Air cylinders and safe pressures

[chinnerz]

Hey guys
I have been getting mixed responses in my research and I would gladly appreciate any input into this.

I need to know the maximum safe/ sane pressure rating for the following items:

A fire fighters oxygen tank,( I don’t know whether it is the same as a scuba tank)

A medium sized (I think there are different ratings for different sizes) bbq lpg cylinder.

And those small propane tanks for portable gas welders
I do not need an exact number, I was just looking for an air supply tank which is good for 350-500 psi.

From the research I have done I know that tank explosions are the worst!

[ramses]

Scba tanks should be marked. My friend's dad works at a fire station, and IIRC, they use ~4.5ksi. I doubt they would use O2. would you walk into a fire with a tank of pressurized oxidizer strapped to your back?

As to propane, their working pressure has to be at lease 200psi, since that is propane's vapor pressure at 90*F. IIRC, they hydrotest at 380. Tech would know and post pics.. lol

[jackssmirkingrevenge]

would you walk into a fire with a tank of pressurized oxidizer strapped to your back?

Probably

[ramses]

ok fine, pure oxygen

[chinnerz]

so, what you are saying is, i am in the clear if i use the oxygen tank

[D_Hall]

I doubt they would use O2. would you walk into a fire with a tank of pressurized oxidizer strapped to your back?

You may be surprised.

Once upon a time I did my share of firefighting in the Navy (as does every sailor). We didn't use tanks though. Instead, we used a solid chemical pack rebreather that had an interesting property... Upon contact with water it generates reasonably large quantities of oxygen. Normally, this means that the moisture in your breath results in oxygen to breath. But if it comes in contact with large quantities of water? *KABOOM* As in, you'll look like a suicide bomber when the smoke clears.

Now, do remember.... You have quite literally a firehose in your hand. You're spraying large quantities of high pressure water everywhere.

Do try to keep that rebreather dry, mmmmkay?


(Here's what we used... http://en.wikipedia.org/wiki/Oxygen_Breathing_Apparatus)

[chinnerz]

Hmm, just a wee bit off topic..

I have decided to go with the tank but Its not my tank and I don’t know if it has any markings labels, what I do know however is that it is apparently full of foam... and has a 5mm hole in the base my friend says that it is more that 4mm thick but he is not sure. But it will current hold 0 psi

I was actually planning on making a rifle with a friend of mine, and we are planning on attaching a quick connect to the base and also have one on the top.

So am I still in the clear? Or have these mods ruind the tank and put it in a un salvageable state

[D_Hall]

So am I still in the clear? Or have these mods ruind the tank and put it in a un salvageable state

I'm sure others will disagree, but personally I'd send that tank to the scrap heap unless I knew more about it (materials, construction, etc.) so that I could do some additional analysis.

[jimmy101]

I doubt they would use O2. would you walk into a fire with a tank of pressurized oxidizer strapped to your back?

How do you figure?

A tank of compressed air is a tank of "pressurized oxidizer". (OK, i'm just being a pedantic PITA).