Ductile iron pipes are cast using methods similar to those of other industrial castings, but what sets Shanxi Jinsun Tong's ductile iron pipes apart is that prior to production, certain spheroidizing agents need to be added. These include magnesium or rare earth magnesium alloy spheroidizing agents, which are introduced into the molten iron before casting to spheroidize the graphite, reduce stress concentration, and give the pipes high strength, high elongation, good impact resistance, corrosion resistance, and excellent sealing properties. The inner walls are lined with cement mortar, which improves the water conveyance environment, enhances water supply capacity, and reduces energy consumption. The pipe ends feature flexible V-shaped joints, and the pipes themselves have a high external elongation rate (>10%), allowing for good flexibility in the pipeline. This enables them to work together with the surrounding soil in buried pipelines, improving the pipeline's stress state and thus enhancing the reliability of the pipeline network. Therefore, Shanxi Jinsun Tong's ductile iron pipes are commonly used as main materials in China's water supply industry. Our company currently has a large inventory of ductile iron pipes and offers them at preferential prices with both bulk and retail sales. We welcome new and existing customers to discuss and negotiate terms. Our pipe fitting products range from DN80 to DN2600 and can also be produced according to customer-specified standards. The annual output of pipe fittings exceeds two million tons, having been sold to provinces across China as well as to countries and regions in Europe, the Middle East, Southeast Asia, and others. Since its establishment, our company has always adhered to the "quality" principle. Our workshops, including the mold, machining, hydrostatic testing, laboratory, and sand cleaning workshops, are equipped with complete processing and testing facilities and were certified with the ISO9001:2000 quality management system in 2002.
Elbow fittings for ductile iron pipes are available in several types.
Socket weld pipe elbows are available in T, K, N1, and S types.
Ductile iron pipes are essentially spheroidal graphite cast iron pipes, as spheroidal graphite cast iron pipes possess the essence of iron and the properties of steel, hence the name. The graphite in spheroidal graphite cast iron pipes exists in a spherical form, with the size of the graphite typically ranging from 6 to 7 grades. In terms of quality, the spheroidizing grade of the cast iron pipes should be controlled at 1-3 grades, with a spheroidizing rate of ≥80%. This results in a significant improvement in the material's mechanical properties, offering the essence of iron and the properties of steel.
Features: Possesses the essence of iron, the properties of steel, excellent corrosion resistance, good ductility, easy installation, mainly used in municipal and industrial enterprises for water supply, gas transmission, etc.
Elbows come in three types from the joint perspective: double flanged, double socket, and socket-weld.
Each type of elbow fitting is available in four angles: 90, 45, 22.5, and 11.25 degrees.
So, there are a total of 3 x 4 = 12 elbow types.
Fourth, an indoor space that allows for continuous improvement should be considered. When using any piping component, most people are concerned about its durability and ease of repeated use without damage. An important factor is its recyclability for reuse and the prevention of new environmental pollution. For plastic hoses, most can recycle the waste materials for reuse. However, for PE-X and its waste or old pipes, they cannot be reused and are not dissolvable, which has always been a challenging issue to explore.
Ductile iron pipe production is a meticulous process. The ductile iron pipes used for high-pressure fluid conveyance, also known as daily welding pipes or commonly referred to as black pipes, are employed for conveying gas, oil, heating steam, and other high-pressure fluids, as well as for various other uses. The characteristics of these ductile iron materials are their smooth inner walls, light weight, corrosion resistance, good anti-scaling performance, and low cost. However, there are several drawbacks to note:
Old age, significant thermal expansion and contraction, unsuitable for prolonged exposure to sunlight, poor compressive properties, and the potential for poor dimensional stability during improper construction, are characteristics of cast iron pipes. These issues are mitigated by adding magnesium, calcium, and other alkaline earth metals or rare metals to the raw materials, which are then forged to create the pipes.
Ductile iron pipes are forged using continuous casting and water-cooled centrifugal forging methods, with the latter being a modern technique. Compared to simple cast iron pipes, the water-cooled method not only maintains corrosion resistance but also offers high strength, excellent toughness, thin walls, light weight, high impact resistance, large bending capabilities, and ease of installation. It has also been successfully implemented domestically. In many regions of China, ductile iron pipes are used for medium and small diameter pipe connections, employing socket-and-spigot or flanged joints; ductile iron allows for limited angles while maintaining superior seismic resistance and sealing properties.
Ductile iron pipes can be classified based on the wall thickness grade coefficient K or the allowable working pressure C. When classified based on the allowable working pressure C, large sizes up to DN1000, gas pipes should be classified based on the wall thickness grade coefficient K. The specific wall thickness and allowable pressure for self-anchoring joints are provided by the manufacturer.
Flexible interface components are denoted by a letter 'C' added before 10 times the PFA (Permitted Working Pressure) when classified by the allowed working pressure. For instance, if the PFA is 4Mpa, the pressure grade is 0.
How to improve the performance of ductile iron pipes? Currently, general gray cast iron or ductile iron castings often exhibit white mouth on the surface or thin-walled sections due to rapid cooling during the casting process, making the cast iron parts unsuitable for machining.
To eliminate the decrease in hardness due to white mouth, such cast iron parts are often heated from the beginning to above the eutectoid temperature, and then kept at temperature for 1 to 2 hours to anneal. The cementite decomposes into graphite, and the cast iron parts are then cooled slowly and removed from the furnace for air cooling.
Ballistic Malleable Cast Iron Annealing: During the casting process, grey cast iron pipes tend to have a white mouth and higher internal stress, making it difficult to achieve a pure ferrite or pearlite matrix in cast iron components. To enhance the ductility or toughness of cast iron, the components are typically heated to 900-950°C and held at this temperature for an adequate duration to undergo high-temperature annealing, followed by air cooling to 600°C. If the as-cast structure consists of a matrix and spherical graphite, to improve toughness, it is sufficient to decompose the cementite in the pearlite into ferrite and spherical graphite. For this purpose, the ductile cast iron pipe components are reheated to around 700-760°C, held at this eutectoid temperature, and then air cooled to 600°C for cooling out of the furnace. To improve the overall properties of cast iron components, the annealing of the ductile cast iron pipes, normalizing, quenching, and other methods to enhance the strength of malleable cast iron.
Shanxi Jinsuntong Company has an annual production capacity of 300,000 tons for ductile iron pipes and flexible drainage pipes; among which, the annual sales volume of ductile iron pipes is 120,000 tons and that of flexible drainage pipes is 180,000 tons. Our company's ductile iron pipes and flexible drainage pipes are sold to regions such as the Northeast, North China, Central Plains, and Northwest. The specifications for ductile iron pipes are from DN80mm to DN1200mm, and the national standard followed is GB/T 13295-2008. The specifications for cast iron drainage pipes range from DN50mm to DN300mm, with the standard being GB/T12772-2008. Shanxi Jinsuntong Ductile Iron Pipe Co., Ltd. has won customers with its strong technical strength, skilled workforce, and comprehensive testing equipment. The company adheres to the business philosophy of "Integrity, Cooperation, Innovation, and Win-Win," providing excellent service to customers. We are eager to cooperate sincerely with friends from all over the world to advance together, achieve mutual benefits, and create a better future. Here, the general manager and all staff of the company will serve the vast number of users with good reputation, strong capabilities, high-quality products, and low prices. We sincerely thank our old and new friends and customers for their constant care, support, and assistance. We sincerely hope to establish long-term cooperative relationships with them for mutual benefits and common development.
