Rules on using 90 deg. el in dwv

section 706.3 IPC dictates what are acceptable changes in direction. I've got some questions as there is conflicting information out there.

Can a 90 be usd? Or do I need to use several fittings?

I've got everything cut and strapped. Just need to glue it all up. Will post some pics before gluing.

down or sideways??

are you dropping down with the 90??

or are you turning sideways??

dropping straight down is no big deal, crap falls just fine.

if you are making a horisontal turn it would be best to use a coulple of

street 45s to make that bend or something large will decide to stpo up at that elbow. some long sweep 45s are best for a horizontal turn.

Its actually the dreaded rolling offset....

I cant find my pipefitters handbook, it had this very problem in there....

I remember its something about adding the square roots of the travel and the run...depending on whether your doing a 45 or 30 or 22 offset.

I've been out of the trade so long, it bugs me becuase I used to be able to do this in my sleep. And then the next day drill 3,000 hilti anchors to hang it all....

IPC Table 707.3

Quarter bend may be used:

Horizontal to vertical

Vertical to horizontal <only on a 2" and smaller fixture drain>

Horizontal to horizontal <only on a 2" and smaller fixture drain>

elbow

A standard quarter bend, (elbow), can be used to transition from a horizontal line down into a vertical one. Every place else a long radius quarter bend is required. It is the same as two 1/8 bends (45'sa).