Want to replace a floor drain in a basement since already doing some concrete work. Looks like just a 2" line.
I know there will be a P trap in the line. But is there a backflow valve.
I have used check valves for other things. But it seems like a good idea to have one here so if main line ever backs up would not flood basement. But how could this even work since the floor drain would have so little pressure to open valve. If the flapper type is that weak it does not seem like it could work well.