DWV Safe?

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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Extrusion
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Fri Oct 06, 2006 11:18 pm

Hi i have built my cannon and fired it 15 times already and just now stupidly relized it is PVC DWV nothing bad has happened so far is it safe to continue using it the fuel im using is butane and propane thx for the help.
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MrCrowley
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Fri Oct 06, 2006 11:45 pm

propane no...butane not sure but normal deoderant should be fine, i have used butane in my all dwv combustion and its fine but that was once or twice.
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CS
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Sat Oct 07, 2006 12:16 am

Talking out of your arse again MrCrowley, eh?

A aersol fuel and a propane fueled combustion will yeild fairly close peak combustion pressures. Propane is used more commonly used in more advanced configurations because its able to be metered, its cheap, etc. If the issue is truely safety, id rather be worried about if you properly welded you socket joints. Either way your dealing with realtivly low pressures, so you should be fine.
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MrCrowley
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Sat Oct 07, 2006 12:38 am

well....maybe :roll: ive heard from other senior members not to use propane with DWV as it can peak at around 70psi, but my combustion is all DWV with one reducer thats down piping and ive used butane

edit:hey pimp how much is mapp gas in the states?is it the same price as propane?i saw a bottle like the one used on that awesome hybrid the other day for $70NZD! at a hardware store.
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frankrede
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Sat Oct 07, 2006 1:07 am

DWV is a common label on many types of pipe.Pressure rated or not. The question isn't if it is DWV or not, but is it pressure rated?
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brumby
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Sat Oct 07, 2006 6:48 am

I use DWV pipe all the time for my combustion cannons and I use aerosol butane and propane. I have been told that DWV is pressure rated at 100 psi so combustion cannons are fine.

Also, the DWV pipe that I use has a pretty think wall, so I think its fine. Wouldn't use it in pneumatic guns though
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Extrusion
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Sat Oct 07, 2006 9:41 am

Ok thats awsome it says DWV but it also says 280psi on it so i should prob be ok.
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boilingleadbath
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Sat Oct 07, 2006 6:24 pm

Nice 3" pipe, extrusion.

Pipe is marked with all the ratings that apply to it; sch 80 pipe could very well be marked DWV - because you could use it for drainage.
(never mind how dumb it'd be)

This cannot be interpreted as "DWV is pressure rated". It's not; but pressure rated pipe is normaly rated for DWV usage too.

...but anyways, are your fittings marked "NSF-PW"?
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Extrusion
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Sat Oct 07, 2006 7:29 pm

Yes it had [NSF-PW] on it to.
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mark.f
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Sat Oct 07, 2006 7:39 pm

Is this the fittings or the pipe?

I have never seen dually marked fittings.

To clear this up, what is the ASTM number/rating? D2466 is on pressure rated fittings, (SCH-40).

(See, this is why I love ASTM ratings. :D )
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frankrede
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Sat Oct 07, 2006 11:20 pm

My pipe says DWV and is pressure rated but for the most part ignore the DWV label and look for a pressure rating.
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