pvc type

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elitesniper
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Sat Nov 10, 2007 12:19 am

um guys i have a question um. lets say i all i have is 2 inch pvc and my chamber is the same size as my barrel , so on my gun theres like a three feet barrel and the tank is also three feet and the both the same diameteras it 2 inch is that performance guna be ok? or poor? (cuase my dad wont let me get and more tubes so im stuck with 2 inch)
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singularity
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Sat Nov 10, 2007 1:04 am

i once made a 3" pneumatic mortar with about a 24 inch chamber and a 18 inch barrel, it could shoot a water bottle over 100 feet using only paper towels to seal it (there was a like a 1" gap in water bottle OD and 3" pipe ID).. of course that was at like a 45 degree angle. what the preformance really depends on is the projectile you are trying to fire
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elitesniper
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Sat Nov 10, 2007 1:11 am

so the chamber and barrel dont really matter much its just the weight and shape of the projectiles that mostly affect it?
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Zen///
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Sat Nov 10, 2007 1:13 am

And the pressure, but make sure your pipes are pressure rated.
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elitesniper
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Sat Nov 10, 2007 1:16 am

the pipe is sch 40 and says 450 psi so that should be good ?
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Zen///
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Sat Nov 10, 2007 1:27 am

Sure keep it 20psi below that and you'll be fine.
Don't use it in cold conditions though.
Pvc becomes brittle at cold temperatures.
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Fnord
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Sat Nov 10, 2007 9:28 am

If the pipe says 450psi, I would think he could use it at least 125... 20 is fine for dwv, but he's using nsf-pw.

as to the question: Try to make the chamber at least the volume of your barrel. At 125 psi, you could probably have a minimum C:B of .5:1, but 1:1 will give you more power.
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DYI
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Sat Nov 10, 2007 10:31 am

At 125 psi, the minimum C:B is actually ~.2:1. In theory, if the pipe is rated for 450 psi, it should be fine for 450 psi. Just don't be anywhere close to it if you actually take it that high. Plastic pipe has been known to have microscopic defects that can cause catastrophic failure, even below the rated pressure.
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elitesniper
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Sat Nov 10, 2007 10:46 am

thanks guys, but whats wrong is nsf -pw? and around here my temp is about 69 is that alright for my pvc?
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pyromaniac
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Sat Nov 10, 2007 4:03 pm

elitesniper wrote:thanks guys, but whats wrong is nsf -pw? and around here my temp is about 69 is that alright for my pvc?
The temp is fine. Nothing is wrong with nsf-pw its is what should be used not nsf-dwv. pw- pressure water dwv- drain waste vent.
:pottytrain3:
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DYI
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Sat Nov 10, 2007 4:31 pm

PW= potable water, NOT pressure water. PW and DWV are sanitary ratings, nothing to do with pressure. (but when you think about it, all drinking water delivery systems must, by nature, be pressurised).
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