The Class K7 DN500 ductile iron pipe (500mm diameter) is built for durability and efficiency in medium-to-large water systems. With a 7-bar pressure rating, it handles demanding applications while maintaining leak-free performance.
Key Highlights:
- Strength & Longevity: Minimum tensile strength of 420 MPa and elongation ≥10% ensure resilience against stress and ground movement.
- 100+ Year Lifespan: Engineered to last over a century under normal conditions, reducing long-term replacement and maintenance costs.
- Easy Installation: Compatible with push-on (Tyton), mechanical, and flange joints for fast, secure connections in trenches or above-ground setups.
- Global Compliance: Meets ISO 2531, EN 545, EN 598, and ANSI/AWWA C151 standards for reliable performance worldwide.
- Cost Efficiency: Factory pricing ranges from $55–68 per meter (average weight: 135 kg/m), offering long-term savings over alternatives.
Application Scenarios
Class K7 DN500 excels in municipal water distribution, where large‑diameter mains require steady pressure control and minimal leakage; utilities worldwide rely on DI mains for critical supply lines. It’s also widely used in sewage and wastewater systems, benefiting from DI’s ability to handle aggressive media without structural degradation. In industrial plants—including power generation, chemical processing and manufacturing—its chemical resistance and mechanical strength ensure reliable performance in diverse process lines. For agricultural irrigation, DN500 mains deliver high‑volume flows over long distances, withstanding soil movement and climatic shifts without compromise.
Service Life
-
Century‑Plus Durability: Field records and DIPRA research confirm modern ductile iron pipes last over 100 years in potable and raw water service.
-
Low Maintenance: With internal cement mortar linings and external bitumen or zinc‑alloy coatings, DI mains resist corrosion and require minimal upkeep, as noted by ASCE performance analyses.
-
Recyclable Material: Produced with significant recycled iron content and fully recyclable at end‑of‑life, DN500 DI pipes support circular‑economy goals.
Installation & Connection
Joint Methods
-
Push‑On (Tyton) Joint: Simplest to install, providing a watertight seal via gasket compression—ideal for most underground applications.
-
Mechanical Joint: Comprises a bell, gland and bolts for higher restraint; suited where thrust blocks are impractical.
-
Flange Joint: Offers full‑face sealing for above‑ground installations or where frequent disassembly is required.
Trenching & Bedding
Pipes rest on well‑graded granular bedding; backfill is compacted in layers to prevent settlement. Polyethylene encasement (Methods A/B/C) can be applied in corrosive soils.
International Standards
-
ISO 2531 / EN 545 / EN 598: Define dimensions, tolerances, mechanical properties and linings for DN 80–DN 2600 pipes.
-
ANSI/AWWA C151/A21.51: Covers DI pipe 80–1600 mm for potable, raw and wastewater, specifying material, dimensions, coatings and joint types.
-
Quality Certifications: Many manufacturers hold ISO 9001, ISO 14001, NSF and WRAS approvals to guarantee production consistency and potability compliance.
Price Comparison with Other Series
| Class | Wall Thickness (K-type) | Approx. Price (USD/ton) | Approx. Price (USD/m)¹ |
|---|---|---|---|
| K7 | 6.0 mm | 400 – 500 | 54 – 68 |
| K8 | 6.8 mm | 450 – 550 | 61 – 74 |
| K9 | 9.0 mm | 500 – 600 | 68 – 81 |
¹ Based on 135 kg/m average weight for DN500 class.
Advantages
-
High Corrosion Resistance: Bitumen, epoxy or zinc‑aluminum coatings plus cement mortar lining protect against internal and external corrosion.
-
Excellent Impact Strength: Verified per ANSI/AWWA C151, DI pipe endures water hammer, traffic loads and handling shocks.
-
Structural Flexibility: Ductility allows pipes to flex under soil shifts and seismic activity without fracturing.
-
Sustainable & Recyclable: Made with recycled content; 100% recyclable at end‑of‑life.
FAQs
-
What does DN500 mean?
It indicates a Nominal Diameter of 500 mm; actual internal diameter varies by class and lining. -
What is Class K7?
A pressure class rated for 7 bar working pressure, with a minimum tensile strength of 420 MPa and ≥ 10% elongation. -
How long will the pipe last?
Over 100 years under typical potable‑water conditions, per DIPRA longevity data. -
What joint options are available?
Push‑on (Tyton), mechanical and flange joints; choose based on thrust, maintenance and installation needs. -
Is ductile iron pipe environmentally friendly?
Yes—high recycled content, low energy use in service, and fully recyclable at end‑of‑life.
Case Studies
-
Harcourt Rural Modernisation (Victoria, Australia): 19 km of DN500+ DI mains delivered by Pentair for Coliban Water’s USD 40 million upgrade, showcasing ease of installation and long‑term reliability.
-
Global Municipal Projects: DIPRA catalogues citywide deployments of large‑diameter DI mains, documenting reduced leak rates and predictable maintenance costs in varied climates.
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 | ….. |
