Ductile iron pipe Class K9 DN600 is primarily used in municipal water distribution for potable and raw water conveyance, as well as sewage and stormwater systems. Its robustness makes it ideal for industrial water networks, fire-fighting mains, and irrigation channels where reliability under pressure is critical.
In high-demand applications—such as skyscraper risers and hydroelectric conduits—the DN600 size provides the flow capacity needed for large-scale operations, while maintaining efficient hydraulic performance.
Service Life
Modern ductile iron pipe benefits from metallurgical improvements that deliver higher strength with reduced wall thickness, without sacrificing durability. Field studies indicate a design life of 100 years in benign soils, with well-maintained installations exceeding this benchmark.
Corrosion protection—via zinc coating, cement mortar lining, fusion-bonded epoxy, and optional polyethylene sleeving—extends service life even in aggressive environments, often achieving 50–80 years without major maintenance.
Installation & Connections
Push-On (Tyton) Joints
Flexible, gasketed push-on joints allow quick assembly without field welding, accommodating angular deflection up to 5° per joint for DN600–1600.
Restrained (K-Type) Joints
K-type restraining devices lock socket and spigot against axial movement, delivering zero-leak performance under high surge pressures and facilitating pre-laid testing before backfill.
Flanged Connections
Flanged ends—standardized to EN 1092-2—enable easy integration with valves, fittings, and pump equipment, with rated pressures up to PN 25.
Series Comparison & Price
Different K-classes correspond to varying wall thicknesses and pressure capacities. Below is a typical comparison for DN600:
| Class | Wall Thickness (mm) | Nominal Pressure (PN) | Approx. Weight (kg/m) | Price Range (USD/m) |
|---|---|---|---|---|
| K7 | 26 | PN 10 | 140 | 400 – 500 |
| K8 | 29 | PN 16 | 160 | 509 – 540 |
| K9 | 32 | PN 16–25 | 180 | 615 – 665 |
| K12 | 38 | PN 25–40 | 210 | 750 – 850 |
Class selection balances cost against pressure rating and mechanical robustness.
International Standards
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ISO 2531: Ductile iron pipes, fittings, accessories, joints for water applications.
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EN 545 / EN 598: European standards for drinking and wastewater pipes.
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ISO 4179 / ISO 8179: Internal cement mortar lining and external zinc coating requirements.
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ISO 21053: Life-cycle analysis and recycling evaluation for ductile iron pipes.
Compliance ensures global acceptance, ease of cross-border procurement, and interchangeability.
Advantages
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High Tensile Strength & Ductility withstands surge pressures and ground movement.
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Long Service Life over 100 years in benign soils, 50–80 years in aggressive conditions.
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Excellent Corrosion Resistance with proven zinc, epoxy, and mortar linings.
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Environmentally Friendly: recycled content, fully recyclable at end-of-life.
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Fast Installation: socketed, restrained, and flanged joints reduce downtime.
FAQ
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What defines Class K9?
A wall thickness of ~32 mm and pressure ratings PN 16–25, per ISO 2531. -
How long will DN600 K9 last?
Typically 100 years in non-corrosive soils; 50–80 years with standard protection in aggressive soils. -
What coatings and linings are available?
Portland cement mortar, sulfate-resistant lining (ISO 4179), internal epoxy, external zinc per ISO 8179, optional PE sleeving. -
Which joint type suits high-rise applications?
Restrained K-type joints for surge-free, leak-proof service under varying loads. -
How to specify for potable water?
Order per ISO 545, PN 16 flanged ends, cement-mortared interior, zinc exterior coating.
Case Studies
Berlin Water Supply Project, Germany
15 km of DN600 K9 pipe installed in 2016 using ordinary Portland cement lining. Achieved zero leakage and maintained hydraulic efficiency in urban distribution.
Eastern Terrace Watermain Upgrade, New Zealand
2455 m of DN600 mains improved supply reliability and reduced leakage by 30% for a suburban network.
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 | ….. |
