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Ductile Iron Pipe

Produced by centrifugal casting process using high-strength ductile cast iron, where graphite is spheroidized to enhance mechanical properties.

Classification :

Ductile Iron Pipe

WhatsApp : +8615666953306

E-mail : hdtsteel@aliyun.com

Product Description

Produced by centrifugal casting process using high-strength ductile cast iron, where graphite is spheroidized to enhance mechanical properties. Features excellent tensile strength, high impact resistance, good corrosion resistance, and superior ductility compared to gray cast iron. Available classes: K7, K8, K9, K10, K12, C25, C30, C40, C64 (ISO 2531), or Pressure Classes C20–C50 (EN 545). Diameter range: DN80 – DN2600mm (3″–102″). Wall thickness according to class and diameter. Length: standard 5.5m or 6m (custom available). Joint types: push-on (Tyton), restrained (standard or self-restrained), flanged, or mechanical joint. Internal lining: cement mortar (standard) or epoxy. External coating: zinc (minimum 130g/m²) + bituminous or epoxy finishing. Also available with polyurethane (PU) or fusion bonded epoxy (FBE) for aggressive environments. Meets ISO 2531, EN 545, EN 598, AWWA C151, or GB/T 13295 standards. Each pipe is hydrostatically tested and coated for corrosion protection.

Parameter

Product Name	Ductile Iron Pipe (Ductile Cast Iron Pipe)
Material	High-strength ductile cast iron (spheroidal graphite)
Manufacturing Process	Centrifugal casting (water-cooled or metal mold)
Diameter Range (DN)	DN80 – DN2600mm (3″ – 102″)
Standard Length	5.5m or 6m (other lengths available on request)
Pressure / Strength Classes	K7, K8, K9, K10, K12 (ISO 2531); C25, C30, C40, C64 (EN 545); Pressure Class C20–C50
Wall Thickness	According to class and diameter (e.g., DN100 K9: 4.4mm; DN200 K9: 5.0mm; DN500 K9: 7.0mm)
Tensile Strength	≥ 420 MPa
Yield Strength (0.5% offset)	≥ 300 MPa
Elongation	≥ 10% (typical 12–18%)
Hardness	≤ 230 HB (Brinell)
Internal Lining	Cement mortar (standard, thickness ≥ 3mm), epoxy (optional), polyurethane (PU)
External Coating	Zinc (≥ 130g/m²) + bituminous or epoxy topcoat; optional: polyurethane, FBE
Joint Types	Push-on (Tyton), restrained (standard / self-restrained), flanged, mechanical joint (MJ)
Gaskets	EPDM (standard), NBR, or SBR for water, sewage, or gas
Hydrostatic Test Pressure	100% tested: 4.5 MPa for DN ≤ 300; 3.5 MPa for DN 350–600; 2.5 MPa for DN ≥ 700 (ISO 2531)
Corrosion Protection	Internal cement lining; external zinc + bitumen; additional options for aggressive soils or wastewater
Application Media	Potable water, raw water, sewage, slurry, fire protection, irrigation
Standards Compliance	ISO 2531, EN 545 (water), EN 598 (sewage), AWWA C151, GB/T 13295

Application description:

Widely used for potable water transmission and distribution, sewerage systems (gravity and pressure mains), industrial wastewater lines, fire protection networks, irrigation projects, and pumping stations. Also suitable for raw water intake, desalination plants, and mining slurry transport. The high strength and corrosion resistance make it ideal for underground, high-pressure, and aggressive soil environments.

Production description

Molten iron is treated with magnesium to transform flake graphite into spheroidal form, enhancing strength and ductility. The treated molten metal is poured into a high-speed rotating water-cooled metal mold (centrifugal casting). Centrifugal force distributes the melt evenly, forming a dense pipe wall without a core. After solidification, the pipe is heat treated (annealing) to remove residual stresses. It is then hydrostatically tested, lined internally with cement mortar, and coated externally with zinc and bitumen or epoxy. Joints and gaskets are fitted before final inspection.

Shipping Packaging

For export, ductile iron pipes are bundled with wooden or plastic end caps, wrapped in moisture-proof polyethylene or shrink wrap, secured with steel straps, and packed in wooden crates, steel frames, or directly loaded into containers with blocking and bracing. Rubber gaskets are separately packed. Labels include class, DN, length, quantity, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength:Direct manufacturer with modern centrifugal casting lines, heat treatment furnaces, and in-house cement lining and coating facilities, ensuring consistent wall thickness, high strength, and full production control from molten iron to finished pipe.

2.Quality Assurance:Strict control of spheroidization grade (≥80%), mechanical properties (tensile ≥420MPa, elongation ≥10%), and pressure testing (100% hydrostatic); compliant with ISO 2531, EN 545/598, AWWA C151, GB/T 13295.

3.Certifications & Reports:Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV, Lloyd’s) and coating thickness/porosity reports available upon request.

4.Customization & Service:Wide range of diameters (DN80–DN2600), pressure classes (K7–K12, C20–C50), joint types (push-on, restrained, flanged, mechanical), internal linings (cement mortar, epoxy, PU), and external coatings (zinc+bitumen, FBE, PU) with fast lead times.

5.Export Packaging:Plastic end caps + moisture-proof wrapping + wooden crates/steel frames + steel strapping + separate packing for gaskets + blocking/bracing for container or flat rack loading, ensuring safe sea freight and damage-free delivery.

FAQ

1. What is the difference between ductile iron pipe and gray cast iron pipe?

Ductile iron pipe has spheroidal graphite structure after magnesium treatment, giving it much higher tensile strength (≥420MPa vs ≤250MPa) and elongation (≥10% vs 0%). It is impact-resistant and can withstand higher pressure without brittle fracture, while gray cast iron is brittle and not suitable for pressure pipelines.

2. How long is the service life of ductile iron pipes in underground applications?

With standard cement mortar lining and zinc+bitumen external coating, service life exceeds 50 years in normal soil conditions. For aggressive environments (acidic soil, high chlorides), optional polyurethane (PU) or FBE coatings can extend life to 80-100 years.

3. Can ductile iron pipes be used for sewage and wastewater?

Yes, EN 598 specifies ductile iron pipes for sewage applications. For sewage, we recommend internal lining of epoxy or PU (instead of cement mortar) to resist hydrogen sulfide corrosion, and external coating of polyurethane or high-build epoxy for aggressive buried conditions.