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12 gram CO2 questionsHow much pressure is contained within a 12 gram c02 canister?
What is the internal volume of a 12 gram co2 canister? Is there an adapter that can conect one of these canisters to a 1/8" npt or any other npt?
http://www.palmerpursuit.com/cart/index.php?cPath=40&main_page=index
I think some of those would work
more specifically, one of these Pressure depends on temperature and the amount left in the canister. Keep in mind that CO2 cools a lot as it expands (reducing pressure)
12 gram CO2 released into a chamber size:
5 Cubic inches 840 psi 6 Cubic inches 700 psi 7 Cubic inches 600 psi 8 Cubic inches 525 psi 9 Cubic inches 466.666667 psi 10 Cubic inches 420 psi 11 Cubic inches 381.818182 psi 12 Cubic inches 350 psi 13 Cubic inches 323.076923 psi 14 Cubic inches 300 psi 15 Cubic inches 280 psi 16 Cubic inches 262.5 psi 17 Cubic inches 247.058824 psi 18 Cubic inches 233.333333 psi 19 Cubic inches 221.052632 psi 20 Cubic inches 210 psi 21 Cubic inches 200 psi 22 Cubic inches 190.909091 psi 23 Cubic inches 182.608696 psi 24 Cubic inches 175 psi 25 Cubic inches 168 psi 26 Cubic inches 161.538462 psi 27 Cubic inches 155.555556 psi 28 Cubic inches 150 psi 29 Cubic inches 144.827586 psi 30 Cubic inches 140 psi 31 Cubic inches 135.483871 psi 32 Cubic inches 131.25 psi 33 Cubic inches 127.272727 psi 34 Cubic inches 123.529412 psi 35 Cubic inches 120 psi 36 Cubic inches 116.666667 psi 37 Cubic inches 113.513514 psi 38 Cubic inches 110.526316 psi 39 Cubic inches 107.692308 psi 40 Cubic inches 105 psi 41 Cubic inches 102.439024 psi 42 Cubic inches 100 psi 43 Cubic inches 97.6744186 psi 44 Cubic inches 95.4545455 psi 45 Cubic inches 93.3333333 psi 46 Cubic inches 91.3043478 psi 47 Cubic inches 89.3617021 psi 48 Cubic inches 87.5 psi 49 Cubic inches 85.7142857 psi 50 Cubic inches 84 psi ///ed///
Thank You this is exactly what I was going to calculate if I knew the internal volume and pressure. Thanks for do all of this work for me.
Those are rough figures at an average temperature, be careful using those, if its cold pressure can drop, just as it can increase if it gets hot.
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"George Will
Re: 12 gram CO2 questions
You really don't need to know either the pressure or the volume inside the cartridge. You can get a "close enough" answer by assuming the volume of the cartridge is small compared to the chamber, and hence can be ignored. The cartridge contains 12g of CO2. That's 12/44=0.273 mole of CO2. At STP (0C, ~1 ATM pressure) that 0.273 mole occupies (0.273mol)(22.4L/mol)=6.1 liters. From that you can get the pressure at other volumes (and temperatures) accurately enough for your purposes. If you want more accurate numbers, particular if you want to deal with temperature affects correctly, it's easiest to just use GasEq to do the math.
Re: 12 gram CO2 questions
instead of doing all the math by yourself.. just use a computer program that I created for this:
http://www.spudfiles.com/forums/co2fil ... 18709.html
Re: 12 gram CO2 questionsMay i ask what you need a threaded c02 cartridge for? They sell threaded ones but i am not sure if they are npt. Imo 12 grams are a waste of money considering the small amount of carbon dioxide you are actually getting. Not much use in spudding as far as large bore is concerned
Yeah, it's that important.
I would like tt have a very compact low volume source of air for powering a small air cannonj( 1/2" bore >24" long)
Where can I buy threaded cartridges. I looked at walmart and the only ones that they had where smooth necked. Is there and adapter that can hold these? Edit: I live in Ohio near Urbana.
At 1/2" bore that is 24" long, with a 12g co2 cartridge, you are looking at around 843.96822 PSI. DONT make it out of PVC or ABS.
Re: 12 gram CO2 questions
I called a manufacturer a couple of years ago. They told me it was right at 1000PSI. If your barrel size is really 24" and 1/2" dia, you would need a much larger opening than what a 12 gram cartridge will give you to get any kind of decent velocity and you'll have to push it all out that large barrel (for a 12gr).
Last edited by kenbo0422 on Mon Dec 21, 2009 1:58 pm, edited 1 time in total.
bike stores have threaded ones. they also make them for 12 grams to screw into paintball asa"s wich go to 1/8 npt
There is obviously a serious misunderstaning here. The barrel would be 1/2 by 24, I would have a camber of some sort that would hold the co2 pressure. The chamber would be conected to a valve that conects to the barrel and though some method the 12 gram would presurize the chamber.
A half inch barrel at 24 inches long will be 4.71 cu. in. It will take about 0.139 grams of CO2 to fill that volume at STP, which will give you about 86 shots, assuming you'll be putting just enough CO2 into the barrel to push out the projectile. If you want more velocity, then of course, your CO2 usage will go up to have pressure remaining in the barrel just as the projectile leaves. I'm guessing you might get about 2030 shots, depending on your projectile weight and desired speed.
There are some decent articles and such on Doomlabs and Warpig about CO2 that may be of some help with that aspect. As far as an adapter, why not use a standard 12gr setup? If it is going to be fed into an interim chamber, then an adapter seems like a waste of money.
 
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