Calculating the design flow rate of water supply pipelines is a core step in water supply system design, used to determine the maximum water flow demand within the pipeline. The design flow rate for domestic water supply pipelines within buildings needs to reflect the randomness of water usage, commonly using the probability method and the simultaneous water usage percentage method. The probability method is suitable for residential buildings, with the design flow rate calculated using a probability model. The simultaneous water usage percentage method is suitable for public buildings, with the design flow rate calculated based on the proportion of simultaneous use of the maximum hourly water consumption.
The design flow rate of municipal water supply networks is usually based on the highest daily peak hourly water consumption.
Fire protection water supply systems require independent calculation of the design flow rate, based on the maximum fire protection water consumption simultaneously acting at the most unfavorable fire point.
