Physics and a Nitro Tank

[Mr.Danger]

When my air guy fills HPA tanks, he fills them quick enough to heat the tank consideribly. When he handed me the tank one time, it was full and almost too hot to handle. True to the laws of physics of course, once the tank cooled down, the pressure within the tank also dropped. Then I remembered my chemistry class. According to (insert name of law) as the pressure within a closed container increases, so does the temperature. Likewise, when the temperature of the container increases, so does the pressure. This lead me to pose this question: Would raising the temperature, and thus the pressure inside, of a partially filled HPA tank offer you more shots than one kept at a cooler temperature ?

[SlartyBartFast]

When my air guy fills HPA tanks, he fills them quick enough to heat the tank consideribly. When he handed me the tank one time, it was full and almost too hot to handle. True to the laws of physics of course, once the tank cooled down, the pressure within the tank also dropped. Then I remembered my chemistry class. According to (insert name of law) as the pressure within a closed container increases, so does the pressure. Likewise, when the temperature of the container increases, so does the pressure. This lead me to pose this question: Would raising the temperature, and thus the pressure inside, of a partially filled HPA tank offer you more shots than one kept at a cooler temperature ?

If it was too hot to handle, the tank may now be dangerous.
Yes, heating the tank might get you more pressure. But see previous.

[ScatterPlot]

as the pressure within a closed container increases, so does the pressure.

E-gad, man, that's genious!

[Mr.Danger]

Sorry, you know what I meant.
Anyway, "too hot to handle" may be a bit of an exaggeration, but it was warm enough to make my hands sweat. So, before a tournament would it be worth while to leave a tank in the car to "warm up", or would it be doing more harm than good to the tank and/or marker for the sake of a few extra shots?

[ProX9]

when air is hotter it is also less dense, not in the case of a closed container because it cant expand but when it goes into the gun im pretty sure it would take a larger volume of hot air to do the same thing as room temp air.

[SlartyBartFast]

Sorry, you know what I meant.
Anyway, "too hot to handle" may be a bit of an exaggeration, but it was warm enough to make my hands sweat. So, before a tournament would it be worth while to leave a tank in the car to "warm up", or would it be doing more harm than good to the tank and/or marker for the sake of a few extra shots?

Before a tournament?

How about just getting a decent fill while you have the time.

And you can't tell me you're emptying a tank every game.

Read the article I linked in the thread about wet SCUBA fills. I'm too lazy to search right now.

[ScatterPlot]

Well I can empty a tank a game, especially when it's a 45/45 on an automag not getting full fills

[SlartyBartFast]

Well I can empty a tank a game, especially when it's a 45/45 on an automag not getting full fills

Well, get a bigger tank, or get better fills.

[nicad]

Boyle's law is what your looking for.
Volume, pressure, and temperature are all directly related.
Change one, and one or both of the others will change.

If you Google it there are countless equations and even calculators for it..

out!

[ScatterPlot]

PV/T=PV/T

There's no subscripts in this, so I'll jst tell you- the ones on each side are for the 2 different "times"- say the left was original, then you change something and find out on the right.

[Papabyrd]

PV=mRT

or PV=nRT

or P=pRT (where p is density-rho)

[latches109]

http://www.carltech.com/new-composite/pbfastfill.html

[SlartyBartFast]

http://www.carltech.com/new-composite/pbfastfill.html

It's about time that cylinders had an indicator that changed colour at the 'danger' temperature embedded in the epoxy.

Until someone gets killed at a self-service fill station, I doubt anything will be done to regulate the filling of paintball cylinders.....

[latches109]

true.

[St Elmo's Fire]

I'm not an advocate of messing with the pressure in a tank like this, and I would not recommend this. But, if as your tank began to empty, you started to heat your tank up a bit, I expect that it would increase the number of shots you had available. You could do this before-hand as well, but I don't suggest you fill a tank to it's limit, and then pressurize it further.

But, yes. Further heating of the tank would build up pressure, but the only time I can see this being feasibly used is in the middle of a match when you're starting to run low. I can't imagine a whole lot of paintballers are emptying 45/45s in a single match though, so it's not an important factor. There is no real advantage to heating the tank beforehand, you might as well have overfilled the tank.

And for those who do empty 45/45s in a single game, you might consider a larger tank. Heating your tank wouldn't buy you that many extra shots, considering that the equations need to be done in Kelvin. For a person in an 80-degree field, to heat their tank to dangerous amounts of 140-degrees...

300 Kelvin -> 333 Kelvin.

You'd get a little more than 10% more shots than you have left. Doing this to a tank though could cause damage to the tank, which endangers your life. Furthermore, if the tank were full and not at least partways empty, you run the risk of over-pressurizing the tank.