From the working principle, the check valve is connected in series with the water meter. There seems to be no difference between the front and the back of the installation meter, which can prevent the backflow of tap water to a certain extent and avoid metering disputes. However, if we analyze this problem carefully, we will find that it is better for users to install it in front of the table. (The direction of the supervisor network is in front of the table, and the direction of the user is behind the table). It is installed in front of the water meter, which completely eliminates the connection between the water meter and the external pipe network. Even if the tap water pressure in the user's home will have corresponding pressure fluctuations, it is still stable compared to the external pipe network, which greatly protects the interests of the user. And if it is installed behind the water meter, it means that the water meter and the external pipe network are not separated. Although the pipeline from the water meter to the check valve will not be too long, when there is always a certain length, this length will also be affected by the water pressure of the external network. In the case of fluctuations, the phenomenon of backflow occurs, which will affect the measurement of the water meter to some extent. Therefore, it is necessary to install a check valve on the household water meter, and it should also be installed in front of the water meter.
