good plan or not?

[regre7]

I've been considering making a pneumatic cannon as my second spud gun, and I like the design the guy at PVC ballistics has here.

Does this look like a solid plan?

[CS]

Yes it will work. Why would he post plans if it didnt work? Anyways, I would suggest that you mod the sprinkler valve because the trigger assembly looks a bit costly. If you do make it do me a favor and use clear primer and glue.

[regre7]

I'm asking because my friend (who got me started on spud guns) used DWV (non pressure-rated) pipe for his chamber, and I just don't want to run across any plans with bad advice like that.

Also, how would I go about modding the sprinkler valve?

[beebs111]

this pagehttp://www.spudfiles.com/forums/viewtopic.php?t=305
good luck

[regre7]

Thanks for the link, but do I really have to mod the valve? Does it make that much of a difference? It looks pretty involved, and I've only got a week and a half left of Christmas break, not all of which I plan to spend on a spud gun.

I think I'll start construction Monday, once I get some money. Wait, 2" pipe is pretty cheap.... maybe I'll get started tomorrow. Too late tonight.

[beebs111]

you dont "have" to but it will make the setup alot easier(you wont need a huge ass project box with switches and battereys). and it will increase performance drasticly. when i modded the valve for my latest gun, it took me about 15 minutes to actually mod it and 6.50 to by the parts



if you know what i mean by that.....

[regre7]

What advantages does using an inline valve have over one that would be the U itself?

[drac]

The 180 degree valves with the Anti Siphon slightly choke flow. And don't use a "U". Use 90 degree elbows, most Us aren't pressure rated.

[julz]

wait wait wait, you said your mate used DWV (darinage) pipe for his pneumatic cannon? wow, i thought it would blow up, i mean, i use it fpr combuistion but that only get 50psi max ish.

how did that perform?

also, has ne1 got an idea of the pressure that DWV pvc can withhold?

[darkpyro]

dwv is really bad dont use it for pneumatics ever and be careful with combustion however if the dwv says pvc beside it it is fine and is rated to 100psi and over 8)

[beebs111]

dwv is safe for combustions and low pressure pnuematics stay at like 50-60 psi and you wont die

[regre7]

No, it wasn't pneumatic (fortunately). I didn't get exact measurements, but I'm guessing it was 1' x 4" chamber (DWV) and a 6' x 2" barrel (probably rated, that's the only kind you can find in 2" and smaller at our Lowe's).

also, has ne1 got an idea of the pressure that DWV pvc can withhold?

I was under the impression that it could take about 10 PSI. I think I read it somewhere while perusing some spud gun sites. It doesn't really matter, no one in their right mind would use it on a spud gun.

EDIT: Hang on, I just remembered that atmospheric pressure is something like 14 PSI (an atmosphere is around 13 or 14 PSI, I think).

Oh well.

[Shrimphead]

I'm making a fairly sized pneumatic with a 3" chamber. On the chamber it says dwv, but it also say nsf pw and pvc 260psi @ 73F
I just wanna make sure that this is safe to use, cause i don't want to die. It's just confusing that it says its pressure rated, but that it's dwv.
Does it sound safe to use???
thanx

[regre7]

I've never seen that, but as long as it's rated to handle the pressure, I'd say it's fine.

I'd also wait for a second opinion. A few hours waiting won't hurt. Extremely sharp shards of PVC will.

[boilingleadbath]

Shrimphead: If you can put 260 PSI (safely) in the pipe, you can drain sewage through it. Thus, most NSF-PW I have seen also has a DWV rating that reflects that.