Connecting to City Sewer Main

[jaxbldginspector]

The City made a new tap and extended a 4" PVC lateral from the center of the street to my property line. Their main is about 3 or 4' deep. I only have to run my new 4" sewer line approximately 10 to 15' to connect to theirs.
My sewer pipe is about 12" deep coming from under the house. Do I use two 45's to turn down to tie onto their line? I am using the 1/4" per foot method for my fall.

Thanks for your help you guys are great!

[Bob NH]

Skip the 45s altogether and use more grade for the sewer. You can get enough bend at each joint to line things up. If you need more joints to male the angles you can cut the pipes to 5 ft lengths and use couplings but you can probably just make the connections with standard lengths of pipe.

Contrary to some "old-plumbers tales" a steep grade on an individual service will not be a problem.

There are often maximum grades on municipal sewers to avoid high velocity at manholes and erosion that can occur in concrete pipes but there is not enough flow in yours to matter.

I have seen 45 degree slopes in internal plumbing and it isn't a problem.

[hj]

Angling the pipe works most times, but 10' is too short of a distance to do it without serious cocking at the two ends. use 1/8 bends.

[Herk]

I concur. Two eighth bends. Or, two sixteenth bends - even easier to get through.