According to the power and flow requirements of dialyzers, the power of each dialyzer is about 150 ~ 200 w, and the flow rate is about 10 ~ 20L/min. For 30 dialyzers, the total power is calculated as the sum of the power of 30 dialyzers, that is, 30× (150 ~ 200 W). According to the calculation results, 30 dialysis machines need to be equipped with water machines with total power of 4500-6000 w, and the flow rate of purified water should be between 450-600 l/min. This kind of water machine can meet the water demand of 30 dialysis machines and ensure the water quality and flow rate meet the requirements during dialysis.