Hi, I'll search for a larger tank, thanks for the help. I'm sure I'll have more questions.
Glad to help. Im in this boat as well.
If you are in the EU you might can get the SCBA system from the source or at least locally there.
My nitro cylinder valve sits at 150 bar (out of 350). Is that still enough gas/pressure for my 10L tank to cib using SCBA?
150 bar = 2175 psi. 10L tank is about the same as a 80 cubic foot tank.
The conversions are confusing. But from what I know SCBA systems operate btwn 85-130 psi.
Now how long a tank would last at a rate that is efficient....Im not sure, here is my attempt using SCUBA method
Water Volume = 10 L
Working Pressure = 150 bar
Ideal capacity 10 ×150 ÷1.01325 = 1480 L
Z Factor =1.0263
True capacity 1480 ÷1.0263 ≈ 1440 L
Usage: (assuming 15L/min for CTB) 1440L ÷ 15L/min = 96 minutes
This is assuming that regular Air is being used. Nitrogen compressed acts differently, but I would assume not that much.
Someone will need to check the mathematics of this.
Thanks for the reply. I just wanted to clarify that I am well aware that nitrogen is used, as well as am quite well-versed in SCBA basics. My question was referring to testing the SCBA or, more specifically, the exhalation resistance, as well as generally getting used to the feel, doing practice runs, etc., and that I'd like to use compressed air for this testing (since nitrogen would make me pass out, with potentially leaks/problems/discomfort while exhaling, etc., which could make CTB fail or make it less comfortable, such as with SI/anxiety)).
The problem is that compressed air is used for many things (like welding, power tools, cutting, cleaning, etc.), and that there is a certification here in Europe (EN 12021) for compressed air specifically used for firefighting or scuba diving, which has had potential contaminants removed. My question was whether or not compressed air without this certification is safe to use for testing, or if it can lead to lung problems, dizziness, health problems, etc., since it may contain small traces of CO, CO2, water vapor, methane, etc.
Oh sorry, I didnt know you meant for Testing purposes.
I obtained the same Air tanks that are typically used with the SCBA systems for the fire fighters.
There are plenty available for purchase. If you can get one, I would recommend it. They are used only for normal air and are clean with no contaminants.
The issue I had was that in the USA, there are laws that only allow air tanks to be filled that fit some time parameters.
One is that the tank must be within 15 years of manufacturer to the day you want to fill it. The manufacture date is printed on the tanks for this purpose.
Another is that the tanks must be tested every 5 years. The testing agency will place a stamp on the tank showing that is has been tested.
In the EU it appears there is a similar requirement (I am not sure though).
But I would recommend attempting to get one of these scba air tanks and have it filled to the normal pressure with normal air.
Usually before they fill it, they can clean out the tank.
As for other types of tanks....that the risk. Usually tanks are designated for the gas they will contain.
I would think a Helium tank or CO2 tank would be fine.
They would take the valve off of the tank, clean it out with water & soap...dry it....then replace the valve...then fill with normal air to the correct pressure.
What type of tank have you acquired?
I ordered a helium tank which according to the manufacturer is 99.0% pure, it is 0.40m3.
I also ordered one of those gym backpacks that close elastically, maybe now I'm just missing a tube; or could I try to inflate the backpack like a balloon and immediately put it on my head?
(Assuming you referring to the hood method)
I think a tube that would supply a constant flow to a sealed hood would work.
the consensus is that 15L/min should work. CTB time needed at least 15 min....so 15L/min X 15 min = at least 225 L of expanded gas is needed.