How many car tires can an Al 80 with 3,000 PSI fill?

[cool_hardware52]

None. Around 200-350 psi your auto tire will burst..........

Jokes aside, do the math. 77 cu ft at 1 ATA is what you have to work with.

You should be able to estimate the volume of the tire, circumference, width etc. Subtract the wheel.

Then consider the fill pressure which is in psi *gauge* not psi absolute, i.e. "50 psi" on the side wall is about 65 psi absolute.

Lets say your tire is 30" in diameter x 6" wide on a 15 inch rim. Rough numbers tell us the volume of the tire is (15" x 15" x pi x 6") - 7.5 x7.5 x Pi x 6" or about 4239 - 1060 = 3179 cu inches 3179/ 1728 = 1.84 cu ft

1.8 cu ft x (65/15) = 7.8 cuft at 1 ata.

Rough numbers, the actual volume is less due to tread depth etc. and the example ignores the tire starting at 1 ata (if you jack up the vehicle so the tire is not compressed.

I'd expect to be able to fill ~10 such tires with a full al 80, but I'd plan on only about 8

Tobin

 

[cool_hardware52]

I knew you smart guys would figure this out for me. There is still air in the tires, probably around 20-25 psi. I just need to top them off and I didn't think an 8 gallon tank with 150 psi would do the trick.

8 gallons is barely more than one cu ft. 7.48 gallons per cuft.

Tobin

 

[Bob DBF]

Would you rather have a compressor or another tank.


Bob

 

[tursiops]

8 gallons is barely more than one cu ft. 7.48 gallons per cuft.

Tobin

And the pressure in the 8 GAL tank will keep decreasing as you empty air out of it. Not good.

 

[northernone]

So... Avoiding the hypothetical math...

My 215/70/r15 tire, when on the vehicle, settled to 'empty' resting on the rim. A slow leak. 2hrs to go flat. Had air and no patch nor desire to change the flat mid dive expedition...

It takes a little under 500psi out of an al80 to fill it to around 34-35psi.

That's using a LP port hose fill adapter.

Regards,
Cameron

 

[wildbill9]

Depends....are you using nitrox? Everyone knows it's better than trash air......

 

[jblack]

I am trying to figure out whether to take my scuba tank Aluminum 80 (3,000 psi) to top off 12 RV tires or an air compressor with an 8 gallon tank near 150 psi.

Thoughts, advice?

not many

 

[2airishuman]

I find that I can top off (by 5-10 PSI) tires on 3 cars with an LP11.

I generally carry a set of tire plugs and a source of compressed air in my cars. Sometimes a repair is much easier than changing a tire.

I use oddball cylinders that I've accumulated as a substitute for shop air.

 

[67macoshark]

Depends....are you using nitrox? Everyone knows it's better than trash air......

What color valve stem cap for nitrox filled tires? And...do you need to oxygen clean the rims first?

 

[Johnoly]

And should you test for less than 5 ppm CO in the tire after filling it?
Nevermind,,,the tail pipe is right behind the tire.