Help with fittings please!?

[joshywin]

So I'm making a pneumatic gun using an old fire extinguisher from the tip/dump. I managed to disassemble it okay but when it came to finding the right fitting, i'm clueless! I measured the diameter and the ID is 28mm. I looked for fittings of the internet and it came up with BSP fittings. I went to a local plumber merchant and he told me it was a metric fitting therefore BSP won't fit. So I searched the internet but I am so confused, I can't find any "28mm metric fittings". If anyone could help me with the situation I'd be grateful. All I'm wanting is something I can screw into the top and attach to some copper pipes. Fire extinguisher model: Annex I Directive 97/23/EC.
Can anyone help, it's only my first proper go at making one and I apologise in advance for my terrible knowledge on the subject.
I'm only 14

[jackssmirkingrevenge]

Fire extinguisher model: Annex I Directive 97/23/EC.

Sounds more like the specs it was made to than the actual model number.

I'm only 14

We could tell by the unnecessary bold text

As to your problem, this is some advice I had given in another thread, links might be dead:

Reducer: http://www.ebay.com.au/itm/2PCS-1-2-Mal ... ter-Reduce r-Brass-/250881413920?pt=LH_DefaultDomain_0&hash=item3a69b29320

(make sure the exposed thread is compatible with whatever you want to hook the tank up to!)

Epoxy for setting up the mould: http://www.ebay.com.au/itm/Araldite-AB- ... -minutes-R apid-GIFT-/270682624949?pt=LH_DefaultDomain_0&hash=item3f05f113b5

Epoxy for filling the mould: http://www.ebay.com.au/itm/Loctite-Mari ... ater-Sets- 50min-/250888044070?pt=LH_DefaultDomain_0&hash=item3a6a17be26

This would not be my first choice though, I would be more confident using something like this if you can find it cheaply, perhaps locally: http://www.ebay.com/itm/EPOXY-RESIN-MAR ... H-IMPACT-3 2-OZ-KT-/280255931847?pt=LH_DefaultDomain_0&hash=item41408e25c7

[joshywin]

Thankyou, I'll try using the epoxy method.
Roughly what PSI would you estimate the epoxy could handle holding before giving way?

[jackssmirkingrevenge]

Roughly what PSI would you estimate the epoxy could handle holding before giving way?

If done well with proper epoxy I would trust it to 500 psi or more.

I have to emphasise "if done well" though

[anarchy08]

linky link
http://www.solenoid-valve-info.com/sole ... s.html#NPT

[K8TOW]

i have used a fire extinguisher before and i use a 3/4 black iron from the extinguisher to the sprinkler valve from mcmaster-carr.then i use brass after that.