How fast do air tanks empty?

[magnum9987]

My friend and I have agreed that we will build a straffer. But, I am considering, instead of lugging around an air compressor in a truck, that I can get refillable High Pressure Air paintball tanks and use them to power it. I was thinking about a 20oz tank, but I need to know how fast the tank will go, or, how long on automatic fire the tank will last. I know that such tanks can safely handle 3000psi, so how long can I go on full auto?

[rp181]

That is not nearly enough information. Pressure of tank? Pressure into gun? Flow rate? Just use your flow rate and air capacity of the tank to calculate it.

[magnum9987]

sorry guys, I don't know too much information. It's a typical paintball tank, at 3000psi. All I really know. Thanks any way

[rp181]

There is no way to tell. You could have the tank empty through a needle sized orfice, or you could empty it instantly. It will be different whether your shooting BB's or marbles.

[starman]

Magnum, has your parents finally agreed to let you build a cannon?

[grock]

well, it really depends on what your shooting, but i run my airsoft one on 120 psi is a 24 oz CO2 tank, and i can get ~10k shots before it runs out. not so sure about HPA though. (for CO2) it also depends on how trigger happy you like to play, because if you shoot too much, your tank will cool down and lose pressure.

[magnum9987]

Yes I have in fact persuaded them that I can build a gun. I am working in conjunction with a friend but he thinks he is so much smarter than me, even though I taught him everything he knows about straffers. We want to build aq combat vehicle. He can get a jeep, and he gots the air compressor, which is a gasoline powered one. I want to keep the compressor and gun themselves seperate, so that the gun can be aimed in any direction freely, without hoses hampering it.
I am considering a 20oz HPA air tank (one used for paintball), or even a refuelable fire extinguisher, which can handle pressures of 5000psi, as opposed to the 3000psi of the paintball tank.

[TurboSuper]

And your air compressor can get past 3000 PSI, let alone 300?

[grock]

Turbo has a point. it doesn't really matter what tank you use, if your compressor cant get up to those pressures. most don't go up that high, in fact, the one at the metal shop i go to only goes up to about 150 psi, and that thing is the size of a small car. the best thing to do would be to hook the gun directly into the compressor, and just watch the hoses. also, you mentioned a 20OZ 3000 psi tank. most tanks that are measured in weight are CO2, not HPA. so a tank sold as 20OZ is most likely a Co2 one, not a HPA one. not to say that you couldn't get an HPA one, but there really isn't anything sold commonly that is sold as 20OZ AND 3000 psi. not that i can blame you, this took me forever to figure out. it was a real lightbulb moment for me.

[magnum9987]

I checked that the one I am interested in is a HPA tank, though thanks for the advice. Damn that limits me alot. Shit, the friend beats me

[TurboSuper]

Another problemo with compressed air is that it cannot be liquified. Single gases such as CO2 or nitrogen are stored in a liquid state, so you'll get consistently high pressure out of a small vessel.

[grock]

Another problemo with compressed air is that it cannot be liquified. Single gases such as CO2 or nitrogen are stored in a liquid state, so you'll get consistently high pressure out of a small vessel.

well, at least until they start cooling down. not sure about HPA, but there is such thing as liquid oxygen, they (or at least used to) fuel rockets with it. try putting THAT in a spudgun