January 21, 2025
Ductile iron pipe is made by melting scrap metal, then using a centrifugal casting machine to form the molten metal into a pipe. The pipe is then tested, inspected, and coated to prevent corrosion.
Ductile iron pipes (DIP) have become a cornerstone in modern infrastructure, known for their strength, durability, and reliability in water and wastewater systems. As one of the leading manufacturers of ductile iron pipes in China, Midas ensures that every pipe meets the highest standards, including EN598, EN545, and ISO2531. But how exactly are these robust pipes manufactured? In this article, we delve into the step-by-step process of making ductile iron pipes, highlighting the advanced techniques and quality controls that make them the preferred choice for demanding applications.
The process begins with the selection of high-quality raw materials. The primary component is pig iron, which is blended with recycled scrap iron and other alloys, such as magnesium, to enhance ductility. This composition is carefully controlled to ensure the final product achieves the required mechanical properties, including tensile strength, elongation, and impact resistance.
The raw materials are melted in an induction furnace at temperatures exceeding 1,500°C (2,732°F), creating a homogenous molten iron ready for further processing.
One of the key differentiators of ductile iron from traditional cast iron is its superior ductility. This is achieved through the addition of magnesium during the molten metal treatment. Magnesium reacts with the carbon in the iron, transforming the graphite flakes into spheroidal (nodular) shapes.
This transformation significantly improves the material’s tensile strength and flexibility, making it resistant to cracking under pressure. The treated molten iron is then ready for casting.
Ductile iron pipes are manufactured using the centrifugal casting method, a process that ensures uniform wall thickness and a smooth internal surface. In this method:
Molten iron is poured into a rotating steel mold.
The centrifugal force distributes the molten iron evenly along the inner surface of the mold, forming the pipe’s shape.
As the mold continues to rotate, the iron cools and solidifies, creating a dense, void-free structure.
This process is highly efficient, enabling the production of pipes with diameters ranging from DN80 to DN2600, meeting a wide range of project requirements.
After casting, the pipes undergo an annealing process in a controlled atmosphere furnace. Annealing involves heating the pipes to a specific temperature and then gradually cooling them to relieve internal stresses and enhance mechanical properties.
This step is crucial for ensuring the pipes can withstand high pressures and maintain their structural integrity over decades of use.
To protect the pipes from corrosion and extend their service life, a protective coating is applied to both the interior and exterior surfaces. Common coatings include:
Exterior Coating: Zinc, bitumen, or epoxy resin coatings are applied to shield the pipes from environmental factors like moisture and soil acidity.
Interior Lining: Cement mortar, epoxy, or polyurethane linings are used to protect the pipes from corrosion caused by the transported fluid.
Midas also offers customizable coating options to meet specific project needs, ensuring the pipes perform reliably in various environmental conditions.
Every pipe undergoes rigorous quality control checks to ensure compliance with international standards such as ISO2531, EN545, and EN598. Key inspections include:
Dimensional Accuracy: Pipes are measured to confirm they meet the specified diameter and wall thickness.
Hydrostatic Testing: Each pipe is subjected to high-pressure water tests to ensure it is leak-proof.
Visual and Ultrasonic Testing: Surface and internal inspections are conducted to detect any defects or irregularities.
These stringent quality checks guarantee that Midas pipes are safe, reliable, and built to last.
Once inspected and approved, the pipes are cut to the required lengths and finished with beveled or plain ends. They are then carefully packaged to prevent damage during transportation.
Midas ensures all pipes are securely wrapped and labeled, ready for delivery to customers around the globe.
Environmental Sustainability
Ductile iron pipes are not only durable but also environmentally friendly. The manufacturing process incorporates up to 90% recycled materials, and the pipes themselves are 100% recyclable at the end of their service life.
Additionally, the smooth interior lining reduces friction, improving flow efficiency and reducing energy consumption in pumping systems.
At Midas, we combine advanced manufacturing techniques with stringent quality controls to deliver pipes that meet the highest industry standards. Our ductile iron pipes are acclaimed for their:
Wide Diameter Range: From DN80 to DN2600, suitable for any application.
High Performance: Superior strength, ductility, and corrosion resistance.
Customizability: Tailored coatings and linings to meet specific project requirements.
Reliability: Proven performance in municipal water systems, industrial pipelines, and more.
The manufacturing of ductile iron pipes is a sophisticated process that combines cutting-edge technology with meticulous attention to detail. From raw material selection to quality inspection, every step is designed to produce pipes that deliver unmatched performance and durability.
If you’re looking for high-quality ductile iron pipes at competitive prices, Midas is your trusted partner. Contact us today to learn more about our products and how we can support your next project!
