The internal volume of the CCFC-048
It should be 48 cubic feet of gas at working pressure (I assume 2000 psi) i.e. some 1370 liters of gas at 137 bar which gives you 10 liters of volume.
It is probably 48 cubic feet at the redline pressure which IIRC is 150 bar which is 2175 psi.
10 litres actual volume feels about right. 20 pints of beer.
Scuba 40 cuft at 200 bar is 5.7 liters, and proportionally from there, 48 cuft at 137 bar is 10 liters. If it’s specified at 150 bar (which I doubt) then it’s 11 liters.
I think it is probably closer to 9 litres. My earlier rough estimate, based on a guess of the internal dimensions, was 8.5 litres (0.0085 m^3).
Here are the specs from the website:
Pressure is listed as 2216 psi (152.79 bar).
Volume is listed as 48.2 cubic feet (1365 litres).
Converting 1365 litres at 1 bar to 152.79 bar => 8.93 litres.
Converting 1365 litres at 1 atmosphere to 152.79 bar => 9.05 litres.
Y’all making it too complicated.
The bottle takes 1.136 m^3 at 150 bar.
A refill from 37.5 bar (25%) to 150 bar takes 0.852 m^3
BOC bottle has 15.5 m^3 at 300 bar, and 7.75 until it is down to 150.
So you get 9 refills from 25%. (7.75 divided by 0.852)
Everything else is a rounding error.
Peter wrote:
1 × 1st stage reg with 4 outputs.
Thanks for clarification – do you have a link to that connection you have. Presume you just have a tube (or x2) from the regulator to the EDS using the normal 4 output regulator.
Peter wrote:
Yes, W is the standard welding gas depot size. 200 bar. Everything else is uncommon, and the smaller ones don’t cost much less so the debate would be solely over easier hauling back to the depot.
So I may just look at the Standard W size. However storage wise by the aircraft will need to be horizontal in a box. I see online that if secured safely, there’s no way this is an issue and the air is compressed not LPG.
Anyone know if this is an issue and why? Because this is the easiest solution to storage.
Cobalt wrote:
Y’all making it too complicated.
You are right! Assuming that the gas volume figures given by BOC and Mountain High are on the same basis (which seems a pretty reasonable assumption), then using that as the base for the calculation makes things a lot simpler.
I presume you meant 1.365 m^3 rather than 1.136 m^3 for the Mountain High cylinder.
Mountain High
1.365 m^3 at 152.79 bar
0.313 m^3 at 35 bar
So each refill uses 1.052 m^3
BOC
15.5 m^3 at 300 bar
7.894 m^3 at 152.79 bar
So BOC cylinder has 7.606 m^3 available for full refills of the MH cylinder.
7.2 full refills from the BOC cylinder.
Y’all making it too complicated.
You’re right but the Americans (British?) 
invented this cuft marking of the tanks and usage of psi. Europeans specify volume in liters and pressure in bars – easy to remember and calculate.
Peter wrote:
I pay annual rental and then pay for each bottle swap
Same here. And since I don’t use the system a lot, a yearly swap will do
