How much air does an LP85 hold at 2400 PSI?

[CaveSloth]

My Faber LP85 has a little sign near the valve that says 2400. How much does this tank hold when filled to 2400 PSI? What about when overfilled to 3600 PSI?

 

[rjack321]

85cf at 2640

The tank factor of an lp85 is just over 3cf/100psi. 3.2 actually
85/26.40 = 3.2cf per 100psi
24 * 3.2 = 76.8cf
36 * 3.2 = 115cf

Roughly and will depend a little bit on the exact gas because of compressibility issues with helium.

 

[Lorenzoid]

85cf at 2650 . . .

Wouldn't that be "2640"? Ten percent of 2400 is 240, so 2400+240 = 2640.

 

[rjack321]

Wouldn't that be "2640"? Ten percent of 2400 is 240, so 2400+240 = 2640.

Sorry fat fingered that. yes 2640. although 10psi doesn't matter in the end.. And I did it twice so I fixed that lol

 

[CaveSloth]

My tanks say the following:

FABER MADE IN ITALY M8303 04/1871/ 198
TC-3AAM-184/DOT-3AA 2400 REE 66

What all that mean and what is my personal "tank factor"?

 

[tursiops]

Without the unnecessary nonsense of tank factors, if the tank holds 85 cuft at 2640, then it holds
(2400/2640) * 85 = 77 cuft at 2400 and (3600/2640) * 85 = 116 cuft at 3600. Simple proportions, at least for an ideal gas, which tanks factors don't accommodate anyway.

 

[Lorenzoid]

. . . and what is my personal "tank factor"?

"Tank factor" is a term used to describe the ratio between pressure and volume for any given tank. In other words, how many cubic feet per psi does it hold. For convenience of doing calculations, tank factor is generally expressed in cubic feet per hundred psi.

 

[rjack321]

Without the unnecessary nonsense of tank factors, if the tank holds 85 cuft at 2640, then it holds
(2400/2640) * 85 = 77 cuft at 2400 and (3600/2640) * 85 = 116 cuft at 3600. Simple proportions, at least for an ideal gas, which tanks factors don't accommodate anyway.

"tank factors" are just a way to use the same ratio to explain how algebra can be used to figure out the volume at any pressure

My tanks say the following:

FABER MADE IN ITALY M8303 04/1871/ 198
TC-3AAM-184/DOT-3AA 2400 REE 66

What all that mean and what is my personal "tank factor"?

M8303 is a code for Faber
04/1871/198 is the serial number
TC3AAM-184 is Transport Canada 3AA standard, metric pressure of 184 bar
DOT-3AA 2400 is US Dept of Transportation 3AA standard 2400 psi
REE is reject elastic expansion in milliliters - used by the hydroshop

The volumes for your tank at the pressures you asked about are above. Along with the algebra to calculate the volume at any pressure.

 

[CaveSloth]

Then I looked more and found another marking:

09 * 04 +

 

[CaveSloth]

"Tank factor" is a term used to describe the ratio between pressure and volume for any given tank. In other words, how many cubic feet per psi does it hold. For convenience of doing calculations, tank factor is generally expressed in cubic feet per hundred psi.

I was asking what is the factor for my personal tanks.