2) there should be 8-10 times of the nominal diameter straight pipe at the front end of the screw wing type water meter, and there should be no less than 300 mm straight pipe before and after other types of water meters. 

3) rotor type water meter and vertical screw wing type water meter shall be installed horizontally; horizontal screw wing type and positive displacement type water meter can be installed horizontally, obliquely or vertically according to the actual situation; when installed vertically, the flow direction must be from bottom to top. 

4) for the water supply system integrating life, production and fire protection, if there is only one inlet pipe, a bypass pipe shall be installed around the water meter.

5) maintenance valves shall be installed at the front and back of the water meter and on the bypass pipe, and drain devices shall be installed at the water meter and the valves behind the meter. In order to reduce the head loss and ensure the straight flow of water in the pipe in front of the meter, the gate valve should be used for the maintenance valve in front of the meter. For the household water meter in the house, the maintenance valve behind the meter and the special drain device may not be provided. 

6) the direction of water meter shall be consistent with its type. 

7) when the water meter may reverse, affect the metering and damage the water meter, a check valve shall be set behind the water meter. 

8) the water meter well shall be protected from inundation and rainwater. 

9) the installation requirements of hot and cold water meters are basically the same except for different working temperatures. The maximum working temperature of the hot water meter is 110 ℃. If the water meter is installed in front of the boiler or heat exchanger, a check valve shall be set behind the water meter to prevent backflow. 

10) there are two ways to install the remote water meter: the installation of the remote water meter which only plays the role of outdoor meter reading is relatively simple, as long as the water meter output system is connected with the data display device (repeater) installed outdoors; the other way is to connect all the remote water meters of the whole building or the whole community to the community management department through the repeater and network controller, and through the terminal Unified management of equipment.