How safe are fire extinguishers for storing pressure?

[ham_machine]

I currently use a small foam fire extinguisher to store a maximum pressure of 240psi of air (on my potato launcher). I'm considering buying a better bicycle pump that will reach pressures of 300psi. Is this safe? What is the bursting pressures for fire extinguishers, I have looked everywhere but cant seem to find much about it. Does anybody else use fire extinguishers, what kind of pressures do you store in them? And how safe is copper pipe for storing large pressures of air?

[jakethebeast]

As far as i know these tanks are usually rated 240psi, but the burst pressure is 3-4x higher than the rating, usually

As far as I'd consider, 300psi would still be somewhat safe if your tank is in good shape but if it blows up don't blame on me

[Gun Freak]

It usually says on the tank what the operating pressure and test pressure is... unless you took the label off.

[Zeus]

If it's water, 100 roughly. Dry powder, 200 odd is the operating pressure. CO2 extinguishers are around 900 operating.

[ham_machine]

It usually says on the tank what the operating pressure and test pressure is... unless you took the label off.

Yeah, I may have painted over it a while back!

[bravootome]

i use fire extinguishers for my guns. there are few models:
1- that have a co2 small tank (like ones for airsoft) inside it and you recognise it by the plastic head . Those are not recomanded for high pressure as they are made from very thin AL. But i overload one of them to 23-25 bar(didn't had the guts to go higher) and didnt explode, yet!. ( Don't try if only take precaution tests )
2- that stores the pressure inside it, the head is made of bronze and they are usualy made of iron,steel or gross Al.
You may read on the bronze head 27 bar- this is its working pressure but it hold 40 bar. also precaution overloading tests before you use it to high pressure.
3. there is a spray type extinguisher but it is too thin and it doesnt worth testing it....
4....
5...not tested

[Dig_Gil]

It usually says on the tank what the operating pressure and test pressure is... unless you took the label off.

Not in my country, they don't...

[jrrdw]

Not in my country, they don't...

Do you even use PVC where your at? You're p8robably the 1st member from Antartica. 8)

[Dig_Gil]

Have you seen the John Carpenter's film "The Thing"? As far as I can tell, these fire extinguishers are actually flamethrowers.
But seriously, although I don't live in spain, these labels are eerily familiar to those I find: http://www.extintorescelta.com/album/pr ... mal_13.jpg
http://juan.aguarondeblas.es/uploaded_i ... 788911.JPG
The difference is that these happen to accurately tell kind of agent instead of just saying "ABC powder" or "AB agent" and also mine have a circle of months with the last maintenance's date cutout instead of a "best before date" like those in the pictures.

[jackssmirkingrevenge]

Thanks to the internet, I read "Murcia" as 'MURICA!

[ham_machine]

Since writing this post, I have done allot of research into the pressures that powder fire extinguishers and copper pipe can withstand. I will share my findings in case anyone out there is interested as I was, in case anyone is slightly worried about the pressures as I was.. As you know, different fire extinguishers hold different pressures depending what they contain. The research I have done only includes Powder extinguishers and 15mm copper pipe.

Powder Fire Extinguishers -
Working pressure - 12-15bar (175-220psi)
Test pressure - 21-25bar (304psi- 362psi)
Hydro-static Test Pressure - 30-35bar (435psi-507psi)
Minimum body Burst pressure - 50-55bar (725-797psi)

Apparently this rule can be used on all fire extinguishers -
Test pressure - Shall not be less than 1.3 times the working pressure
Burst pressure - Shall not be less than 2.7 times the working pressure

I found a bit of information on 15mm x 0.7mm copper pipe -

I quote - "A 15mm x 0.7mm copper pipe will burst at 3480psi", "a solder fitting will burst at 5000psi" and "The working pressure of 15mm copper pipe is 840psi"

I had written this information into my pad a while ago, then used this to write the information up onto here. So sorry, but I am not able to link any sources to this information. I currently pump my powder fire extinguisher up to 24 bar (350psi). Be extremely careful when working with high pressures!