Ductile Iron Pipe Instructions

In 1947, H.Morrogh of the United Kingdom found that when cerium was added to hypereutectic gray cast iron to a content of more than 0.02wt%, graphite was spherical. In 1948, A. P.Ganganebin et al. of the United States pointed out that when magnesium was added to cast iron and then inoculated with ferrosilicon, spherical graphite was obtained when the residual magnesium content was greater than 0.04wt%. Since then, large-scale industrial production of ductile iron has begun. The history of the use of ductile iron pipes can be traced back to the 21.14km water pipeline from the Seine River to Versailles in the suburbs of Paris in 1668. After 300 years, except for the maintenance and replacement of some pipes and joints, the main body is still in use today.

Compilation of this paragraph The current situation and prospects of ductile iron pipes in my country. my country's ductile iron pipe industry started in the early 1990s and developed rapidly with the strong support of the China Urban Water Supply Association. After nearly 20 years of practical use, its practicality has been widely recognized by the water supply industry. In 2008, the domestic annual output reached 2.2 million tons, which is 11 times that of 1990. Because my country is a country with scarce water resources, there are more than 600 water-deficient cities and more than 200 cities with severe water shortages. The water supply and water-saving business is in the ascendant, and ductile iron pipes have broad development prospects.

Advantages: In medium and low pressure pipe networks, ductile iron pipes have reliable operation, low breakage rate, convenient and fast construction and maintenance, and excellent anti-corrosion performance.

Disadvantages: In high-pressure pipe networks, it is generally not used and has low pressure resistance. Because the pipe body is relatively bulky, machinery must be used during installation.

my country produces 1.5 million tons of ductile iron pipes and 50,000 tons of matching pipe fittings annually. The products have been successfully used in the construction of national and local key projects such as the Taiyuan Yellow River Diversion Project, the Lanzhou Yellow River Diversion Project, the Nanjing Jiangning Water Supply Project, the Xi'an Urban Water Environment Management Phase II Project, and the Baoji Urban Emergency Water Supply Project. With excellent quality and good service, it has won the general recognition of users and is currently recognized as a leading enterprise in the industry.

In addition, Jincheng City has always been a well-known forging town in China.

Compilation of construction and installation points in this section:

1. Trench excavation

The bottom width of the trench should be calculated according to the following formula: B=D1+2(b1+b2)

Where: B—excavation width of the bottom of the pipeline trench (mm) D1—outer edge width of the pipeline structure (mm) b1—working surface width on one side of the pipeline (mm) b2—support width on one side of the pipeline (mm)

2. Trench support. The design is based on factors such as trench soil, groundwater, slot section, load conditions, etc. It is required to be firm and reliable to prevent collapse, and the support must not hinder the laying and stabilization of the pipe.

3. T-type interface pipes should be equipped with piers at the vertical or horizontal bends. The size of the pier should be determined by calculation based on factors such as pipe diameter, turning angle, and working pressure.

4. When transporting drinking water, the pipeline should not pass through the toxic pollution area. If it is necessary to pass through, protective measures should be taken.

5. All ductile iron pipelines with socket connections must be equipped with piers after calculation. See the National Building Standard Design Atlas 03SS505 "Flexible Interface Water Supply Pipeline Piers".

6. The external anti-corrosion coating of ductile iron pipes should be selected according to the soil conditions of the pipe laying site. Galvanized and epoxy asphalt coating or higher requirements of coating.

7. After the pipeline is installed and the pressure test is qualified, it is advisable to flush it with low chloride ion water and disinfect it with 0.03% potassium permanganate aqueous solution.