Pneumatic Cannon Help!

[nathanhd123]

I am considering making a pneumatic potato cannon. It would be made completely of PVC-U. The air chamber (if thats the right name to call it) would be 4" and the barrel 2".

Is it safe to use a 2" Ball Valve instead of a modified sprinkler valve.

Also the PVC is pressure rated to 130psi does this mean I can take it up to this pressure or would I risk bursting the chamber?

Thanks in advance for any answers.

[jackssmirkingrevenge]

Is it safe to use a 2" Ball Valve instead of a modified sprinkler valve.

It's certainly safe, but unless you have some sort of spring mechanism to open the ball valve quickly, performance will not be as good.

Also the PVC is pressure rated to 130psi does this mean I can take it up to this pressure or would I risk bursting the chamber?

Certainly, provided you don't abuse it (ie drop it from the roof on to a hard surface, leave it in direct sunlight for the whole summer etc.)

The rating usually indicates the safe working pressure, actual burst pressure is likely over 300 psi.

[nathanhd123]

Is there any way of using abs and pvc in one cannon as I have heard that ABS does not shatter if the chamber ruptures?

[jackssmirkingrevenge]

http://www.spudfiles.com/spud_wiki/inde ... VC_vs._ABS

[mattyzip77]

you can use a 2 inch ball valve, however your performance will not be too good. If this is your first, I highly reccomend getting a sprinkler valve and modding it with a blow gun. Its easy, and is probably cheaper than a 2 inch ball valve!! Use RATED schedule 40 pvc!!! Do some homework in the wiki and browse the forums looking at other peoples cannons. The more you study, the better your cannon will be in the end!! You dont want pvc blowing up in your face, or anywhere near you for that matter. Be careful and aware!!!

[nathanhd123]

Do you guys see anything wrong with me using pressure rated PVC-U for it?

[jackssmirkingrevenge]

Do you guys see anything wrong with me using pressure rated PVC-U for it?

As long as you put it together correctly you should have no problems.

[jsefcik]

Id recommend using a sprinkler valve, When i started i use a 1 1/2 ball valve, performance sucked,

You can get a sprinkler valve in lowes, homedepot, but depends where you live, I had to order mine,

You can put a ball valve behind the sprinkler for safety

[sprayandprayboy]

Is there any way of using abs and pvc in one cannon as I have heard that ABS does not shatter if the chamber ruptures?

if u thread it togather rather than sovent welding then yes im my eyes

[Technician1002]

It is hard to find. They make a glue specifically for joining ABS and PVC. Due to one material being harder than the other, the joint is weaker and may fail if it is subject to flexing.

[mattyzip77]

""It should be noted that ABS cement will NOT work on PVC, or vise-versa."" per the wiki!! Is there a reason you want to use abs rather than pvc?? Im just curious!! pvc is less expensive and easier to get. my opinion is abs is brittle, and very thin compared to pvc. have you seen many abs cannons on spudfiles??? theres a reason!!! unless you already have it, then go with pvc!! 8) 8) 8)

[Gun Freak]

Matty, the reason is that it is hard to find. When abs fails, it doesn't explode like PVC, it just splits. It is very safe.

[MrCrowley]

my opinion is abs is brittle, and very thin compared to pvc

Wow.

You may find some ABS that is thin, just like you can find PVC spouting but in a lot of cases non-pressure rated ABS is actually better (ABS isn't really brittle by the way) than pressure-rated PVC due to its ability to absorb shock, withstand more extreme temperatures and it's tearing failing characteristic.

[nathanhd123]

How do you attach a sprinkler valve to pvc as they are usually metal aren't they?

Sorry for all the questions but this is my first pneumatic spud gun.

[nathanhd123]

Also is there any way of improving a ball valve as the sprinkler valves are a lot more expensive?