I've always wondered why drain, waste, vent (DWV) requirements have horizontal angle requirements, but not vertical. What is to prevent me from using a series of 45 degree elbows and exceed 135 degrees vertically?
Here is a recent example that got me thinking: I needed to combine 90s in order to avoid a bump out in a corner wall (a single long sweep 90 was too wide to make the framing corner, so I combined one 90 flat against the framing going down towards the floor, and the other facing perpendicular to the wall to reach the main stack). It seems to me that a single horizontal long sweep 90 should be considered different from the situation described. But as I understand it, the vertical aspect is irrelevant and thus they are considered equal from a cleanout perspective because both are only 90 degrees horizontally.
I'm using a locally-modified 2021 UPC, in case that is useful to know.