How to improve the performance of ductile iron pipes? Currently, gray iron or ductile iron castings often exhibit white mouth on their surfaces or thin-walled sections due to rapid cooling during the casting process, making them 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 slowly cooled and removed for air cooling.

.Grain-refined ductile iron annealing; During the casting process, the gray iron pipes tend to have a white mouth like general gray cast iron, and the internal stress is also high, making it difficult to achieve a pure ferrite or spheroidized pearlite matrix in cast iron parts. To improve the ductility or toughness of cast iron parts, they are often heated from the beginning to 900-950°C and held at temperature for a sufficient duration to undergo high-temperature annealing, followed by cooling in the furnace to 600°C. If the as-cast structure consists of the matrix and spheroidal graphite, to enhance toughness, it is sufficient to decompose the cementite in the spheroidite into ferrite and spheroidal graphite. For this purpose, the ductile iron pipe components are reheated to temperatures around 700-760°C, held at this temperature, and then cooled in the furnace to 600°C for further cooling. To improve the overall performance of cast iron parts, the annealing of grain-refined ductile iron pipes, normalizing, quenching, and other processes to enhance the strength of spheroidal iron.

Shanxi Jinsuntong Company has an annual production capacity of 300,000 tons for ductile iron pipes and flexible drainage pipes; among them, the annual sales volume of ductile iron pipes is 120,000 tons, and the annual sales volume of flexible drainage pipes is 180,000 tons. Our company's ductile iron pipes and flexible drainage pipes are sold to regions such as Northeast China, North China, Central Plains, and Northwest China. The specifications of the ductile iron pipes are DN80mm-DN1200mm, and the national standard followed is GB/T 13295-2008. The specifications of cast iron drainage pipes are DN50mm-DN300mm, and the standard is GB/T12772-2008. Shanxi Jinsuntong Ductile Iron Pipe Co., Ltd. has won customers with its strong technical strength, skilled workforce, and complete detection equipment. The company adheres to the business philosophy of "Integrity, Cooperation, Innovation, and Win-Win," providing excellent services to customers. We are willing to sincerely cooperate with friends from all over the world, move forward together, and achieve mutual benefits and win-win results, creating a better future together! Here, the general manager and all employees of the company will serve the vast number of users with good reputation, strong strength, superior products, and low prices. We sincerely thank our old and new friends and customers for their continuous care, support, and assistance. We sincerely hope to establish a long-term cooperative relationship with them, achieve mutual benefits, and seek common development.

To prevent damage to ductile iron pipes, asphalt paint or epoxy coatings can be applied, as well as aluminosilicate cement, salt cement, and polyurethane coatings, which can resist erosion from acidic and alkaline components in sewage. Ductile iron pipes are subject to various factors during use and can suffer varying degrees of damage. Additionally, cement mortar lining with special coatings can be used inside the ductile iron pipes to enhance their corrosion resistance and protect water quality (the cement sand lining of general ductile iron pipes should be inspected by the health quarantine department before use). Ductile Iron Pipe Product Standards

B/T Ductile Iron Pipes, Fittings, and Accessories for Water and Gas Pipelines; GB/T General Requirements for the Casing of Ductile Iron Pipes by Centrifugal Method Using Cement Mortar; GB/T Composition Test of Freshly Mixed Mortar for the Casing of Ductile Iron Pipes by Centrifugal Method; GB/T Ductile Iron Pipes with Asphalt Coating; GB/T 17456 Zinc Spray on the Outer Surface of Ductile Iron Pipes; GB/T Safety Evaluation Standard for Equipment and Protective Materials for Drinking Water Transmission and Distribution

1. Selection of ductile iron pipe materials should be based on the specific conditions of the installation site, choosing the interface form between straight pipes and fittings. 2. Rubber rings are commonly made of materials such as NBR, SBR, and EPDM. 3. Coating selection: Choose an appropriate coating based on the internal and external conditions during use. The new ductile iron pipes available include epoxy resin inner coating, polyurethane inner and outer coating, and PE film coating. When selecting, be sure to understand their properties in detail.

Ductile iron pipes with cracks can be repaired using a cast iron defect repair machine, but not all issues can be resolved with such equipment. If the pipe cracks are due to excessive temperature during heat treatment during casting, or the absence of appropriate additives to prevent overly hard changes and maintain adequate brittleness, the pipe will crack. If the performance of the pipe does not meet the required standards, especially if it is subjected to high pressure, it will need to be recast for a new one. The most common leakages occur at pipeline joints. There are many reasons, and the main factors are as follows:

1. The damage is at the joint of the pipe and fitting, or the fitting itself. Solution: Minor leakage can be焊接 treated, while severe leakage requires being fully covered with cement for protective treatment.

2. Ductile iron pipes are not properly seated or the installation angle exceeds the standard. Solution: Check the installation line printed at the socket, confirm if it is installed according to specifications.

3. The socket of the ductile iron pipe is elliptical, and the rubber ring does not provide a sealing effect. Solution: Replace with a qualified product or round it up.

4. The rubber ring in the ductile iron pipe is flipped over, causing damage and rendering it ineffective for sealing. Solution: Reinstall correctly.

5. The socket of the ductile iron pipe has debris adhered, not cleaned properly, and the gasket fails to provide a seal. Solution: Reinstall correctly.

6. The rubber ring has poor quality; it cannot recover its elasticity after being compressed and fails to provide a sealing function. Solution: Replace with a qualified product. If replacement is not possible, use a cast iron hub (for the socket) as a temporary solution.

7. Radial dimensions of pipes or O-rings are non-compliant, or they are not compatible with each other, resulting in poor sealing. Solution: Replace with qualified products.

Several types of elbows are available for ductile iron pipes.

Socket weld elbow of ductile iron pipe comes in T, K, N1, and S types.

Ductile iron pipes are essentially spheroidal cast iron pipes, as spheroidal cast iron pipes possess the inherent properties of iron and the performance of steel, hence the name. The graphite in spheroidal cast iron pipes exists in spherical form, generally ranging from 6 to 7 grades. The quality requirements specify that the spheroidizing grade of cast iron pipes be controlled at 1-3 grades, with a spheroidizing rate of ≥80%. This ensures that the material itself has been significantly improved in mechanical properties, retaining the essence of iron and the performance of steel.

Features: Iron in nature, steel in performance, excellent corrosion resistance, good ductility, easy installation, mainly used for municipal and industrial enterprises in water supply, gas transmission, etc.

Elbows come in three types from the joint perspective: flanged, socket weld, and socket union.

Each type of elbow fitting comes in four angles from the bend degree: 90, 45, 22.5, and 11.25.

So, there are a total of 3 x 4 = 12 elbow types.

Fourth, a continuous improvement in indoor space is crucial, especially when using various fittings. Most people are concerned about the durability of these fittings, not easily damaged. An important factor lies in their ability to be recycled and reused without causing new environmental pollution. For plastic hoses, most can recycle and reuse the scrap. However, for PE-X and its waste or old pipes, they cannot be reused and are not recyclable, which has become a challenging research issue.

Ductile iron pipe production requires meticulous attention. Ductile iron pipes used for high-pressure fluid transmission, also known as daily welding pipes or commonly referred to as black pipes, are employed for the transmission of gases, oils, heating steam, and other high-pressure fluids, as well as various other applications. The characteristics of ductile iron materials used in these pipes include smooth inner walls, light weight, excellent corrosion resistance, good anti-scaling performance, and low cost. However, there are also several drawbacks to consider:

Additives of magnesium, calcium, and other alkaline earth metals or rare metals are used to forge the raw materials of old iron pipes, which are prone to aging, have significant thermal expansion and contraction, are not suitable for prolonged exposure to sunlight, have poor compressive properties, and are prone to deformation and poor flexibility if not properly installed.

Ductile iron pipes are forged using either continuous casting or water-cooled centrifugal forging methods, with the latter being a modern technique. Compared to ordinary cast iron pipes, the water-cooled method not only improves corrosion resistance but also offers high strength, good ductility, thin walls, lightweight, high impact resistance, large bending capabilities, and easy installation. This method has also been successfully implemented in China. In many areas of China, ductile iron pipes are used for medium and small diameter supply and connection, employing socket or flange-type joint methods; ductile iron allows for limited bending angles while maintaining excellent seismic resistance and sealing properties.

Ductile iron pipes can be classified based on the wall thickness coefficient K or the allowable working pressure C. When classified by the allowable working pressure C, sizes range from DN1000 and above. For gas pipes, classification should be based on the wall thickness coefficient K. The specific wall thickness and allowable pressure for self-anchoring joint pipes are provided by the manufacturer.

Flexible interface components are denoted by adding the letter "C" in front of 10 times the PFA (Permitted Working Pressure) when categorized by working pressure. For example, if the PFA is 4Mpa, the pressure grade is 0.