Probability Method Applied To Determine Water Supply Design Second Flow In Buildings Of Residents

The determination of water supply design second flow is one of the most important subject in building water supply and drainage and is the moist frequent question in designing. How to make the design flow accord with actual situation needs inquiring into. This paper presents a simple calculation formula based on probability method with studying the Hunter's method and Russian method deeply.The paper makes quantification about the two important factors influencing the designflow--frequency of fixture use p and water supply reliability P. The paper presents thatwater supply reliability does not make marked influence. So it is important to get a proper value frequency of fixture use. The value of frequency of use determined by water quota, the number of people and the number of fixtures is more convincing and reasonable in using different fixtures.According to the type of buildings, with many data ,we draw such conclusion that the equivalent of fixtures N and frequency of use p are interrelated to the design flow qg. We get the simulation formula ,with which an actual engineering is calculated.