Class K12 DN1500 ductile iron pipe is a large-diameter (1500 mm ID) pipeline solution engineered for high-pressure water and sewage transmission, with a nominal wall thickness of approximately 24 mm calculated per ISO 2531 (e = K·(0.5 + 0.001 DN), K = 12). Centrifugally cast from GGG50 ductile iron, each length is internally lined with cement mortar (ISO 4179) and externally coated with zinc spray plus bituminous paint (ISO 8179) for superior corrosion protection. It complies with ISO 2531/EN 545 for potable water, EN 598 for sewerage, and ISO 13470 for trenchless jacking applications. Under normal soil and operating conditions, service life exceeds 100 years, as recognized by the DIPRA Century Club. Installation is rapid and leak-free via push-on (Tyton), mechanical restraint (AWWA C111), or ANSI B16.1 flanged joints, and supports open-trench, HDD, and pipe-jacking methods. Typical FOB China pricing ranges from USD 376 to 558 per meter depending on order quantity.
Application Scenarios
Municipal Water Transmission: As a primary trunk main in urban distribution networks, Class K12 DN1500 supports high flow rates with minimal head loss, meeting EN 545 purity and hydraulic performance requirements.
Sewage & Wastewater: Engineered for gravity and rising mains in collection systems, its smooth cement‐mortar lining minimizes deposition and hydraulic resistance.
Irrigation & Water Conservancy: Suited for long-distance conveyance in canals, reservoirs, and agricultural schemes, it maintains structural integrity across variable terrains.
Trenchless Construction: Compatible with HDD up to DN 1000 and pipe-jacking for DN > 1000, enabling installation beneath roads, railways, and waterways without open cutting.
Industrial & Building Services: Ideal for high-pressure loops in power plants, factories, and large-scale HVAC systems, offering resilience to vibration and surge loads.
Service Life
Modern ductile iron pipe consistently delivers over 100 years of reliable service, as documented by DIPRA’s Century Club utilities. Zinc/aluminum coatings provide sacrificial protection, while cement-mortar linings virtually eliminate internal corrosion, extending lifespan to 100–125 years with minimal maintenance . Independent tests confirm that properly specified and installed systems outperform alternative materials on total life-cycle cost and reliability.
Installation & Connection
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Joint Options: Push-on Tyton, K-type self-restraining, mechanical (AWWA C111), and flanged (ANSI B16.1) interfaces ensure rapid, tool-light assemblies with EPDM/SBR gaskets per ISO 4633.
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Axial Movement: Joints accommodate ±0.5 % deflection (~7.5 mm over a 6 m length) to absorb thermal expansion and ground settlement.
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Open-Trench & Trenchless: Standard open-cut installation follows AWWA C600 guidelines; HDD and pipe-jacking methods minimize surface disruption and speed up project schedules.
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Angular Deflection: Socket-spigot flexibility reduces the need for fittings, optimizing alignment and lowering installation costs.
International Standards
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ISO 2531 / EN 545: Ductile iron pipes, fittings, and accessories for potable water.
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ISO 7186 / EN 598: Products for sewerage applications.
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ISO 13470: Requirements for trenchless jacking pipe components.
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ISO 4179: Cement-mortar lining specifications.
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ISO 8179: Zinc coating and external protection standards.
Other Series Price Comparison
| Class | Nominal Wall Thickness (mm) | Price (USD/ton, FOB China) |
|---|---|---|
| K7 | 7·(0.5+0.001·1500)=14 | 700–900 |
| K8 | 8·(0.5+0.001·1500)=16 | 800–1 200 |
| K9 | 9·(0.5+0.001·1500)=18 | 470–570 |
| K12 | 12·(0.5+0.001·1500)=24 | 700–760 |
Advantages
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High Structural Strength: Resists internal pressures up to 3×PFA and external loads including traffic and ground settlement.
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Leak-Free Performance: Gasketed and restrained joints maintain integrity under surge and cyclic loading.
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Corrosion Resistance: Multi-layer protection (zinc/bitumen/PE sleeving) ensures durability in diverse soil chemistries.
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Sustainability: High recycled content, fully recyclable at end-of-life, and low overall carbon footprint.
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Flexible Alignment: Joint deflection reduces fittings, simplifies routing, and lowers installation time.
Frequently Asked Questions
Q1: What does Class K12 signify?
Wall-thickness class defined by ISO 2531: e = 12·(0.5 + 0.001 DN), yielding 24 mm at DN 1500.
Q2: Which standards govern DN1500 pipes?
Key standards include ISO 2531/EN 545 (water), ISO 7186/EN 598 (sewage), ISO 13470 (trenchless), ISO 4179 (lining), and ISO 8179 (coating).
Q3: How long will these pipes last?
With proper lining and coating, expected service life exceeds 100 years, often reaching 125 years with minimal intervention.
Q4: What installation methods are supported?
Compatible with open-cut, HDD, and pipe-jacking; joints include push-on, mechanical, and flanged types for fast assembly.
Q5: How does K12 compare cost-wise?
FOB China rates typically range USD 376–558/m; when life-cycle costs are considered, K12 often proves most economical over 100+ years.
Case Studies
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Landslide Mitigation, Santa Clara Valley (USA): S-type DN1500 pipes installed in parallel toeslide countermeasure, accommodating 9.4 ft total displacement over 50 years without loss of integrity.
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Mega Reservoir Project, Qatar: Kubota supplied earthquake-resistant jacking pipes for one of the Middle East’s largest water storage schemes, demonstrating ductile iron’s resilience and long-term performance.
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 | ….. |
