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Unrated fitting question

Posted: Tue Oct 23, 2007 2:46 pm
by Pyr0man1ac
Does the (red) fitting need to be pressure rated? It comes after the sprinkler valve and isn't connected to the air chamber. However, I'm assuming that it will still have to withstand quite a lot of pressure when all the air escapes. (It is a 1" valve connected to either a 3, 2, or 1" barrel.) The reason I ask this question is I stupidly forgot to order these parts, and I don't want to wait another 2 weeks by ordering them off of sprinkler.com. My local hardware store provides 3 x 1" bushings, which is the part I need, but they are dvw. Anyone know? Thanks,

pyr0

Posted: Tue Oct 23, 2007 2:48 pm
by ShowNoMercy
Unless you have a really perfect seal in between your barrel and ammo, I would say go ahead and use it. However if you make your projectile too heavy or to tight all bets off.

Posted: Tue Oct 23, 2007 2:54 pm
by ALIHISGREAT
well it also depends what pressure you are going to use, i agree with ShowNoMercy though, you shouldn't use tight fitting heavy projectiles and it should be safe. i assume that as you are using a sprinkler you will use 100-150psi any more and i wouldn't trust the fitting.

Posted: Tue Oct 23, 2007 3:01 pm
by Pyr0man1ac
The projectiles I am going to use are: C batteries in the 1" chamber, soda bottles in the 3", and potatoes in the 2" barrel. I don't know how tight a fit the c batteries and the soda bottles are.

Posted: Tue Oct 23, 2007 3:06 pm
by MrCrowley
If anything it will just fly off, which could be dangerous. Just buy the parts of mcmaster.com they come a lot quicker.

Posted: Tue Oct 23, 2007 3:09 pm
by Pyr0man1ac
ok thank you.

pyr0

Posted: Tue Oct 23, 2007 3:09 pm
by DYI
I have used non-pressure rated ABS pipe and fittings for barrels on all of my launchers, and have used nearly 500 psi in some of them with no failures of any kind. PVC isn't as shock resistant though, so it may not work as well. The heavier the ammo, the slower the acceleration, and higher and longer the pressure spike.

Posted: Tue Oct 23, 2007 3:16 pm
by Pyr0man1ac
Is what I want a socket weld x pipe? (One end needs to have the 1" pipe slip into it, the other needs the 3" pipe to slid over it)

Posted: Tue Oct 23, 2007 3:45 pm
by MisterSteve124
Are you trying to get a female adapter (with the threads) or just the reducer/bushing part? If you just want the reducer/bushing part then you'll need a 3" coupling and a 3" x 1" bushing that is socket weld on both ends.

Posted: Tue Oct 23, 2007 3:52 pm
by Pyr0man1ac
This is what I need:

Posted: Tue Oct 23, 2007 3:57 pm
by ALIHISGREAT
if you have a pressure rated pipe on the inside and pressure rated ont he outside i see no problem with using it.

Posted: Tue Oct 23, 2007 4:29 pm
by Pyr0man1ac
Really? That's great... yeah, both pipes are pressure rated to well over 250 psi. I guess I'll just go downtown and buy the parts tomorrow! Thanks a lot!

pyr0 :D

Posted: Tue Oct 23, 2007 6:06 pm
by SpudUke5
Yea your barrel does not necesarily have to be pressure rated because i do have a ABS barrel on one of my cannon ( my first cannon to be correct) and it shoots fine. :D

Posted: Tue Oct 23, 2007 6:13 pm
by spudgunnerwryyyyy
First off the barrel recieves a pressure spike for only a few miliseconds, so like likmycrotch said abs works great because it is very flexible, so abs is fine, dwv pvc isn't cell core its just very thin, i see no problem in using that part as long as you don't shoot any thing that might get stuck in the barrel.

Posted: Tue Oct 23, 2007 7:40 pm
by noname
spudgunnerwryyyyy wrote: dwv pvc isn't cell core its just very thin,
Not true in the least. I've seen 8" DWV fittings that are over 1/2" thick. The main reason we don't use DWV is because it isn't made the same way, and the socket depths are much shorter than potable water fittings.