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Posted: Sun Nov 04, 2007 10:49 pm
by Hubb
You don't have to worry too much about the bell reducer on the barrel, nor do you have to worry too much about the DWV elbow. It is after the valve, which means it is only subjected to pressures for a brief period. I would replace them eventually, however.

The couplings on the chamber, however, look like they are DWV.

I notice the CO2 tank. Is the launcher regulated? If not, then I wouldn't use the CO2. You may also want to add a pop-off valve.

Posted: Sun Nov 04, 2007 11:07 pm
by patton
i have a in line co2 air regulater that i usually feed in the pressure at 50 psi and for safety i have a 125 psi safety valve. what is the problem with DWV?

Posted: Sun Nov 04, 2007 11:09 pm
by Hubb
The problem with DWV is the fact that it is not rated to withstand pressure. It may hold 200psi and it may hold 2psi.

Edit: That's awesome that you have what it takes to run CO2. A lot of people will tell you that running it at 50psi with the DWV will be okay. It may be and it may not be. Personally, I've made launchers using DWV and never had any problems, but I won't make them anymore (pneumatics, that is) for the simple reason that it could explode. I like me and I want to keep liking me.

Posted: Sun Nov 04, 2007 11:14 pm
by knappengineering
Nice two t-shirt launchers! :lol: What size barrel are you using for them?

Posted: Sun Nov 04, 2007 11:19 pm
by patton
3" barrel works perfect, and ya after my first one blew up and put a few stiches on my buddies hand i am a little cautious with this new one. Thankfully i am only having to fire it off at 50 psi and am achieving 2x the distance of the orginal cannon thanks to the supah valve

Posted: Sun Nov 04, 2007 11:23 pm
by knappengineering
sounds good, I'm planning on making a 2.5" piston valve tennis ball cannon, maybe I can squeeze a small t-shirt in there. :lol:

Posted: Sun Nov 04, 2007 11:36 pm
by patton
you should be able to it all just depends on how your roll you t-shirt

Posted: Mon Nov 05, 2007 12:30 am
by unisonmind
HaiThar wrote:
unisonmind wrote:it looks like the couplings are DWV and if your couplings DWV your bushings are DWV as well cuz they fit all the way in the couplings i could be wrong but from the pics the sockets look real shallow
I don't think his couplings are DWV, and I've never seen a DWV bushing... =\
im not trying to be a ass this is just my opinion
if you look at the end of the chamber the the small bushing is pw thats way its doesn't fit all the way in the shallow socket of big bushing because its DWV

all the parts i think are DWV

the 2 coupling
the 2 big bushings
the Bell reducer
the 2 adaptors that you have attached to the supah valve
and the 90
and i cant see if the camber is cell core or not
just look at all these parts and make sure they don't say NSF-dwv

Posted: Mon Nov 05, 2007 2:44 pm
by patton
thanks for the help am i in danger at any moment or just down the road. and what are the pieces i am looking for going to say

Posted: Mon Nov 05, 2007 8:46 pm
by unisonmind
ya that thing can blow today a week from now or in 3 years from now some people have had cannons made from DWV that they have used for years with no problems and others have had cannons blow on the first shot but you just don't know thats why its just better to get all parts pw


you want all parts to say NSF-pw

and make sure your pipe doesn't say cell core on it

Posted: Tue Nov 06, 2007 12:22 am
by patton
thanks i just checked and my bushings are ok but one fitting says
NSF-dwv what does that mean

Posted: Tue Nov 06, 2007 12:28 am
by patton
NSF - dwv ? anyone

Posted: Tue Nov 06, 2007 5:31 am
by Ragnarok
patton wrote:NSF - dwv ? anyone
DWV - Drain, Waste, Vent.

Parts can both be pressure rated and marked DWV (If it's rated to 300 psi, it's certainly qualified for the transport of "sewage"), which may confuse but they are typically mutually exclusive.

A translation is usually "Not intended for pressure applications."
It's designed to take some gravity pressure fine - but gravity pressure seldom adds up to more than about 10-20 psi, past that, you can't be sure it will hold under pressure.

Posted: Tue Nov 06, 2007 2:21 pm
by patton
i know but is say NSF - dwv what is the NSF for isnt NSF-pw good

Posted: Tue Nov 06, 2007 2:57 pm
by williamfeldmann
It would need to say NSF-pw on it for it to be pressure rated. NSF is an acronym for a rating or standards body, I forget off hand what it actually stands for. The "pw" is the important part. If your part does not say "pw" then it is not pressure rated. You might notice that longer sections of pipe say both. That is because it meets both standards, DWV and PW.