air tank size for stock tires?

[GSequoia]

But you'll get a wicked head rush.

 

[ZomBrady]

CO2 actually = carbon dioxide

I beleive O2 (oxygen) and CO2 have different expansion/compression ratios which I think is why some people are using co2

Actually, the rate of expansion for both O2 and CO2 is same, they both follow the Ideal Gas Law: Pressure = (nR*Temperature)/Volume. The advantage to using CO2 versus just plain old compressed air, is that CO2 is a relatively stable gas that doesn't oxidize anything except under very specific reaction. On the other hand compressed air drops moisture as it is compressed and contains high amounts of O2, both of which play havoc with alloys and rubber compounds.

In some high end tire shops, they have taken to using compressed N2(nitrogen) since it is even more stable and increase the longevity of of the rubber compounds with in the tire. The problem with this though, is that once you pust compressed air in with the N2, is that you've just defeated the purpose of using N2 in the first place. . . . .

Tangent done now. . . .

 

[azdesertrhino]

OK, this is getting really confusing for me. If I understand correctly we are comparing compressed air in a tank (like you get at a gas station) compared to CO2 (carbon dioxide). Am I correct so far?

Now compressed air is just "X" amount of compressed air pressure in a tank where CO2 is in a liquid state that boils off as vapor is released and maintains a pressure unless you blow off a lot of vapor and your tank gets real cold and the CO2 can't boil off.

If I am reading this right, there is no way a tank holding compressed air will fill as many tires as a tank the same size holding CO2, or am I really missing something. hasta

 

[langer1]

OK, this is getting really confusing for me. If I understand correctly we are comparing compressed air in a tank (like you get at a gas station) compared to CO2 (carbon dioxide). Am I correct so far?

Now compressed air is just "X" amount of compressed air pressure in a tank where CO2 is in a liquid state that boils off as vapor is released and maintains a pressure unless you blow off a lot of vapor and your tank gets real cold and the CO2 can't boil off.

If I am reading this right, there is no way a tank holding compressed air will fill as many tires as a tank the same size holding CO2, or am I really missing something. hasta

Your not missing anything, there is a lot of confussion in this thread.

 

[langer1]

Actually, the rate of expansion for both O2 and CO2 is same, they both follow the Ideal Gas Law: Pressure = (nR*Temperature)/Volume. The advantage to using CO2 versus just plain old compressed air, is that CO2 is a relatively stable gas that doesn't oxidize anything except under very specific reaction. On the other hand compressed air drops moisture as it is compressed and contains high amounts of O2, both of which play havoc with alloys and rubber compounds.

In some high end tire shops, they have taken to using compressed N2(nitrogen) since it is even more stable and increase the longevity of of the rubber compounds with in the tire. The problem with this though, is that once you pust compressed air in with the N2, is that you've just defeated the purpose of using N2 in the first place. . . . .

Tangent done now. . . .

Your correct but co2 is a liquid, not a gas when compressed to 150# at 70 deg's
Oxygen is only in liquid state at -300 deg and about 250 psi.
Nitrogen is used in tire shops because the large molecules will not leak through cast aluminum wheels like air.

 

[ZomBrady]

Your correct but co2 is a liquid, not a gas when compressed to 150# at 70 deg's
Oxygen is only in liquid state at -300 deg and about 250 psi.
Nitrogen is used in tire shops because the large molecules will not leak through cast aluminum wheels like air.

Ah, but the amount of CO2 compressed to liquid at 150 lbs is the same amount of O2 compressed to 150 lbs, still gaseous. (actually there are variations in volume as the gases approach their critical states but they are miniscule.)

I was not aware that CO2 tanks kept the CO2 compressed in a liquid state. But this makes sense, since it gives you a constant pressure at 150 lbs/sqrin. I can defintely see how this would be useful in not having to have a 'High Pressure' regulator in the system.

As for the Nitrogen not leaking through cast aluminum rims. That seems more than plausible to me. But even for all my 'knowledge'(<---yeah right), all of that scientific stuff is pretty much snake oil IMHO.

 

[dmillion]

Your correct but co2 is a liquid, not a gas when compressed to 150# at 70 deg's...

Not quite. At 70° F (I assume you're talking Farenheit) CO2 must be compressed to about 900 psi before it will turn to liquid.

 

[langer1]

Not quite. At 70° F (I assume you're talking Farenheit) CO2 must be compressed to about 900 psi before it will turn to liquid.

Your right, my co2 tanks regulator only shows the reduced pressure not the tank pressure.
Because it's a liquid, not a gas it's sold by weight.
The pressure will stay the same as long as there is any liquid left, and there for it's usless to know the tank pressure like oyegen.

 

[langer1]

I brought this thread back up because I just tested this compresser
I paid $38.00 to my door.
I looks very well built and the test was a totaly flat 33x12.50x16.
It took this pump 4min's to fill this tire from 0 to 35# and thats without the engine running.

http://cgi.ebay.com/ebaymotors/ws/e...8057&ssPageName=MERC_VIC_ReBay_Pr4_PcY_BID_IT