The buried depth of the pipeline should be determined according to the freezing degree, external load and other pipeline crossing factors. Under normal circumstances, the buried depth can be 0.2 meters below the freezing line, and the following conditions are met: When the diameter of the pipe is greater than 100mm, the minimum buried depth of the pipe top is 1.20 meters.

The bottom width of the design trench is generally 0.5m plus the outer diameter of the pipe. According to the soil condition, the excavation slope (i) is determined and the trench section view is drawn.

Ductile iron pipe and other pipe, uniform flow along the head loss is also hf=λ/dv2/2g, the difference is only "λ" (hydraulic friction coefficient), that is, the head loss can be calculated according to the local resistance loss of the original cast iron pipe. Ductile iron pipe and other pipe, uniform flow along the head loss is also hf=λ/dv2/2g, the difference is only "λ" (hydraulic friction coefficient), that is, the head loss can be calculated according to the local resistance loss of the original cast iron pipe.

The appearance of ductile iron pipe provides a new type of water supply material with excellent properties in our country. In order to better use ductile iron pipe in engineering, design and construction personnel should be familiar with the characteristics of ductile iron pipe, constantly find problems and solve them, so that the design is more reasonable, the construction is more standardized, so that the new pipe in the water supply engineering play a greater role.