Basic points for selecting a water pump

The selection of pumps is crucial in building water supply and drainage design. The selection of water supply pumps, sewage pumps, and fire pumps should comprehensively consider factors such as the characteristics of each system, pump parameters, and maintenance.
1 Water Supply Design
　　1) Brief description of water sources (including self-provided water sources and municipal water supply networks).
　　2) Estimation of water consumption and heat consumption: total water consumption (highest daily, maximum hourly), hot water design hourly heat consumption, fire water consumption.
　　3) Water supply system: Brief description of the system's water supply method.
　　4) Fire protection system: Brief description of the type and water supply method of the fire protection system.
　　5) Hot water system: Brief description of the heat source, supply range, and supply method.
　　6) Recycled water system: Brief description of the design basis and treatment method.
　　7) Circulating cooling water, reused water, and other water and energy saving measures adopted.
　　8) Drinking water purification system: Brief description of the design basis and treatment method, etc.
2 Drainage Design
　　1) Drainage system, discharge outlets for sewage, wastewater, and rainwater.
　　2) Estimation of sewage and wastewater discharge, rainwater volume, and recurrence period parameters, etc.
　　3) Description of the drainage system and comprehensive utilization.
　　4) Treatment methods for sewage and wastewater.

The municipal water supply network uses a dual-loop network to supply water to the underground domestic water pool. Pumps lift water to the annex and main building roof tanks, then gravity flows to each water point. The start and stop of the pumps are controlled by a level controller. Using this upward and downward water supply method, the roof tank plays an intermediate adjustment role. When the pump starts running, the Q～H value is relatively constant, and the Q～H value does not change with the amount of water used at the water point. In the design, the selection of the pump only needs to meet the calculated Q～H value. However, it should be noted that the Q～H value of the selected pump should not be much larger than the design calculated Q～H value, generally it is advisable to control it to be about 5% larger than the design calculated Q～H value. According to the above principles, in our design, the water pumps for the annex and main building water supply systems are selected as 65DL32—15×3 and 80DL50—20×5 type pumps.