I have my whole house sewage line coming into a pit bought at home depot (flotec). Inlet is 4" CI that has two full baths and one kitchen w/ dishwasher flowing through it. On the other side of the pit is a 4" CI that has a full bath from the basement coming into it.
I originally used a Goulds 1/3 hp pump piped up from the pit with 2" PVC that rises about 11'. Check valve located just below the lid in the pit. This 2" line san tees into a 3" line w/ cleanout that runs another 11' pitched. There it elbows downward 3' where it san tees w/ cleanout horizontally to a PVC house trap and exits the building to the cesspool.

**This was done b/c the original sewar line ran across the basement wall midway. An outside entrance to the basement as well as a full size window were added and the pipe was in the way.***

The gould pump would work for about 7 "pumps" and then would trip on overload. After three overflows from the pit, I went to home depot and purchased a cast itron flotec pump piped the same away as above. The pit is vented and ties into the house vent. The pump runs on ints own 15amp breaker.

Here are my questions?
* I have a bang when the pump turns off, I've put a banded no hub clamp along the 11' rise and placed foam under the 1st san tee and used straping and then removed it along the horizontal run. Bang is still there. Any suggestions?
**In the event of an overflow, can I install a check valve in the 4" CI that comes from the basement bathroom as this was a mess when it did over flow.