Fill Calculator Confusion???

[UCChris]

So I was looking at how many times I could fill my HiPac'd 2400 with an Air Venturi 90 cu in 4500 psi SCBA tank.

So I looked up a calculator http://www.airgunsofarizona.com/Tanks/FillCalc.html

I inserted all the information

Capacity is 90 cubic inches (0.092 cubic feet)

Tank pressure is 4500 psi

I'm filling to 2000 psi

I'm probably refilling at 1000 psi

And the volume of a HiPac is 13 cc.

Apparently I'm not even going to get one fill out of it???

Hence the confusion...

[eelect]

The 90ci tank capacity is  15.6 Cubic feet
You should get around 200 fills

[Ribbonstone]

Best esimate of volume of a 2240 length HiPac is 30-33CC's.

[UCChris]

Best esimate of volume of a 2240 length HiPac is 30-33CC's.

Oh, thanks. I got the volume from someone else, so that must have been a mistake.

The 90ci tank capacity is  15.6 Cubic feet
You should get around 200 fills

Oh! Thanks for clearing that up. For some reason when I plugged it into a cubic inch to cubic feet calculator it said something else.

[Ribbonstone]

Alex (the HiPac owner) gives 30cc's as the volume.  But I don't think he included the volume inside the valve, so I add on 3cc's.

Have to mention a couple of things.  Tank filling that small a volume (and without a gauge on the air tube) makes it way easy to over fill.  Also makes it way easy to fill so fast you have  a heat problem (air going into the tube compresses...which generates heat)...so fill very-very slowly (just barely crak the tank valve) with an eye to the fill gauge.

[UCChris]

Sounds good guys. Thanks!

[rsterne]

Paintball tanks are rated by their "water volume", ie the actual internal volume of the tank.... To find the amount of air (at 1 bar) the tank holds you have to multiply by the fill pressure (in bar), in this case 4500 psi /14.5 = 310 bar.... so the amount of air in a full 90CI/4500 psi tank is 90 x 310 = 27900 cu.in which is 27900/1728 = 16.1 cu.ft....

Bob

[UCChris]

Paintball tanks are rated by their "water volume", ie the actual internal volume of the tank.... To find the amount of air (at 1 bar) the tank holds you have to multiply by the fill pressure (in bar), in this case 4500 psi /14.5 = 310 bar.... so the amount of air in a full 90CI/4500 psi tank is 90 x 310 = 27900 cu.in which is 27900/1728 = 16.1 cu.ft....

Bob

  I think I understand...

[rsterne]

Put simply, there is 16.2 CU.FT. of air inside a 90 CI tank at 4500 psi.... so the tank size you use for a fill calculator is 16.2 CF....

Bob

[UCChris]

Put simply, there is 16.2 CU.FT. of air inside a 90 CI tank at 4500 psi.... so the tank size you use for a fill calculator is 16.2 CF....

Bob

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