Centrifugal spheroidal cast iron pipes are produced by casting iron water with a No. 18 or higher grade, added with spheroidizing agent, and then cast at high speed through a centrifugal spheroidal cast iron machine. These pipes are referred to as "Ductile Cast Iron Pipes," abbreviated as Ductile Iron Pipes, Spheroidal Iron Pipes, and Spheroidal Cast Iron Pipes, etc. They are primarily used for the conveyance of tap water and are an ideal material choice for water pipelines.

In many regions across our country, ductile iron pipes are used for medium and small diameter piping connections, employing socket-and-spigot or flanged joint methods; ductile iron allows for limited bending angles and must possess superior seismic resistance and sealing properties.

The main components of ductile iron pipes include carbon, silicon, manganese, sulfur, phosphorus, and magnesium, among others.

Standard of Execution: International Standard ISO2531:1998 and National Standard GB13295-2008

Ductile Cast Iron Pipes, commonly referred to as Ductile Iron Pipes, Ductile Cast Iron Tube, or simply Ductile Iron Tube, are pipes produced by adding spheroidizing agents to casting iron water with a grade of 18 or higher, and then cast at high speed through a centrifugal ductile iron casting machine.

Ductile iron pipes are a type of cast iron pipe. The quality requirements call for the spheroidizing grade of the cast iron pipe to be controlled at 1-3 levels (spheroidizing rate > 80%), thereby significantly improving the material's mechanical properties, combining the essence of iron with the performance of steel. After annealing, the microstructure of the ductile iron pipe consists of ferrite with a small amount of spheroidite, offering excellent mechanical properties, corrosion resistance, ductility, and sealing performance. They are easy to install and are primarily used for municipal, industrial, and mining enterprises for water supply, gas transmission, and oil transportation.

On the ferrite and spheroidite matrix, a certain number of spherical graphite are distributed. The ratio of ferrite to spheroidite in the matrix varies depending on the nominal diameter and the required elongation. For small diameters, the spheroidite ratio is generally not more than 20%, while for large diameters, it is usually controlled around 25%.

Mechanical properties

Minimum tensile strength: 420 MPa, minimum yield strength: 300 MPa, minimum elongation: 7%

Bore Size: DN80 - DN1600

Performance

Ductile iron pipes are a type of cast iron, an alloy of iron, carbon, and silicon. In ductile iron, the graphite exists in a spherical form, typically ranging in size from 6-7 grades. The quality requirement for the spheroidizing grade of the cast pipes is controlled at 1-3 grades (spheroidizing rate ≥80%), thereby significantly improving the material's mechanical properties, combining the nature of iron with the performance of steel. After annealing, the microstructure of the ductile iron pipes consists of ferrite with a small amount of pearlite, and they exhibit good mechanical properties.

Ductile iron pipes, primarily known as centrifugal ductile iron pipes, possess the essence of iron and the properties of steel. They offer excellent corrosion resistance, good ductility, superior sealing performance, easy installation, and are mainly used for municipal and industrial water supply, gas transmission, and oil transportation. They are the preferred choice for water supply pipes, offering high cost-performance. Compared to PE pipes, ductile iron pipes are simpler and quicker to install, with better internal and external bearing pressure after installation. In terms of tightness and corrosion resistance, the installed ductile iron pipes have better tightness and can enhance their corrosion resistance through various protective measures. From a hydraulic performance perspective, since the ductile iron pipe specifications generally refer to the inner diameter while PE pipe specifications generally refer to the outer diameter, the ductile iron pipes can achieve greater flow rates under the same specifications. In terms of overall installation and maintenance costs, ductile iron pipes provide a more superior cost-performance ratio. Zinc spraying on the inner wall, cement sand slurry for corrosion protection, and other materials are used.