Thanks again for the replies.. I am going to stick with a 1.5 x 12in steel chamber for now and just up the PSI to around 150 to get 200+fps out of the gun =)

Sprinkler valve data should be (according to those at Spudtech):

Cv: 6 (you have it on efficiency, you need to change this back to 'Cv')
Seat Diameter: 1.1"
Piston Diameter: 1.8"
Piston Mass: 0.8oz
Vent diameter: 0.15" (0.2" if your blowgun is modified for extra flow).


MrCowley ...

I say don't use steel on the tank. Use 1.5" pvc, it can take 150 psi.

I like the safety of steel.. I will shoot this thing off around several people (some are kids) and I just cant compromise on safety. My first pnumatic was pvc and held up to 150 just fine but there is always that off chance ...

Thanks for the reply MrCrowley - what are your thoughts on the size of the pressure chamber?

Hello,
I have been reading the site for a while and am in the process of building my 2nd pneumatic cannon. I have been using GGDT to run some tests and want to make sure I am using the application correctly. The image below gives a brief overview of my build and a screenshot with what (I think) is a ...