Is NSF-DWV PVC toxic?

[Greenmountain]

I am attempting to build a flow sleeve for a submersible pump that will be used for drinking water. I picked up some 6" PVC fittings (made by spears usa) which are marked "NSF-DWV" (the pipe is rated "NSF-pw").
The people at the store promised the fittings were fine for drinking water, but I'm not 100% convinced.
Is the "DWV" rating more about pressure, or is it actually a different PVC formulation which could potentially leach toxins? I called spears and they were not able to give a coherent answer...

 

[Reach4]

That is a pretty big flow sleeve for a 4 inch pump. 4 inch PVC SDR sewer drain pipe (often green) would be fine for a "4 inch" pump (which is 3.9 inches or less). PVC 4 inch schedule 4o would be OK. http://www.deanbennett.com/flow-inducer-sleeve.htm Your 6 inch should still do the job of giving good enough cooling.

The DWV rating for PVC is about pressure.

 

[Sponsor]

 

[Greenmountain]

So "nsf-dwv" PVC is safe for use with drinking water then, so long as it's not used in a pressurized system?

yes, 6" does seem big... but, my pump is rated at 16gpm and I was concerned about going with 4" because there would be a very narrow space b/t the inside of the pipe and the outside of the pump. It would require the water to flow at pretty high velocity... I'm not sure if that would be a problem or not? Wouldn't limiting the flow of water into the pump make it work harder? Isn't that sort of a trade off for more efficient cooling?

The info with the pump says 13gpm is required for cooling with a 4" pump in a 6" casing, so I figured with a 16gpm pump it should be ok, right? Although I don't know what the actual gpm will be with all the other variables...
It also doesn't say anything about water temp. Mine is pretty cold most of the year. Probably peaks around 55-60F and gets down to almost freezing.

The pump I am replacing had no flow sleeve, and it did have problems with overheating (I'm assuming that anyway, as it would shut itself off if run for too long), so I want to get this right.

 

[Reach4]

yes, 6" does seem big... but, my pump is rated at 16gpm and I was concerned about going with 4" because there would be a very narrow space b/t the inside of the pipe and the outside of the pump. It would require the water to flow at pretty high velocity... I'm not sure if that would be a problem or not? Wouldn't limiting the flow of water into the pump make it work harder? Isn't that sort of a trade off for more efficient cooling?

You make good sense.

http://www.harvel.com/technical-support-center/product-specifications/pvc-pipe-sdr-series In theory there is 5 inch nominal pipe and 4 inch SDR 26 , 32.5, and 41 pipe, but I have no clue where to get a piece.

Valveman has a lot of experience with flow inducers.

 

[hj]

You NEVER limit the flow INTO a pump, unless you want to destroy it.

 

[Valveman]

4" flow inducer is good up to 60 gpm. Better cooling for the motor too. Are you sure the pump is running continuously when using water for long periods? Because cycling on and off is more likely to cause overheating.