SpudFiles

i currently have 4'x3" PVC DWV as my chamber. I was wondering if anybody knows hte PSI rateing on it.. its standard SCH40. I didn't know if the DWV ( guessing its drain waste vent ) andi need to know if it will hold 150PSI +.. i know regular schedule40 will but don't know about this DWV. Just want to make sure i'm safe..

It's probably not safe. But then again, who knows? (pimpmann or gort probably)

DOes it say nsf-pw on it anywhere?
All pvc says dwv so dont give me that.

What part of the chamber is DWV? if its the endcaps, then i would recommend replacing them to all sch40 PVC, because the DWV blows out very easily.

Remember, remember, remember, sch 40 only denotes the thickness!!! You must make sure it is pressure rated lest it blow up in your face. If it says nsf-pw on it then it's probably safe. If it says nsf-dwv then your gun won't work and you should use it as a combustion or something. Just as a side note, don't use bell reducers use bushings. Reducers aren't pressure rated but it's a common mistake so I'd just like to mention it.

Yeah, as squeaks said above, it only describes the thickness, DWV is thin walled and isnt really good for pressure applications, I suppose if there was no altenative to the DWV pipe then thats about it, the launcher wont be powerful at all due to the low pressure that DWV can hold. According to my past experiences, DWV has a pressure MAX of 30psi, and i mean maximum, as soon as you start to see those endcaps expanding, stop, otherwise face the consequences, so therefore i wouldnt use it, I would strongly recommend that you rebuilt the chamber to all pressure rated pipe and fittings.
So in closing, and the answer to your questions (well, due to past experience) DWV fittings will only hold up to 30psi, pushing that, and your pushing your luck.

Max of 30psi, thats bullsh*t people have taken then safely to 100psi, though I do not recomend using DWV in a pneumatic, DWV if dropped with 100psi in it will probably be bad

Oh and squeaks someone said on spudtech you can get pressure rated bell reducers they are just rare,(ive seen the cannon he used them on and they are PR)

It was either the stuff i had was unbeleivably weak or it must've been the brass fitting i tapped into it, because i went to the petrol station down the road, and used the air compressor down there, and seeing it was electronic, you could elect what pressure to pump into the tyre, i pumped all my wheels up to 30 psi, and then attached it to my gun, and as soon as i hooked it up, the endcaps started to expand and crack, so, thats where i got my theory from.

Either you didnt glue then properly e.g primer,1/4 turn,and applying primer first etc or you used DWV end caps, If you used DWV pipe with Pressure End Caps you would be fine.

yeah, ive tested dwv parts to 130 psi with no problems. And the end caps expanding and cracking is weird, you theory that tapping a brass fitting into it is probably the answer. I personnaly beleive its best to tap a brass or steel fitting into the part of the pvc fitting that the pipe slides into, so the brass or steel fitting is tapped into 2 layers of pvc.

I made sure I glued everything properly ,so they must not have been pressure rated, I asked the guy down at the plumbing center, and he didnt have a clue what I was talking about. he only knew what an endcap was, everything else i had to describe with a pen and paper ie: elbows, and the ball valve, i think he might have been there on work experience.

Killjoy,
I drilled a straight hole into the endcap and tapped the 15mm brass fitting into it, and it wasnt the best job in the world, but now ive seen the light and used thicker, pressure rated fittings and pipe from since then.

Funny story about this though. A long while ago my chemistry teacher made a spudgun. I don't know if it used dwv but I'm fairly certain it did because he went to a truck stop and filled it up with air, stepped away for a second and then heard a cracking sound. The next thing he knew there was pvc flying everywhere in the air.

If the pipe doesn't have a psi rating on it I would not use it for a pneumatic gun. Even some DWV sch 40 is pressure rated for example 2" Crestline DMV NSF is rated at 280 psi. If there is not a rating on it I would not exceed 30psi. If the pipe has a psi rating on it and the fittings have PW on them you'll be fine.

Yeah, thanks but we had all ready established that