Air tank volume question

Nimrod

Degenerate Jeeper
NAXJA Member
This may be more appropriately posted in the Tools and Garages forum, but I figured it would get more views here. The moderators can always move it if so inclined.

I’m thinking of getting an air tank, not to mount up as part of an onboard air system, but just to bring along on the trail or leave at camp to fill tires faster than my portable compressor. Space is an issue, so I’m looking to go small. My question, specifically, is this: will a 2.5 gallon tank rated to 150 psi hold enough air to fill four 35x12.5x15 tires from 10 psi to 32 psi? I’m no math or physics whiz, and I haven’t been able to find the answer on line. If anybody has some practical experience or knowledge that can shed light on the question, please post up. Thanks.
 

Rob Mayercik

NAXJA Member #920
NAXJA Member
I doubt it - I have a 5-gal Wal-Mart special that's rated for about 125psi (never taken it above 100, though).

I bought it to try and blow out the sunroof drains on my DD, but I never found it to have enough capacity for the 31s on my XJ (I've used it once or twice for the mower tires, but they max out at 10psi). Makes a dandy air duster, though :)
 

Trouble

New member
no, 2.5 gal might have enough to dust off your dash board if that.

with your size tires it might fill maybe 1-2 psi. I have a 2.5 gal tank hooked to my 12v compressor set at 90 on/ 120 off. a quick spurt of air from the air nozzle to dust off my desk and it will kick on the compressor.

I say run co2 but realize even with a 10# co2 it will only fill so many tires. For example, if you use your co2 to put raise your tire pressure 20 psi per tire ( 10 psi to 30 psi) you will only be able to do that about 16 times.

i have several compressors between vehicles. viair 400p, viair 450c, a few smittybilt 2781. i tend to use the smittybilts more often as they are faster. Puma has a nice compressor with tank setup for 12v and has pretty good fill times. Of course ARB has their $$$bling setup so does extreme aire and oasis but those are out of my price range.
 

Nimrod

Degenerate Jeeper
NAXJA Member
Thanks very much for the input. I guess I’ll just stick with the compressor and resign myself to the slow fills for the time being.
 

ehall

NAXJA Member
NAXJA Member
I once did the math to fill four 35" tires from 10 to 30 psi, it was about 20 gallon tank at 125 PSI.

35" tire has 3.47 cubic feet of air at 0psi (atmo), 5.83 cubic feet of air at 10 psi, 10.55 cubic feet of air stuffed into the tire at 30 psi. Difference of 4.72 cf between 10psi and 30psi. 18.88 cf for four tires. 1 gallon to 0.133681 cubic feet. 15 gallons at 125 PSI nets 19.06 cubic feet. Probably need 20 gallons for comfort.
 

lazyxj

NAXJA Member #1310
NAXJA Member
CO2 has a lot to recommend it. I bought a 10-lb CO2 kit for Polyperformance almost 15 years ago and it is still working fine.
https://www.polyperformance.com/poly-performance-co2-kit

The 10-lb bottle usually lasts 6-12 months before needing a refill. It's quick and powerful enough to run a 1/2" air impact or other air tools.
For small jobs needing an air nailer, grabbing it is a lot easier than dragging my home compressor or 150' of hose around.
When you don't need it, leave it at home.It gets refilled at the local bar/home brew supply shop for about $15
 

ljobbins

New member
CO2 has a lot to recommend it. I bought a 10-lb CO2 kit for Polyperformance almost 15 years ago and it is still working fine.
https://www.polyperformance.com/poly-performance-co2-kit

The 10-lb bottle usually lasts 6-12 months before needing a refill. It's quick and powerful enough to run a 1/2" air impact or other air tools.
For small jobs needing an air nailer, grabbing it is a lot easier than dragging my home compressor or 150' of hose around.
When you don't need it, leave it at home.It gets refilled at the local bar/home brew supply shop for about $15
So how many times do you think your ten pound co2 tank will fill 35’s?
 

devildog0

NAXJA Member
NAXJA Member
Ive got a 20lb CO2 tank i keep at home or take with me if im taking the trailer since weight is less of an issue. Its been my stand in "compressor" for about a year now because im between air compressors. I use it to airup tires and run airtools. I have to exchange it about every 3 months or so.

Ive got a much smaller, lighter and handier 5lb bottle i take on the trail with me and to run tools away from the shop.

If you go this route i wouldnt bother with Powertank unless you like spending money. Find a used bottle on craigslist or something like that and exchange it at the local welding supply when you need it refilled. Lots cheaper just make sure the hydro test date is good on any used bottles you buy. You can get a co2 regulator anywhere for the most part either adjustable or fixed pressure and high or low flow.

Sent from my SM-G892A using Tapatalk
 
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lazyxj

NAXJA Member #1310
NAXJA Member
Power tank claims a 10 lb. Bottle will do 16 tires airing up 20 psi.
https://powertank.com/pages/tire-air-up-chart
I can get 10+ fill ups, on four 33"s, going from 12-psi to 24-psi, out of a 10-lb CO2 bottle. When mixing off road with pavement, I run at 18-psi and go up to 24+ psi, for towing home.
No need to raise the pressure 20-psi unless you have beadlocks and run at single digit pressures.
Shopping around, the Polyperformance kit is about as cheap as you can go, with new gear.
 

devildog0

NAXJA Member
NAXJA Member
Al,

A Power tank CO2 will be your best bet. Can even run air tools for a time if you need to.
Powertank is expensive. If you have the money then by all means grab one. But my CO2 setup runs airtools and was far cheaper than anything from PT.

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lazyxj

NAXJA Member #1310
NAXJA Member
Powertank is expensive. If you have the money then by all means grab one. But my CO2 setup runs airtools and was far cheaper than anything from PT.
Power Tanks sure look nice and considering they cost over twice as much as a Poly Performance tank kit, it should .

10-lb Power Tank CO2 kit. $506
https://www.amazon.com/Power-Tank-PT10-5240-CB-Package-Armorcoat/dp/B004M9M6X4

10-lb Poly Performance CO2 kit. $237
https://www.polyperformance.com/poly-performance-co2-kit
 

denverd1

NAXJA Member
NAXJA Member
what about going to welding supply store and getting a bottle with 800 psi of air in it? thinking the 5 pound will do plenty for what I'm trying to do. air up tires, maybe run air tools. The bottle is about $50, refills are $5.
 

Trouble

New member
Air tank at 800 psi wont do much , maybe 3-4 tires. plus there is no protection for the valve or regulator unless the supplier has some kind of shield. My scuba tank is a 88 cu @ 3500 psi

Ive seen bad things happen to scuba tanks when they fall over and loose a valve. Also some states have certain laws on transporting an air pressure vessel.



CO2 fill ups are about 10-15 bucks around here, prices fluctuate but have been pretty low around here. you can build your own setup and use a fixed regulator for a little over $100, plus it will most likely be DOT certified so you dont get sued when in an accident and your air tank becomes a rocket.
 

denverd1

NAXJA Member
NAXJA Member
Air tank at 800 psi wont do much , maybe 3-4 tires. plus there is no protection for the valve or regulator unless the supplier has some kind of shield. My scuba tank is a 88 cu @ 3500 psi



Ive seen bad things happen to scuba tanks when they fall over and loose a valve. Also some states have certain laws on transporting an air pressure vessel.







CO2 fill ups are about 10-15 bucks around here, prices fluctuate but have been pretty low around here. you can build your own setup and use a fixed regulator for a little over $100, plus it will most likely be DOT certified so you dont get sued when in an accident and your air tank becomes a rocket.
I would of course have a regulator on it.... so you're saying there's not significantly more volume of air in a tank with that kind of pressure?

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XJEEPER

NAXJA Member # 13
NAXJA Member
This may be more appropriately posted in the Tools and Garages forum, but I figured it would get more views here. The moderators can always move it if so inclined.

I’m thinking of getting an air tank, not to mount up as part of an onboard air system, but just to bring along on the trail or leave at camp to fill tires faster than my portable compressor. Space is an issue, so I’m looking to go small. My question, specifically, is this: will a 2.5 gallon tank rated to 150 psi hold enough air to fill four 35x12.5x15 tires from 10 psi to 32 psi? I’m no math or physics whiz, and I haven’t been able to find the answer on line. If anybody has some practical experience or knowledge that can shed light on the question, please post up. Thanks.
I have a 2.5 gal tank plumbed inline with my Viair 450C (100% duty cycle) and it takes about 12-15 min to air up all four 295/75/16 tires from 15 -> 32lb street pressure at the end of the trail. The first tire airs up quickly, the other 3....less quickly. This setup has worked for me for 11+ years. It also powers my ARB lockers.

I typically run with a group and they run similar compressor setups, so it takes everyone approx the same amount of time to air up at the end of the trail.
I guess if the goal is to win the tire air-up race, then a big CO2 tank will earn you a trophy, or if you break enough on the trail to need air tools to facilitate the repairs, then a full CO2 tank will trump an electric compressor/tank setup.
 

denverd1

NAXJA Member
NAXJA Member
I have a 2.5 gal tank plumbed inline with my Viair 450C (100% duty cycle) and it takes about 12-15 min to air up all four 295/75/16 tires from 15 -> 32lb street pressure at the end of the trail. The first tire airs up quickly, the other 3....less quickly. This setup has worked for me for 11+ years. It also powers my ARB lockers.

I typically run with a group and they run similar compressor setups, so it takes everyone approx the same amount of time to air up at the end of the trail.
I guess if the goal is to win the tire air-up race, then a big CO2 tank will earn you a trophy, or if you break enough on the trail to need air tools to facilitate the repairs, then a full CO2 tank will trump an electric compressor/tank setup.
that's pretty funny. the tire air-up race....

Actually, just see no reason to pay someone like powertank 5 bills for something I can do much cheaper. I carry a a small compressor with me for times when I roll a bead.

I trailer to and from the ride spot anyway, so I've already won your silly race. Rarely break, so don't think I'll need the tank or the tools, but we're all here to talk about jeeps, right? !!!1
 
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