1. The cold and hot water outlets of the drainage pipes must be level, generally the left side is hot and the right side is cool, and the piping should be laid horizontally and straight. The layout should be safe and reasonable. The position of the pipe clamp and the slope of the pipe shall meet the requirements of the specification. All types of valves should be installed in the correct position and level for easy use and maintenance. 2. The water inlet should be equipped with an indoor main valve. Before installation, check whether the water pipes and connecting accessories are damaged or cracked. 3. The distance between the water meter and the valve from the wall should be appropriate, and it should be convenient for use and maintenance.