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Black Hole... My first Cannon
Posted: Sun Dec 23, 2007 9:19 pm
by CuddlyBurrito
So here is my first cannon.
Specs:
Barrel: 2' of 2"
Chamber: 2' of 3"
Valve: 1" Modded Sprinkler valve
thinking about painting it flat black..
I'm def going to do some more stuff to it.. i'll give yall some damage pics tomorrow, i had some fun with little oranges and a golf ball with some wadding all about at 70 psi. but its late and i dont want to get the cops on me.
o ya don't hate on my priming job its going to get painted. and i am going to put a block and a strap on it in the morning
Questions and statements start now.
Posted: Sun Dec 23, 2007 9:24 pm
by cwazy1
it looks okay, alot like my first cannon but i have high standards on looks . there are 2 things i would comment about, the dwv parts and the large pilot volume.
Posted: Sun Dec 23, 2007 9:25 pm
by SpudUke5
I dont think those elbows are pressure rated. If they are, then they should say nsf-pw on then some comment us back and tell us if it says that.
And the hose on the sprinkler valve connected to the blowgun valve can be reduced in order to increase efficiency.
dont make JSR come here and tell you......
EDIT: SOB cwazy you got here first, only if i made my comment smaller

.
Posted: Sun Dec 23, 2007 9:30 pm
by CuddlyBurrito
yes the elbows are pressure rated. and i can shorten the hose and i probably will just mount on the valve but i cant complain with the results. (sent a orange about 150 yards.)
Posted: Sun Dec 23, 2007 9:32 pm
by BigGrib
yeah the dwv fittings scare me, and definitely shorten the hose you'll notice a difference, ohyeah and clear primer helps it's what i use
Posted: Sun Dec 23, 2007 9:33 pm
by cwazy1
hehe
umm those elbows/90 bends are deffinitly not pressure rated. i'll bet my crotch on it =P
Posted: Sun Dec 23, 2007 9:38 pm
by CuddlyBurrito
well... crap.. you think it'll be ok? or should i repair it... i guess the guy at Lowes lied to me...
Posted: Sun Dec 23, 2007 9:41 pm
by Novacastrian
Well not really, they would be able to hold some pressure........
Posted: Sun Dec 23, 2007 9:42 pm
by SpudUke5
Well look on it for nsf-pw. It looks to me like is dwv but you can look again.
Some people will say its good to a certain pressure like 70 or so, but i wouldnt risk it. I have used dwv fittings past 100 and it didnt fail but just to be sure, you might want to try and get pressure rated fittings.
EDIT: Hehe, paybacks a biatch cwazy

Posted: Sun Dec 23, 2007 9:42 pm
by cwazy1
well just because they arent pressure rated, it doesnt mean it wont be able to hold pressure. poeple have done tests with it to like 200psi, i'd recommend only going to MAX 100psi and never never never drop it and also when filling it, point those elbows in another direction.
Posted: Sun Dec 23, 2007 9:43 pm
by CuddlyBurrito
well my compresser only goes to 100 psi anyways.. old POS
i can do that.
EDIT: just asking is it the joint that blows off or the elbow shattering?
Posted: Sun Dec 23, 2007 9:44 pm
by daberno123
lesson #1 never listen to the guy at lowes. They'll probably be ok if you stick to the 70 psi you've been shooting at
Posted: Sun Dec 23, 2007 9:55 pm
by mark.f
Look for and ASTM rating on the fittings and do an online search at ASTM.org. That'll tell for certain whether they're made for pressure or not, if you're still interested.
Here's what I suggest, though. Cut off the elbow assemblies, leaving that length of 1" coming from the chamber and the small length of 1" coming from the valve. Reinstall the same setup with some pressure rated elbows, (should say 'ASTM D2466' if they are pressure rated SCH-40, or 'ASTM D2467' for pressure rated SCH-80), and a socket going to that stub coming from the valve. It looks to be of sufficient bottoming depth for 1" pipe, but check as I could be wrong. It doesn't look as if you can unthread it from the elbow assembly, as I see purple primer where they meet.
Also, I would check your 3" cap, coupling, and bushing as well. While they look to be pressure rated from over here, if you got them from Lowes or Home Depot, they're more often than not DWV, (past 2").
Good job on the first build, (although I would have commented on things such as your excess pipe length between fittings, if I hadn't already posted too much in the first place on other things), and good luck on the re-haul, if you so choose to do so.
Posted: Sun Dec 23, 2007 9:59 pm
by mopherman
If I were you, I would replace those elbows with threaded street elbows. They're pressure rated and make the entire setup look much tighter. It also allows for perfect barrel alignment. You could do with a much longer barrel to.
Posted: Sun Dec 23, 2007 10:02 pm
by PVC Arsenal 17
Inefficiency frustrates the INTJ!
Eliminate the hose. Use NSF-pw.