1. A group of fire pump unit, the water suction pipe should not be less than two, when one of the damaged or repair, the remaining water absorption pipe should still be able to design through all the fire water supply;
2. Fire pump unit suction pipe arrangement should avoid the formation of air bag;
3. A set of fire pump units should be no less than two of the water mains and fire water supply pipe network connection, when one of the water pipeline maintenance, the rest of the water pipe should still be able to pass all the fire water supply design flow;
4. Fire pump suction submergence depth should meet the fire pump in the safe operation of the lowest water level, water pipe bell in the fire pool minimum effective water submergence depth should be according to the suction pipe horn of flow velocity and hydraulic conditions determined, but shall not be less than 600mm. When the swirl device for preventing submergence depth should not be less than 200mm;
5. Fire pump unit should be set on the water pipe of the valve or the valve with a self locking device, but when the dark rod valve should be set to open the scale and signs; when the diameter of more than DN300, the electric valve should be set;
6. Fire pump outlet pipe should be set the check valve, Ming bar gate valve; when the valve should be provided with a self-locking device; when the pipe diameter more than DN300, should set the electric valve;
7. Fire pump unit diameter is less than DN250, the flow rate should be 1.0m/s~1.2m/s; diameter is greater than DN250, should be 1.2m/s~1.6m/s;
8. The fire pump outlet pipe diameter is less than DN250, the flow should be for 1.5m/s~2.0m/s; diameter greater than DN250, suitable for 2.0m/s~2.5m/s;
9. Water wells arrangement should meet well the water flow in the downstream, the uniform velocity and no vortex, and should facilitate the installation and construction;
10. Fire pump unit suction pipe, water pipe through the wall, should use waterproof casing;
11. The water suction pipe of the fire pump unit should be used in the fire water tank, and the flexible pipe should be set on the water suction pipe of the pump unit, and the pipe diameter should not be greater than DN150.
