The fire water tank refers to the fire-fighting facilities that provide water sources for the fire brigade during fire-fighting and rescue activities. On the one hand, it fills the fire-fighting water supply pipeline with water, saving the time for filling the pipeline after the fire-fighting water pump is turned on, and gaining time for extinguishing the fire. On the other hand, the pressurization and pressure stabilization system installed on the roof and the water tank can fill the water column of the fire water gun, which plays a decisive role in the success of extinguishing the initial fire.

1. For high-rise civil buildings, the height of the high-level fire water tank should be unfavorable to the hydrostatic pressure of the fire hydrant. When the building height does not exceed 100m, the hydrostatic pressure of the fire hydrant at the unfavorable point of the high-rise building should not be lower than 0.07MPa. When the building height exceeds 100m, The hydrostatic pressure of fire hydrants at unfavorable points of high-rise buildings should not be lower than 0.15MPa; when the above static pressure requirements cannot be met, pressurization facilities should be installed. The water storage capacity of high-level fire water tanks should meet: not less than 18m³ for Class I high-rise public buildings, not less than 12m³ for Class II high-rise public buildings and Class I high-rise residential buildings, and not less than 6m³ for Class II residential buildings. The capacity of the partitioned fire water tanks in the parallel connection mode of high-rise buildings shall be the same as that of the high-level fire water tanks.

2. For industrial buildings and multi-storey civil buildings, the high-level fire water tank should be installed at the high part of the building and store the fire water consumption for 10 minutes. When the indoor fire water consumption does not exceed 25L/s, the calculated fire water storage capacity of the water tank exceeds 12m³ , 12m³ can still be used; when the indoor fire-fighting water consumption exceeds 25L/s, and the calculated fire-fighting water storage capacity of the water tank exceeds 18m³, 18m³ can still be used.

3. For water tanks where fire-fighting water is used together with other water, technical measures should be taken to prevent fire-fighting water from being used for other purposes. Except for the series fire water supply system of high-rise buildings, the fire water supplied by the fire pump should not enter the high level water tank in case of fire. The production or domestic water pipe network should be used as its water inlet pipe.

4. When an automatic sprinkler system is installed in the building, the height of the high-level fire water tank should also meet the working pressure requirements of the nozzles at unfavorable points. If it cannot meet the requirements, pressure increasing (stabilizing) facilities should be installed.