The valve is a prototype, an all aluminium high pressure version is soon to come in the future. By high pressure I mean around 800-1200psi, not difficult to do at all. It will be machined out of series 6800 aluminium, thats what is available and is very close to series 7000.
Anyway, enough of that. I can't really give away any specs, if I were to describe it I would say something close to a mechanically operated piston valve.
I will give you a pic and a video, the cannon itself is quite small, it has a 32mm barrel and a 40mm chamber. I have only tested it today at low pressure with toilet paper as the projectile. Which you can imagine doesn't yeild the best prefomance. But it works, and thats all I was aiming for.
There is some more developement to do here but the concept is looking good.










 Pressure is just materials.
  Pressure is just materials. The chamber on the high pressure model will be linked to the valve/barrel via high pressure hose anyway.
  The chamber on the high pressure model will be linked to the valve/barrel via high pressure hose anyway. 


