I am planning to replace the cast iron sewer line in the basement floor. The house is older and the drainage lines to the cast clean out are 3 inch copper adapted to the cast at the clean out unit.

I see no problem connecting the 3 inch copper to 3 inch ABS before the new clean out, and connecting the ABS down the line to the old Cast. I presume this should be done with sleeve connectors.

I would like to install a new floor drain and P trap and would like to know the correct positioning of these.

Currently the old existing cast floor drain (plugged solid) is Y'd away from the sewer line and I would expect there is a P trap somewhere underneath.

I would also be installing a Backwater Valve at the same time.

:cool: :cool:

A floor drain has a built in trap. Any floor drain will do. To check out floor drain flood protectors,(see image) click on; http://www.plumbingsupply.com/floodguard.html
Good luck, Tom

Floor drain info was helpful--tks.
However I would like to know the proper sequence of installation of the new ABS adapting to cast sewer line and the placement of floor drain and backwater valve, and if a P Trap is required.

Also I have to adapt the newly installed ABS cleanout to the older 3 inch copper stack.

Any info would be helpful.

Tks. Dave.

"I would like to know the proper sequence of installation of the new ABS adapting to cast sewer line and the placement of floor drain and backwater valve, and if a P Trap is required.
Also I have to adapt the newly installed ABS cleanout to the older 3 inch copper stack."

Now I'm confused. Please explain in detail exactly what cast iron fitting you wish to come off to convert to a ABS what? Pipe? Floor drain? (As I've stated, floor drains have built in traps).
As for the cleanout you haven't given me any details to work with. Is the connection vertical? Horizontal? In the wall? Floor? Connect what to what. Hub to bald end? Hub to hub? Sorry, I simply don't have enough to work with here. Regards, Tom

OK here goes -- this is how the system runs at present. The 3 inch vertical stack is copper. It is approximately 5 feet high and is connected at the base to a cast clean out
Fitting. Approximately 5 feet downstream from this is a cast Y (installed horizontal and an old cast floor drain is located here. ( all plugged up). Not sure if there is a P trap in this connection or not Then the cast pipe (3 inch) continues on out to the sewer. I wish to install ABS connecting to the 3 inch copper stack, install a ABS clean out Y a floor drain and a Backwater valve--then connect to the old 3 inch cast. Dave.