5.Pipe network layout shown by category (the type for the last time, for reference next time type) is the basic type of piping system, the designer should be based on system size, building height and other design factors
 6.The pipe selected in line with relevant provisions of existing national standards, and should be "in drinking water safety equipment and protective materials evaluation criteria"GB/T17219 requirements
 7.The highest point of the network set up automatic exhaust valve, exhaust valve should be provided at the filter bacteria, dust-proof device.
 2. circular flow calculation
 Meet the "design of building water supply"GB50015-2003 of the relevant provisions of the cycle of not more than 12h, in which time the cycle time of not more than 4h, full-cycle time of less than 12h.
 Circulating pump selection calculations: direct drinking water system, circulating water pump sizing should follow the "Technical Specification for direct drinking water system,"CJJ 110-2006 relevant provisions.
 Timed Loop, the loop flow can be calculated as follows:
q_x=V/T₁ 

 qx = circulating flow (L / h)

 V = closed circulation loop for reference by the total volume of return water system (L), including the supply and return pipe network and water tank volume;

 T1 = cycle time (h), not more than 4h.

 Water supply and return water pipeline speed should be consistent with the provisions of Table 2.

 Table 2 for the return water pipe flow velocity should meet the following requirements