rebuilt the reg to make sure its not got any dirt or contaminants inside.. its all clear !! )

- Euk.

[Dannefaerd]

Boyles Law.

When you're changing the pressure of a cylinder one of two things has to change to keep things balanced - either the volume or the temperature. Since the volume is fixed ... the temperature has to increase.

This time you're just noticing it - that's all.

Marty

[Camo]

Very clever dannedaerd, Pravo!! :)

[eukanuba]

Boyles Law.

When you're changing the pressure of a cylinder one of two things has to change to keep things balanced - either the volume or the temperature. Since the volume is fixed ... the temperature has to increase.

This time you're just noticing it - that's all.

Marty

Simply stated, Boyle's Law indicates that for a fixed amount of gas (fixed number of moles) at a fixed temperature, the pressure and the volume are inversely proportional.

pV = constant or p1V1 = p2V2

But, when I do exactly the same experiment using using both regs.. I notice no difference in cylinder temp when filling using the smaller reg..

Maybe the extra surface area from the larger reg ( and its huge, if you've ever seen them.. ) could be causing the heating as the melee is 1/4 the size of the all stainless steel adjustable apocalypse reg..
Maybe the pressure travelling the extra distance is causing the heating as it travels through the stainless steel..

The melee looks like a sugar cube next to the huge apoc reg.. but nonetheless - it is really weird.. esp when you do it, discharge the cylinder - then try it later, and its no where near as hot - not even warm !!!!

Maybe I should put my scuba cylinder in the fridge next to my beer kegs and cold charge my hpa fibre wrap cylinder.. just a thought..

Anyone got any idea's ? I am stumped....

- Euk.

[GAV WA]

It's not a big problem so long as like you said you fill at a nice steady rate and not too fast as then it'll really get hot. It is quite common. Probably the apocalypse has smaller passages for the air to go through and this is why it is heating the air more than the Melee. Those presets do fill quite fast and easily as they have quite an unrestricted passage and therefore usually heat up less.

[Jamie_Cracker]

i would have to pretty much agree with Gav,the reg most probably has smaller air passages and if it does it will heat up a bit more.I have found the same things with different filling adapters etc at work
oh yeah are we gonna have a gas law quiz later???? :evil :evil

[Mary101]

uh I found that my legion air preset from mac dev gets warm as does the adjustable conquests from the same company, don't know about any body else but since both are cylinders and both expand and contract, I would imagine it would be the same for every tank

[ticker]

maybe the the bigger reg isn't a good heat sink so there for puts mor temp into the charge air.keeping the cyclinder in the fridge isn't b bad idea as when the air is cold it is denser and you can fit more air into the same space