Ductile Iron Pipe Class K8 Publication

This type of water pipe is mainly made of graphite, which exists in a spherical form with a size grade of 6-7. Its manufacturing materials have been greatly improved, possessing the nature of iron and the performance of steel. Class K ductile iron pipes are classified by their wall thickness, including Class K7, Class K8, and Class K9 ductile iron pipes. Among them, the wall thickness of Class K9 ductile iron pipes is thicker than that of Class K7 and K8. In terms of quality, the nodulization grade of cast iron pipes is required to be controlled at Grade 1 to 3, so the mechanical properties of the material itself have been well improved, with the nature of iron and the performance of steel. This type of iron pipe has many advantages, such as excellent corrosion resistance, good sealing performance, and simple installation. It is mainly used for municipal administration, enterprise water supply, gas transmission, etc. During the casting process of ductile iron, it has a greater tendency to form white iron and higher internal stress compared with ordinary gray cast iron.

It is difficult for cast iron parts to obtain a pure ferrite or pearlite matrix. To improve the ductility or toughness of cast iron parts, they are often reheated to 900-950℃, held at this temperature for a sufficient time for high-temperature annealing, then furnace-cooled to 600℃ and taken out of the furnace to cool naturally. The annual production capacity of ductile iron pipes and flexible drainage pipes of our manufacturer is 300,000 tons. ### Cement Mortar Lining (Special Coating) This internal corrosion protection measure is suitable for pipelines transporting sewage, which can improve the corrosion resistance of the lining. ### Epoxy Coal Tar Pitch Coating Epoxy coal tar pitch coating is suitable for both gas pipelines and sewage pipelines. It is a two-component coating with high adhesion and a very smooth surface. ### Epoxy Ceramic Lining Epoxy ceramic lining is suitable for sewage pipelines and gas pipelines, but due to its difficult manufacturing process and high cost, it has certain limitations in application.

Epoxy ceramic lining has high adhesion and smoothness, making it an excellent corrosion-resistant coating. The annual sales volume of ductile iron pipes of our company is 120,000 tons, and that of flexible drainage pipes is 180,000 tons. The ductile iron pipes and flexible drainage pipes produced by our company are sold to Northeast China, North China, Central Plains, Northwest China and other regions. The tensile strength of ductile iron is 60K, while that of ordinary gray cast iron parts is only 31K. Another comparable aspect between the two is the yield strength: the yield strength of ductile iron parts is 40K, while that of ordinary gray cast iron parts is only 36K.