I'm trying to install a Flood Guard floor drain for my floor drain in the basement. We've had 2 sewer backups and are trying to prevent any further issues. The smallest these come are 2" diameter. my pipe seems to be about a 1 3/4" because it is just not quite fitting. Any suggestions for filing/routing out the cast iron pipe to get it to a 2"? I've tried a heavy duty hand file from the local hardware store with no luck. Thanks!

If that is a 1 3/4" cast iron pipe inside diameter pipe you will never get the flood guard to fit inside. You could strat to chisel out the pipe but you might get in over your head not knowing where it connects to the next drain. You could screw in a 1 3/4" galvanized pipe a few feet tall to act as a stand pipe. This will prevent backup but unfortunately blocks that drain.

Since you can't enlarge the opening in the floor drain would it be possible to take a razor knife and shave the check valves,(see image) down to size? Just a thought.
Regards, Tom

You should make sure the four screws that are on the top of the valve are backed off. It will release the outward pressure on the rubber seal. That rubber seal will retract then you can slide it in and then retighten the screws expanding the rubber to make a tight seal. Brock