SpudFiles

Hi, well i am new in tis forum but i alreday posted my first gubn in an european forum but thers not much traffic i think.


So question is how much pressure an fire extinguiser can handel.


I am aking because i try to build an multi shot repeater and i need some kind of high pressure tank with a nice volume. Thinking of an 2 Kg fire extingisher.
I will work about 20 bar maybe more if it works like it should

2kg dry powder extinguishers are usually tested to 24bar, but operating pressure is not supposed to be above 10bar.

You need to provide more details about the extinguisher in question, and a picture might help too.

Define "High Pressure" as it pertains to this. Put a number on it. ie. 400psi



There are different types of fire extinguishers.

CO2 fire extinguishers will have a rated working pressure of 1800psi.

The dry chemical extinguishers I have seen were filled to 200psi, I cannot remember the proof pressure though.

I don't know the regulations where you are, so it might be easiest if you were to carefully look over the labels and stamps on the extinguisher.

That is where I found the proof pressure on the one at work.

A link with some pressure specs on a dry chem extinguisher;

http://www.partspoint.nl/content/downlo ... EET%5D.pdf

Most of these (that you would be interested in) seem to be tested to the same certification requirements,

Certified to the Pressure Equipment Directive PED 97/23/EC, to the Marine Equipment Directive MED 96/98/EC and EN3. Capacity is 1 kg.

http://www.anaf.biz/estintori.php?ids=14&extc=2&

It is reasonable to believe that these are all tested to the same proof pressure of 25bar (~360psi)

Hope that helps.

Welcome to Spudfiles.

He wants 20 bar.
Just because it's tested to 25bar, does that mean it's safe for regular use at that pressure?

No, that's just what was required to meet the certification.

It's important to give some thought to manufacturing process.

Costs must be kept down to remain competitive, while the product must meet certification standards, and be able to remain safe while dealing with "consumer stupidity".

The wall thickness of the extinguisher body will be determined by these factors.

Without actual dimensions and material specs, it's impossible to determine "just how far" the bottle can be pushed safely.

That being said, I'm pretty confident that 20bar would be entirely safe. Consumer "stupidity" and liability laws being what they are these days.

hm, co2 extinguishers are realy expensive here i saw some but allways about 100 euro more than 120 $ i need an air tank or pressures about 20 - 50 bar. i am not shure how much pressure my gev can handle. its for an multi shoot gun. and i like to have a big chamber for much shoots. it will be filled by a fridgy. i could also buld the chamber put of 1 ot 1 1/2 sh 40 pipe but i like to have volume of 2 -4 liter

Daniel, you can't put 50 bar in a large chamber, unless it;s a CO2 or HPA tank..

Big steel fittings aren't up for the job.

If you want to use high pressure I recommend using smaller diameters.

thanks, btb du u think 1 inch water sh 40 pipe can handle 50 bars. and it would be nice if u could look my other post.

http://www.spudfiles.com/forums/viewtop ... tml#245299


i know u real know al lot about spudgunning so what u think about the max pressure of the qev in my post?

Those sorts of QEVs have been used to 45bar, and the piston tends to rip before anything else breaks.

I would say that sch40 1" pvc would never be able to handle 50 bar, try steel or brass.

Oh boy,
PVC Will NEVER EVER EVER be able to safely handle 50bar(50*14.5=725Psi) for supudgunning use.
You will HAVE TO use metal be it copper, brass or iron at these pressures. Also maybe I missed it but how the hell do you plan to make 50bar. Fridge pump would cut it all other common things would not, and a stirrup pump would take u a day or two to pump up a larger chambre to the right preassure. You should maybe start a bit smaller lets say 20bar and then slowly build up. Or do it like my self, i have been plannign my first gun for nearly a year now so it will be able to go up until around 800psi safely, but I am machinign it from solid aluminium, making things very safe at all times.

john bunsenburner wrote:Oh boy,
PVC Will NEVER EVER EVER be able to safely handle 50bar(50*14.5=725Psi) for supudgunning use.
You will HAVE TO use metal be it copper, brass or iron at these pressures. Also maybe I missed it but how the hell do you plan to make 50bar. Fridge pump would cut it all other common things would not, and a stirrup pump would take u a day or two to pump up a larger chambre to the right preassure. You should maybe start a bit smaller lets say 20bar and then slowly build up. Or do it like my self, i have been plannign my first gun for nearly a year now so it will be able to go up until around 800psi safely, but I am machinign it from solid aluminium, making things very safe at all times.

+1, take that advice. Don't put those pressures in PVC.

I also agree on his statement- start small and build up, or spend a lot of time and consideration planning. Admittedly my next major build- and one of my largest will be completely machined from stock, with months going into it's planning. I've got pages and pages of plans, drawings etc to work from, drawing inspiration from guns such as the airforce condor, Girandoni repeater, modern stock reservoir airgun et cetera.

If you're using a manual pump for those pressures definitely use a 2 stage pump, or even 3 stage if you excel at fabrication.

With the right pressure rating PVC could take 50 bar but for a lot less in weight and cost you can get metal tube which isn't 50% of it's own volume in wall thickness.

well ok lets say i have a chambre of pvc that can hold 50bar and drop it or it gets hot on soem corner, or its left out in a cold night, it could simply blow apart leaving me blind or severly hurt. Is that really a risk you are willing to take?

Same could be said for PVC rated to 200psi, hasn't stopped it being used (even in massive capacities) despite the fact that everyone knows it's a fairly brittle plastic that shatters on failure and is banned for use as pressurised gas line in industry.

If it's used at its rated pressure and kept safe then happy days, the only time its downsides appear is when it gets a nasty shock load where it doesn't want it like an elbow. Then you get the bad news of using high energy pressurised gas instead of low energy pressurised liquids it's meant for.

Okay guys nice^^but i use sch 40 metal pipe not some kind of pvc.

http://cgi.ebay.com/1-1%2f4--INCH--STRU ... dZViewItem

something like that.

I wont ever use pvc.... but i am not shore if an 2 inch or 1 and 17" inch pipe is made fpr such pressurs. and dont worry about getting the pressur. is was at a junkjard and i have about 5 working fridge kompressors. a over 200 bar o2 gas bottle witch i can reg so 5 - 60 bar.