Water supply equipment plays a crucial role in addressing daily water pressure issues. It is widely used in high-rise residential complexes, schools, factories, hotels, inns, and rural areas, among others. The choice of water supply equipment varies according to customer needs, and each manufacturer may have different standards for categorizing such equipment.

I believe many of you are familiar with the concept of secondary water supply! The tap water we use in our daily lives is transported to our homes through pipes. Water transported through pipes is generally under pressure; when tap water leaves the waterworks, it is pressurized to 0.38 MPa, which can lift the water to a height of 38 meters. Therefore, theoretically, for buildings below this height, the water from the waterworks can directly flow into residents' homes through the pipes.

However, some terrains are different, and as the distance of the tap water in the pipeline increases, the resistance also increases, and the achievable height decreases accordingly. Therefore, this 38-meter height line is not parallel to the ground. However, some buildings have floors too high, which can lead to insufficient water pressure and the inability to supply water to higher floors. As a result, many high-rise buildings activate secondary water supply. From which floor does the secondary water supply for high-rise buildings start?

Utilize the existing pressure in the potable water pipeline, adding only as much pressure as needed. The equipment stops working once the water meets the required quality, achieving a 50% reduction in pressure. For instance, in a residential complex with 6 floors, during peak water usage, the potable water can reach up to the 4th floor, while during off-peak usage, it can reach the 6th floor. The variable frequency constant pressure water supply equipment boosts pressure to the 5-6th floors during peak usage and enters sleep mode during off-peak. Power outages can restore normal water pressure, consuming less energy and reducing operating costs, making it economical and saving daily electricity expenses.