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Fire extinguisher

Posted: Fri Dec 12, 2008 2:11 pm
by airman
Is it possible to reload an empty dry chemical fire extinguisher with air, to use as a chamber for an airgun? If so, how?

Thank you

Posted: Fri Dec 12, 2008 2:15 pm
by POLAND_SPUD
is it possible...? yes it is... the problem is that they aren't cappable of holding high pressure

if you want to use high pressures (well more than 120 psi) you should get a CO2 extinguisher

Posted: Fri Dec 12, 2008 2:41 pm
by Gippeto
The dry chem fire extinguisher I have is marked as having been proved to 575psi. More than a propane tank.(375psi)

I believe that the fully charged pressure is in the order of 200psi.

The problem is with matching the threads on the bottle. They may, or may not be pipe thread. I have not checked any dry chem extinguishers.

Check your fire extinguisher for proof/working pressure markings, as there exists the possibility that it differs.

If you don't find any, find something else to use.

Posted: Fri Dec 12, 2008 2:50 pm
by SP00K
I've seen specs on other sites about fire extinguisher tanks, the biggest problem is finding an extinguisher with the proper threading, Other people have just welded a pipe into the top of a fire extinguisher.

Posted: Fri Dec 12, 2008 2:59 pm
by airman
My extinguisher is rated up to 300 psi. I only want to know if it's possible to reload it with air. How do the specialized companies reload the chemicals in it?

Posted: Fri Dec 12, 2008 3:49 pm
by POLAND_SPUD
ohh sorry... it happends that where I live most dry chemical FE are made from PVC as they do not have to hold high pressure...
anyway if you can get a metal one I've never felt safe using mine at anything above 150 psi so finally I scrapped it



just make sure you got rid of that white powder... I am sure it can dammage some more advanced valves


EDIT
there are companies that reload them with chemicals but they do not reload it with air.... mine had a regular 8g CO2 cartridge inside - which was quite surprising I though they work in a different way

I thought you wanted to use it as a chamber/air reservoir... simply connect it to whatever you use to pump your guns and that's it...

Posted: Fri Dec 12, 2008 4:54 pm
by jitup
I don't know if you can find and extingisher like this, but they used to have them where you can fill them up with water, hook up to compressor and pressurize. My grand parents had one several years ago and threw it out :cry: to bad I wan't into spudding then.

If you can't find on like that, tap a small hole for a threaded quick release coupler. I would tap it near the middle if the dome on top. If you do this don't take it above 160 psi. You would be weakening the structure of the tank, and I am not sure how well it would hold up above 160 psi.

Posted: Fri Dec 12, 2008 5:24 pm
by SP00K
You can still find refillable ones for about 30 bucks if that's all you're looking for. Just go check out instructables.com and type in fire extinguisher.

Posted: Fri Dec 12, 2008 5:49 pm
by nibbler125
i have an old liquid fire extuingsher i found in my basement. but the date on it was back from the 1980s lol. and it says it can only hold like 130 psi max

Re: Fire extinguisher

Posted: Fri Dec 12, 2008 6:03 pm
by MrCrowley
airman wrote:Is it possible to reload an empty dry chemical fire extinguisher with air, to use as a chamber for an airgun? If so, how?

Thank you
http://www.spudfiles.com/forums/dual-fi ... t5803.html

:)

Posted: Fri Dec 12, 2008 6:16 pm
by psycix
Largest problem is to get anything connected to the thing. They probably dont have standard threads and welding or epoxy would be the solution.

Posted: Sat Dec 13, 2008 5:26 pm
by airman
It's a refillable extinguisher but I sure would like to know how they do it. Do they simply press the handle and plug a fitting at the end. Or, do they unscrew everything?

My other concern is with the threads. They might not be NPT.

Posted: Sun Dec 14, 2008 7:32 am
by psycix
My other concern is with the threads. They might not be NPT.
Thats what I said in my previous post. :)
You will have to:
-epoxy
-weld
-drill and tap new threads
if you want to connect it.

Posted: Sun Dec 14, 2008 10:02 am
by john bunsenburner
Me, being a curious nerd, once watched how they refilled our schools expired chemical fire extinguisher. What the guy did he had these co2 cartidges and just connected them out sides, there was a little shhhh sound and then he dis conected it. If my memory is correct that is, but why dont you jsut use an old bulk tank i got 7 of them lieing around and have no use fore them and they have normal theads, ask in an aquarium store.

Posted: Sun Dec 14, 2008 10:38 am
by Hotwired
I've got a used powder FE in my room.

The squeeze trigger bit at the top unscrews and pulls out a long core from inside the metal bottle and inside the core lives a 30/28 co2 cartridge to blast the powder out.

It's rated to 10.5 bar but also notes it has been tested to 24bar ~350psi

I can't tell what the threads are though, if I get round to requiring it I may just end up getting a matching thread cut on a fitting professionally.