Sprinkler Valve size

[Sean]

I plan on making my first pneumatic gun and have a question about the size of the valve. I want to have a 3/4 inch barrel to shoot paintballs that's 24-30 inches long and a 12 inch chamber that's 3 inches in diameter. I bought a jar-top 3/4" sprinkler valve but am wondering.. Should I return it and go buy a 1"? Also, do you think my size for the chamber is ok? thanks for your answers, I really like spudfiles

[SEAKING9006]

It should be fine.

[jr]

The barrel and valve match perfectly, if the valve is to big it could over power the barrel. The only advantage I see is if you want to use the valve on a later cannon but at that point you would probably just buy another valve.

with a pnue. you want to be between a 1:1 and a 4:1 C:B. But I'm sure you know that from all your research!

[Sean]

with a pnue. you want to be between a 1:1 and a 4:1 C:B. But I'm sure you know that from all your research!

Yes I remember something about that statement. I've taken others people advice and read a lot of the spud wiki.. From other questions I've seen, I can tell others do not

Thanks for your responses

[jr]

Be sure to post it in the pneumatic cannon showcase when you get it completed! 8)

[pizlo]

There is an advantage that noone said,
Your barrel is the ultimate constriction of air. So theoretically a valve with an opening larger than the barrel adds no extra flow. While no extra flow is added, a 1 inch valve will be open to 3/4 of an inch faster than the 3/4 inch, this will increase performance (a little). I think the real advantage of a 1 inch is the use on later guns, an the ability to put a 1 or 1.25 inch barrel on it.

[MrCrowley]

Your chamber is pretty over kill. You will get better results and efficiency with a foot long 2" chamber and a 1" sprinkler valve. If you can return, I would recommend doing so. You should notice a increase in the power.

[Sean]

yeah I was looking at the ratio numbers and they just didn't look right.. I was actually thinking the same exact thing about the 2 inch. i was just thinking 3 inch because i already had some but buying some 2 inch wouldn't hurt, thank again everybody

[MrCrowley]

Well you could always use the 3" for another cannon.

[Sean]

Hmm I think I'm going to keep the 3/4 inch valve and use the 2 inch chamber instead. If I'm correct, with a 24 inch long 3/4 barrel, 2 inch 12 inch long chamber it makes it 3.56:1 ratio but with a 30 inch barrel it makes a 2.85:1 ratio. Would there be a significant difference if I used one over the other?

[pizlo]

30 inch barrel would give you better performance for sure.