Floor drain back flow
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.
There are two types of back flow checks that I know of. One is a swinging flap that is supposed to close if/when water rises in the drain. These don't really work well because over time dust and lint collect one the gate and when water rises slowly, they don't close. The second type has a ball that floats up and closes the pipe. These don't seem to be affected by the accumulation of lint and work quite well.
Backwater valves. The ball type are definitely the ones to go with. The one's I've seen "push" the sanitary a little lower by design so if pipe invert is an issue they may not be practical.
I have installed one of these in my basement floor drain.
Let's the water out and stops water coming in.