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Topic: Compressed gases  (Read 6897 times)

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Haz Mat

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Compressed gases
« on: April 11, 2004, 05:08:57 AM »
Safety Issue:
I teach cadets the "IAFF Operations Level" at the Phila Fire Academy, A few asked questions on cylinders and the amount of product they can hold.
I have all my notes at work, but a quick summary follows:

Example: Acetylene tanks, lets say the 3ft size, is approx 2cuft in volumn, with temp constant at 70deg F, I believe the books says it can hold 300 cuft of gas. How do I prove it??

(I'm working by memory...haha...I'm also losing that battle)
Now the total contents will be different for every gas.

This also applies to our FIRE CODE.
A total of 750 CUFT of compressed flammable gas per control area. So how do I prove the total volume of a particular compressed gas in total CUFT?
I need to show the building owner that he may be in violation of the Fire Code.
Some of the gases I see alot are: Ammonia, CHlorine, Propane, Acetylene and many others. WHY is this important?
I found 6 working Acetylene carts on the 6 ft floor of a building. I know this has got to be a Fire Code violation, but I have to prove it!
if Vol of tank is only 2cuft, how do I prove there is approx. 300 cuft of acetylene gas per tank?
So, more than 2 1/2 tanks is in violation of the Fire Code. I need to prove it.
Any help is appreciated.
Remember, working by memory.
Thanks Ron

gregpawin

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Re:Compressed gases
« Reply #1 on: April 11, 2004, 05:46:39 AM »
So, I'm not sure if I am going to give you the answer you want but... either you're wanting to calculate the current amount of gas contained in those cylinders, which you could do by the weight of gas full and empty... or from its indicated pressure using PV=nRT.  However, if you're sure that each tank can hold a maximum 300 cubic feet of gas... and its only 750 cubic feet of gas are allowed, its obvious that 6 tanks is too much.  Perhaps they used most of the tanks up and are technically under the 750 at the moment, but if we're talking about keeping at 750 all the time... the rule should just be 2 per area period; no one's going to keep track of the extra gas.

So, if you just want to prove that there's more gas than allowed and want some proof... just add up all the volumes and pressures indicated on the tanks and compute the final number of moles of gas... times this by 22.4 and you get liters of gas, which you can convert into cubic feet of gas yourself.  By the way chlorine and ammonia are toxic while propane and acetylene are flammable.  Also, ammonia can be liquid when pressurized.
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Mitch

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Re:Compressed gases
« Reply #2 on: April 11, 2004, 06:14:54 AM »
The lab I work with uses acetylene tanks all the time. If you can wait till Monday, I can get an answer for you then.
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