air tank

[Zombie]

I have some paint ball gear, one of the things being a 62 cubic inch tank that usually will be filled to about 2700 psi.
I was trying to think if I could use this to air up my tires(as in would it have enough capacity to air them up from about 15psi in a 31x10.5r15, to at least 25-30 psi.

I was trying to think of the math to figure this out, and I got tired.

any ideas

steve

[sn4cktime]

Feeling a little OCD so did some number fumblings for you.

Follow if you dare.  First off, I was thinking who figures out volume in cubic inches, obviously only small volume thinking there.  So I found a converter and cranked it into cubic feet.  http://www.metric-conversions.org/volume/cubic-inches-to-cubic-feet.htm You get 62 in³ = 0.035879 ft³.  So, I then flipped that to ounces as that's what the US Power Tank guys have on their handy little chart here: http://www.powertank.com/charts.specs. Did that via the power of a converter on my mac. From 0.035879 ft³ you get 34.354375 fluid ounces.  The chart generalizes it a bit as PSI isn't directly mentioned but PSI can sort of be compared to output power in relation to volume (which is kinda dependant on CO2 being a liquid and converting to gas as it depressurizes, that's why they measure CO2 via weight, but that's getting WAY too technical for a "how many fills" question). SO, you're ALMOST at 40 oz. there which is about a 1/4 of a 5lb tank when empty.  SO, using the OTHER handy chart there (keeping in mind that's the IDEAL situation there, you'll get less.  If you aired your 31's from around a 30 ish PSI to around 10 you'd have a 20 PSI difference to refill.  You'd get about 15 refills with a 5lb, so like 15 / 4 = not quite 4 tires.

TA-DA!!  I'm S-M-R-T-R than everybody! Or so my Mom tells me.

Pretty sure the logic is fairly sound on the 1/4-ish amount thing there.  If you look at the fill up chart a 5lb has 1/4th the amount of a 20 lb.  But the weights ARE a little wonked...  So maybe +/- it by a factor of.... 2 tires.  So 1.5 to 6 individual tire fills.  And I just looked up a pic of that sized tank and am going to hazard a guess towards the low end of that logic....  But, I could be way off, just fill it up, park at a 7-11 with a compressor and dump your tires.  Actually do it, and let me know the results.

Any regulator you could fit on that thing will have an awful flow rate which will hack the PSI WAY down, so if it DID work, it would be slow.  And you'd be draining the cylinder so fast it might just ice up solid....

Prognosis: get a bigger tank (10 lb min) and a PowerTank, Source or comparable HIGH flow pass-through or adjustable regulator.  Bed time for me!

[Zombie]

I started playing around too after a bit.
I forgot to label what I did last night, so it may not really make sense. I talk about pounds as pressure in the tank.
I figured that the inner surface area of the tire was about 6070 square inches, multiply that by about a 10psi change(15-25) you get about 60700 pounds needed(I have no idea if this makes sense now, but it did at the time)
the tank I figured has an inner surface area of about 98 square inches, multiply by the 2700 psi that should be in the tank you get 264000 pounds(again, not really making sense right now).

to get to 25 psi, it would need say 151000 pounds(would have to equalize at the end), so only about 110000 pounds to play with.
so I kinda have a feeling that it would not really work.
but I am sure gonna try.
I will get an adaptor to put an air chuck on the end of the hose and see if it works(this may be in a few weeks as I have way to much going on right now)
but I will let you know.

if I am not mistaken, the tank is regulated to have 850 psi output, so I would have to have something else to drop it to about 125 -150 or so to make ot work well.

[dac]

The whole air tank idea sounds like trouble, but I don't have one so I'm not sure about the process to go get it filled.

I like my little viair pump.  It fills all 4 tires.  Get's stored on my shelf at home, and works the next time with out worry of running out of wind.  I don't have to plan on getting it filled.  For me the pump seems like less of a hastle, and you don't have to worry at all about transporting compressed air cylinders in a vehicle that you know will be bounced around a lot down the trail.

[Zombie]

that is what I was thinking about too.

tanks can be filled at just about any paintball place, but I have a feeling that I would not have enough volume to do the job.

just kinda wondered when I was moving some things in the basement.

if the end broke off, it would be a small explosion I think(very unlikely, but.....) it would cause me a few issues, so maybe back to the drawing board.

[cLAY]

There are lots of people running compressed gas cylinders(CO2) or N for onboard. Dion from the FWS runs one in his Toyota and uses it for airing up, running tools and activating his ARB lockers. He really likes it and has no issues with the ARB lines freezing in the winter. Has tons of volume for reseating a bead running air tools and can air up about 20-30 tires(he runs 38s). He keeps two tanks on hand so that when one runs out he just swaps it out and fills the empty one at his leisure.

There are kits you can buy online that comes with lines, mounts, regulators etc. I think I read somewhere that an O2 regulator from an oxy/acteylene setup works well.

Here we go: this site shows how many tires can be filled off one of their systems. For a 37" tire you could fill it 26 times with their smaller tank(80 cubic feet).

https://ultimate-air.3dcartstores.com/Specs_ep_35-1.html

Also the tank is portable, so if someone pops a bead 3 vehicles ahead of you on the trail you don't have to jockey around vehicles to get up there to help out. Just pop it out of its mount and carry it up there.

[sn4cktime]

You CAN use an O2 reg, but the CFM often isn't high enough (look for manifold regulators).  It's not so much the PSI you want, you want a high VOLUME of air at a high pressure for tires.  300 PSI @ 10 CFM's will take a while to fill tires, but the high pressure will freeze regulators up.  250 PSI at 45 CFM (PowerTank reg) fills adds 20 PSI into 4 tires at the same time in around 30 seconds.

And like cLAY mentioned, they'll push beads back on which I've never heard of any onboard compressor doing.  Source and PowerTank both sell a cheaper non-adjustable flow-through regulator (set at one output PSI) that aren't that expensive but will still crank out the higher volume numbers.

Here's a link from VIAIR on their Heavy Duty onboard compressor with fill times, can't seem to find their CFM rates. http://www.viaircorp.com/OffRoad/Specs/10005_fr.html  That's PER tire.

[tubby]

Feeling a little OCD so did some number fumblings for you.

Follow if you dare.  First off, I was thinking who figures out volume in cubic inches, obviously only small volume thinking there.  So I found a converter and cranked it into cubic feet.  http://www.metric-conversions.org/volume/cubic-inches-to-cubic-feet.htm You get 62 in³ = 0.035879 ft³.  So, I then flipped that to ounces as that's what the US Power Tank guys have on their handy little chart here: http://www.powertank.com/charts.specs. Did that via the power of a converter on my mac. From 0.035879 ft³ you get 34.354375 fluid ounces.  The chart generalizes it a bit as PSI isn't directly mentioned but PSI can sort of be compared to output power in relation to volume (which is kinda dependant on CO2 being a liquid and converting to gas as it depressurizes, that's why they measure CO2 via weight, but that's getting WAY too technical for a "how many fills" question). SO, you're ALMOST at 40 oz. there which is about a 1/4 of a 5lb tank when empty.  SO, using the OTHER handy chart there (keeping in mind that's the IDEAL situation there, you'll get less.  If you aired your 31's from around a 30 ish PSI to around 10 you'd have a 20 PSI difference to refill.  You'd get about 15 refills with a 5lb, so like 15 / 4 = not quite 4 tires.


TA-DA!!  I'm S-M-R-T-R than everybody! Or so my Mom tells me.

Check out the big brain on Brad. You must be an engineer or come from an engineering background.

[cLAY]

There's also the flammable aerosol method of reseating beads...... That's always exciting!

[cLAY]

Thats also a good reason to run a narrower rim, easy to seat the bead. I run a 12.5(or 13.5) tire on an 8" rim. The tire self seats without needing a huge blast of air.

[Bnine]

Check out the big brain on Brad. You must be an engineer or come from an engineering background.

Maybe if his name was Brad.

Im pretty sure Tyler's a welder

[tubby]

Sigh...nothing gets past you Billy.
It's a line from the movie " Pulp Fiction"  said by Samuel L. Jacksons character
Yeah, I know that Tyler is a welder, and a  former Wal-Mart Ulysses tire pimp

[Bnine]

It's a line from the movie " Pulp Fiction"  said by Samuel L. Jacksons character

You mean when he's talking to Brett? Well why didnt you say so