A heavy-duty solution for large-diameter piping needs, the Class K9 DN2000 ductile iron pipe combines robust mechanical strength, long service life, and versatile joint options. Made to ISO 2531/EN 545 standards, it’s ideal for bulk water transmission, sewage mains, irrigation, and fire-fighting networks. K-series pipes (K7, K8, K9, K12) differ in wall-thickness and pressure ratings; a comparative table helps select the right class and budget. Engineered coatings and advanced laying methods ensure 100-year+ lifespans in most soils.
Application Scenarios
Ductile iron pipes excel in demanding fluid-transport systems. They are widely used for:
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Potable water transmission in municipal and bulk water mains.
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Sewer and wastewater conveyance in trunk and force mains.
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Industrial process lines (e.g., mining, petrochemical plants).
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Irrigation networks for agriculture and reclaimed water systems.
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Fire-fighting and hydrant systems, where high pressure and reliability are critical.
Service Life
Well-engineered ductile iron pipelines can exceed 100 years under “evolved laying practices” (including polyethylene sleeving).
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Cement-mortar internal lining prevents tuberculation and preserves flow capacity.
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External coatings (zinc, bitumen, epoxy) and loose polyethylene encasement guard against external corrosion.
Installation and Connection
Multiple joint types support various soil and pressure conditions:
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Push-on (T-type) joints with rubber gaskets for quick assembly.
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Mechanical joints for restrained connections under high thrust.
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Self-restrained (hidden-restrained) joints eliminating thrust blocks.
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Flanged ends for above-ground or special-access fittings.
Pipes are supplied in standard lengths of 5.5 m–6 m, customizable to 5.6–5.8 m as needed.
K-Series Comparison
| Class | Pressure Rating | Tensile Strength | Typical Price (USD/m) | Main Uses |
|---|---|---|---|---|
| K7 | 7 bar (700 kPa) | ≥ 420 MPa | 500–600 | Low-pressure water mains, rural supply |
| K8 | 8 bar (800 kPa) | ≈ 414 MPa | 510–570 | Medium-pressure distribution, sewer lines |
| K9 | 9 bar (900 kPa) | ≥ 420 MPa | 545–645 | High-pressure mains, fire-fighting networks |
| K12 | 12 bar (1200 kPa) | – | Contact supplier | Specialized high-pressure pipelines |
International Standards Compliance
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ISO 2531: Centrifugal casting, dimensional tolerances.
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EN 545 / EN 598: Requirements for water and sewage applications.
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AWWA C151 (USA): Ductile iron pipe for water transmission.
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ISO 1083 / EN 15655: Material grades and polyurethane lining specifications.
Advantages
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High strength & durability: Spheroidal graphite microstructure resists cracking and fatigue.
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Corrosion resistance: Modern linings/coatings extend service life in aggressive soils.
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Versatile installation: Supports a wide range of joint types and trench conditions.
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Recyclability: Iron content is 100% recyclable at end-of-life.
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Low life-cycle cost: Minimal maintenance over a century-long service.
Frequently Asked Questions
Q1: What’s the difference between K-class and C-class pipes?
K-class is based on pressure rating (bar), while C-class is based on minimum cement thickness (mm). For large diameters DN700–DN1200, C25/C30/C40 are common.
Q2: Can Class K9 handle sewage?
Yes—K9 pipes with cement-mortar lining meet EN 598 requirements for sewage and reclaimed water.
Q3: What trench bedding is recommended?
A well-graded granular bedding with compaction per EN 1610 and AWWA instructions ensures minimal deflection and long service.
Q4: How are thrusts managed at bends and tees?
Use mechanical or restrained joints, or thrust blocks, depending on joint type and soil conditions.
Case Studies
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Abu Dhabi Bulk Water Aqueduct: CLASSIC DN2000 pipes in desert transport 2 m³/s over 100 km with minimal maintenance.
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European Alpine Reservoir Feed: Saint-Gobain PAM DN1200–DN2000 range in mountainous terrain, enduring freeze–thaw cycles.
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Indian Sewage Trunk Main: DN1400–DN2000 pipes in corrosive soils, >50 years of reliable service to date.
ductile iron pipe dimensions
| Pipe body weight （kg/m) | |||||||||||||||
| (Inside Diameter) | (Outside Diameter) | Socket Weight | K8 | K9 | K10 | C class | Total weight of Active Length=6M (kg) | Total weight of Active Length=5.7M (kg) | |||||||
| DN(mm) | OD(mm) | ≈ kg | Class | kg/m | K8 | K9 | K10 | C class | K8 | K9 | K10 | C class | |||
| 80 | 98 | 3.40 | 12.20 | 12.20 | 12.20 | C40 | 9.10 | 77.00 | 77.00 | 77.00 | 58.00 | 73.00 | 73.00 | 73.00 | 55.00 |
| 100 | 118 | 4.30 | 14.90 | 15.10 | 15.10 | C40 | 11.12 | 93.70 | 95.00 | 95.00 | 71.00 | 90.00 | 91.00 | 90.00 | 68.00 |
| 125 | 144 | 5.70 | 18.90 | C40 | 119.00 | ||||||||||
| 150 | 170 | 7.10 | 21.80 | 22.80 | 22.80 | C40 | 16.48 | 138.00 | 144.00 | 144.00 | 106.00 | 132.00 | 138.00 | 137.00 | 101.00 |
| 200 | 222 | 10.30 | 28.70 | 30.60 | 30.60 | C40 | 22.62 | 183.00 | 194.00 | 194.00 | 146.00 | 174.00 | 185.00 | 185.00 | 139.00 |
| 250 | 274 | 14.20 | 35.60 | 40.20 | 44.30 | C40 | 32.63 | 228.00 | 255.00 | 280.00 | 210.00 | 218.00 | 244.00 | 267.00 | 200.00 |
| 300 | 326 | 18.90 | 45.30 | 50.80 | 56.30 | C30 | 43.90 | 290.00 | 323.00 | 357.00 | 282.00 | 278.00 | 309.00 | 340.00 | 269.00 |
| 350 | 378 | 23.70 | 55.90 | 63.20 | 69.60 | C30 | 51.88 | 359.00 | 403.00 | 441.00 | 335.00 | 343.00 | 384.00 | 420.00 | 319.00 |
| 400 | 429 | 29.50 | 67.30 | 75.50 | 83.70 | C30 | 60.78 | 433.00 | 482.00 | 532.00 | 394.00 | 414.00 | 460.00 | 506.00 | 376.00 |
| 450 | 480 | 38.30 | 80.00 | 89.30 | 99.00 | C30 | 73.30 | 515.00 | 575.00 | 632.00 | 472.00 | 492.00 | 550.00 | 597.00 | 450.00 |
| 500 | 532 | 42.80 | 92.80 | 104.30 | 115.60 | C30 | 87.20 | 600.00 | 669.00 | 736.00 | 566.00 | 572.00 | 638.00 | 702.00 | 540.00 |
| 600 | 635 | 59.30 | 122.00 | 137.30 | 152.00 | C30 | 120.62 | 791.00 | 882.00 | 971.00 | 783.00 | 755.00 | 842.00 | 926.00 | 747.00 |
| 700 | 738 | 79.10 | 155.00 | 173.90 | 193.00 | C25 | 142.15 | 1009.00 | 1123.00 | 1237.00 | 932.00 | 963.00 | 1071.00 | 1179.00 | 889.00 |
| 800 | 842 | 102.60 | 192.00 | 215.20 | 239.00 | C25 | 177.07 | 1255.00 | 1394.00 | 1537.00 | 1165.00 | 1197.00 | 1330.00 | 1465.00 | 1112.00 |
| 900 | 945 | 129.60 | 232.00 | 260.20 | 289.00 | C25 | 197.68 | 1521.00 | 1691.00 | 1863.00 | 1446.00 | 1452.00 | 1613.00 | 1777.00 | 1257.00 |
| 1000 | 1048 | 161.30 | 275.00 | 309.30 | 343.20 | C25 | 266.28 | 1811.00 | 2017.00 | 2221.00 | 1759.00 | 1729.00 | 1925.00 | 2118.00 | 1679.00 |
| 1100 | 1152 | 194.70 | 362.80 | 2372.00 | |||||||||||
| 1200 | 1255 | 237.70 | 374.00 | 420.10 | 466.10 | C25 | 373.88 | 2482.00 | 2758.00 | 3034.00 | 2481.00 | 2370.00 | 2632.00 | 2894.00 | 2369.00 |
| 1400 | 1462 | 279.30 | 547.20 | 3563.00 | |||||||||||
ductile iron pipe Mechanical property
| Mechanical Property | |||||||
| Nominal Diameter | Hydraulic test | Tensile strength | Elogation | Yield strength | Bending strength | Brinell hardness | Thickness of cement lining |
| DN(MM) | Mpa | Mpa | % | Mpa | Mpa | HB | mm |
| DN80-DN300 | 5 | ≥420 | ≥10 | ≥300 | ≥590 | ≤230 | 3 |
| DN350-DN600 | 4 | ≥420 | ≥10 | ≥300 | ≥590 | ≤230 | 5 |
| DN700-DN1000 | 3.2 | ≥420 | ≥10 | ≥300 | ≥590 | ≤230 | 6 |
| DN1100-DN1600 | 2.5 | ≥420 | ≥7 | ≥300 | ≥590 | ≤230 | ….. |
