How to drain the water pipes on the second floor of two ladders and two households with small high floors?

First, there is a once-and-for-all solution, which is to lead all water pipes out of the house like the first floor. Directly connected to the underground sewage pool, but the external wall should be taken over, depending on whether the property agrees or not. Second, the kitchen is used as an overflow pipe, that is, at the bottom of the sewer pipe in the kitchen, an overflow pipe is connected with a tee. When the pipeline on the external wall or the equipment platform is blocked, the sewage originally flowing back to the main pipeline of the pipeline on the second floor will be drawn out from this overflow pipe. Will not go back to the sink. If you are really worried, you can add a ball valve above the tee. Turn off the valve when you go out. Once water flows out of the overflow port, it is a warning signal of pipeline blockage, and you can immediately notify the property management to reduce your loss. However, you can also install a check valve in the kitchen, mainly to prevent water from flowing backwards. Note that the check valve must be pressed on the branch pipe, not on the main pipe. Third, buy a sealing flange for the backflow of toilet sewage. When installing the toilet, press the one-way rubber sealing ring under the toilet to prevent sewage from coming up. The price can also be cheap and the effect can be good. The disadvantage is that the spring seal will age after a long time, so it is recommended to replace it once every five years. Fourth, pipeline maintenance, regular use of pipeline dredging machine to wash a sewer. Generally, the oil in the inner wall of the new pipeline will flow to the pipeline inspection port on the first floor, and the property will be inspected quarterly or semi-annually. In short, if you can take over independently, you can take over independently, and if you can't, you can take over overflow pipe+check valve.