NFS-DW? is it safe.

[MrCrowley]

The best thing 8ton can do is post what is written on the pipe so we can look up the standards. While non-pressure rated DWV can be made of cell core, I'm pretty sure that the pressure rated DWV is not made of cell core.

If it has 230PSI on it, there is no reason you can't use it up to 120PSI like NSF-PW pipe. If it has a slightly worse structural properties than NSF-PW meaning it can't take too many knocks; I would suggest going with ABS if you plan on knocking/dropping your PVC chamber, regardless of whether it is PW or DWV with a rating.

[jimmy101]

If it is 3" NSF-DWV Sch40 PVC with a 230PSI pressure rating on it, yes I would use it. Why not? Matty, you do understand that it has a pressure rating, i.e. that it is rated for pressure; specifically 230PSI.

The DWV part is irrelevant if it has a pressure rating. If I recall correctly, it just means that it can be used for Drain, Waste, Vent applications. Perhaps there's a specific standard that makes DWV pipe favourable over PW pipe in certain applications but I'm unsure of what that standard could be.

This isn't run-of-the-mill DWV pipe, it's DWV pipe with a pressure rating. You're thinking of the typical DWV pipe without a rating that we criticize often.

Pressure rated or not, its garbage. dwv, like you said, is used for drain waste venting and its CELL CORE pvc and breaks easily. 9 out of 10 plumbers wont even use it because it constantly breaks and its not worth the hassle in replacing it. If you hold a decent size piece 4 to 5 feet, over your head and drop it on a hard surface its going to break. I would use it for a barrel but thats it. Definatly not a chamber. If you wanna use it, feel free, but I wouldnt. Go to a plumbing supply store and get the good stuff!!

Damn, how many times do we have to explain this.

1. The presence of "DWV" on a pipe has absolutely zero meaning! All pipe with the proper dimensions can be used for DWV. Zillion dollar pipe rated to a zillion PSI might still be labeled "DWV" since it can be used for that purpose. ALL PRESSURE RATED PIPE, with proper dimensions, is rated DWV as well.

2. What matters is the pressure rating. If the pipe says it is rated to 220 PSI then it is pressure rated to that.

3. True "cell core" pipe will only have the DWV rating and not a pressure rating. Indeed, cell core usually says quite specifically "not rated for pressure".

I've got all kinds of pipe with both the DWV and PWS ("potable water system", by code a pressurized water system) labels. The two labels do not refer to the same thing. A pipe can be +DWV +PWS, +DWV -PWS, -DWV +PWS or -DWV -PWS. Presence of one of the labels, by itself, tells you nothing about the possible presence or absence of the other label.