The check valve is installed in the water supply line, and the drainage system should not be equipped with a check valve, so do not install a check valve in the toilet sewer in order to prevent water return. Because the return valve is used in the pressure pipeline, it relies on the pressure of the water flow to control the opening and closing to prevent backflow. The drain pipe of the bathroom belongs to the non-pressure pipe, and the check valve cannot be opened by the water flow, and if it is installed, it will only be blocked there, without any meaning.
< br >
In fact, there is no need to install the toilet check valve, first of all, the water pipe is under pressure, the water in the toilet tank is not under pressure, and second, if the tap water is stopped, the water needs to be released first and then eaten. Finally, the water in the toilet tank will not flow back to the water pipe, because the water inlet of the toilet tank is higher than the liquid level of the tank.
There's no need! The toilet check valve is mainly to prevent the water in the toilet tank from flowing back into the tap water pipe, but this situation almost never happens in real life. First, there is pressure in the water pipe, and there is no pressure in the toilet tank, because there is a pressure difference, so there is basically no reflux. Second, the water inlet of the toilet tank is higher than the liquid level of the water tank, so the water in the tank can not flow back into the water pipe through the water inlet.