I'm replacing 3”copper drain pipe with 3” PVC. The horizontal run is appx. five feet (toilets,sinks) then transitions to a vertical run, then another horizontal to the sewer. I was originally going to use 90 degree long throw bends at both transition points, then I was told a normal throw/bend is used at the horizontal to vertical points. Some research indicated this was correct, while others indicated that either a normal or long throw can be used. It appears that the long throw is to be used at the vertical to horizontal. My reason for the long throw at both locations is because of the waste solids. The copper was recycled so I don't know what type of bend was used originally.

So, at the horizontal to vertical point, is either bend acceptable? Is this something that is code specific or just a plumbing practice? Any concerns relating to flow with a normal throw/bend in this application?

Avoid using an elbow on PVC for a drain.

Ballen.. I agree but I'm not using an elbow or a vent ell. I shouldn't have used the 90 degree reference. What I'm referring to are bends or throws which have a large radius, one is normal/standard (?) and the other is the long throw.

On our rough ins we use 90's to transition from vertical to horizontal and from horizontal to vertical. On horizontal runs we use two ,45 degree bends or a long sweep ell. Good luck, Tom