Possible pressure vessels

[SniperMan]

Hi all. I've been lurking round here for some time and finally decided to sign up.

Been into the combustion scene years ago with tennis ball/spud guns - Gave it up when every man and his dog decided to make one and the authorities got on to them.

Now 10 or so years on, I've made up a pneumatic BB sniper shooting 7mm BB's using a barrel seal valve, and some 'SMC' branded pneumatic valves for a semi auto. It can be permanently connected to my air compressor and using a 'bolt' for reloading from a 20bb magazine. Laser and 3-9X50 Scope on order....

At the moment, almost the whole thing is made from the black poly pipe commonly used for popup sprinkler manifolds (rated at 230psi and is black).

It's working a treat but to get a decent size 'tank' i've had to use what they call 'Sprinkler Risers' - basically just a length of straight poly pipe with 3/4 BSP threads.

Now, that bit looks a little ugly so i was thinking of replacing the 'tank' with something that looks a little better (and is smaller). I was thinking of using something like a small fire extinguisher bottle but that is too big for what i need (only about 600ml needed). So, that got me thinking

What about the aluminium 'Sigg' bottles (or variations) - They come in all sorts of cool colours, designs and capacities. Has anyone used or tested one of these for thier ability to hold pressure? I emailled sigg a week or so ago asking what sort of pressure they can hold (or at least what they are tested at) but with no reply so far. However they DO say on thier site they are safe for carbonated drinks.

The next option i was thinking was an empty 'Soda Stream' aluminium bottle (rated at 850odd PSI so definately safe) but i think that would be a little on the small side for capacity.

Any other ideas?

[trae08]

1 liter bottle i know those will hold a good amount of pressure

[SpudStuff]

they have been known to hold up to 160 psi or burst ar very low pressures. i would reccomend just using pressure rated pve to build your chamber

[boilingleadbath]

Carbonated beverages can produce about 90 PSI during storage.

Many deoderant bottles look like they are about 600ml, and their propellent will generate about 100 psi at room temp. - and of course, they are designed to contain whatever the pressure is at higher temperatures. Which should be a fair amount.