SpudFiles

dapallox1 wrote:I just noticed on a lot of the pvc pipe i have, it says NSF-dwv AND NSF-pw ... some have a psi rating, and others don't... so... What are safe to use?

If it has both, and a pressure rating it's safe. I'm not sure about it though, if it doesn't list a PSI...Does it list a bar pressure?

Bar pressure? What's that?

http://en.wikipedia.org/wiki/Bar_%28unit%29 explains it.

Umm, lol, okay, that didn't really explain it to me, but thanks anyways. But back to the piston valve, should i just do a 2", and then a 4" later on? Oh good is a two inch, e.g. How far can I shoot ca golfball with two 4" x 2 1/2' chambers and a 2" barrel?

Look at this valve and build one like it (maybe scale it up a bit): http://www.spudfiles.com/forums/c19os-1 ... 10494.html I built one like it and it works great. My slayer valve wasn't worth using for the unreliabilty that came with it. Even Gorts valves break down alot and need to be fixed.

If it has a pressure rating well above what you are using, use it. The pipes at my hardware store sometimes have DWV on them, but ALL are pressure rated to at least 280 psi.

Yeah, I figured that

@Original Unknown

My bad, I mixed up two links in my favorites listing and combined them. In other news I emailed a friend your Mauler thread , so I get to fix that as well. I edited the original post. Credit where it due.

@dapallox

I would start with a 2 inch. They are easier to get a hold of and work with at first and you aren't the 20 bucks for the tee if you go farking everything up.

As for the 6 inch I have been working on it in my spare time. I am using a 6 inch schedule 80 tee for extra strength. Porting 4 inches for the barrel and piloting using a 2 inch sprinkler I still need to find. My problem has been the piston and building to withstand the force around the sides of the cylinder. When it is finished you can bet you will see it on here.

If the pipe says NSF-pw, or has a suitable pressure limit printed on it, it is OK to use in a compressed air gun.

The only reason it has the NSF-dwv rating on it is because that is a lower rating and the pipe can be used for that purpose as well. In general, all NSF-pw can also be used as NSF-dwv. The opposite is not true.

NSF = National Sanitation Foundation (international organization that develops standards for the plumbing and other industries)
pw = potable water (a pressurized water application)
dwv = drain, waste, vent (a non pressure application)

A "bar" rating is the same as a PSI rating, just on a different scale. 1 bar = 14.5 PSI ~ 1 ATM

Edit: Williamfeldmann pointed out to me the "pw"= potable water. The spec for potable water, ANSI/NSF 61, apparently includes the pressure rating requirements. Anyone know where there is a copy of ANSI/NSF 61? A google search turned up a gazillion links but I didn't find a link to the actual spec. Searching the NSF site for "NSF-pw" or "ANSI/NSF 61" times out.

NSF-pw stuff complies to the NSF Standard 14 and Standard 61. I believe 61 is mostly health requirements, and 14 is more of the physical and performance requirements. I haven't been able to find the standards either. I think I may check out if my university library has the book. Looks like they do, but it also looks like it is from '79.

This is another good valve, just wrap the endcap in tape to get a better fit: http://www.spudfiles.com/forums/pvcmast ... 10086.html