The Class K7 DN400 Ductile Iron Pipe (nominal diameter 400mm) is a premium solution for demanding water, wastewater, and industrial pipeline systems. Built to exceed international standards, this pipe combines unmatched durability, ease of installation, and long-term cost efficiency. Below, we break down its features, applications, and advantages to help you make informed decisions for your projects.
Key Applications
Ideal for scenarios requiring high-pressure resilience and corrosion resistance:
- Municipal Water Networks: Safely distributes potable water under pressures up to 4.0 MPa (Class K7).
- Wastewater Systems: Resists hydrogen sulfide corrosion in sewage and stormwater pipelines.
- Industrial Use: Supports chemical plants, mining operations, and geothermal energy projects.
- Firefighting Infrastructure: Ensures reliable water supply for emergency systems.
- Irrigation: Reduces leakage by 30% compared to traditional PVC pipes (based on 2023 field tests in Spain).
100+ Year Lifespan – Built to Last
Ductile iron’s superior material properties, combined with advanced coatings, ensure decades of service:
- Corrosion Protection: Dual-layer linings (cement mortar + epoxy coating) reduce internal abrasion by 60% and external soil corrosion by 90%.
- Material Strength: Tensile strength of 420 MPa and elongation of 10% (exceeds ISO 2531 requirements).
- Case Study: A 2018 installation in Hamburg, Germany, reported zero leaks and <1% maintenance costs over 5 years.
Effortless Installation & Joint Reliability
Designed for quick deployment and secure connections:
- Flexible Joint Options:
- T-Joint: Allows 5° deflection per joint for uneven terrain.
- Flanged Connections: Ideal for above-ground industrial setups.
- Installation Speed: A 400m DN400 pipeline can be laid in 3 days (vs. 7 days for steel pipes).
- Leak Prevention: Rubber-sealed joints tested to withstand 10,000+ pressure cycles.
Certified Compliance & Global Standards
- ISO 2531 / EN 545: Guarantees dimensional accuracy and pressure performance.
- AWWA C151: Meets North American standards for ductile iron pipes.
- Third-Party Testing: Accredited by SGS, TÜV, and Lloyd’s Register.
Cost Comparison: Class K7 DN400 vs. Alternatives
| Material | Initial Cost (per meter) | Lifespan | Maintenance Cost (20 years) |
|---|---|---|---|
| Ductile Iron (K7) | $180 | 100+ years | $500 |
| PVC | $90 | 50 years | $1,200 |
| Steel | $250 | 70 years | $2,000 |
Note: Ductile iron offers 50% lower lifecycle costs than steel (World Piping Report, 2023).
Why Choose DN400 Class K7?
- Eco-Friendly: 100% recyclable; reduces CO2 emissions by 40% vs. new steel production.
- Adaptability: Works in temperatures from -30°C to 60°C.
- Customization: Available in 6m or 12m lengths, with optional anti-vibration coatings.
Frequently Asked Questions (FAQ)
Q: How does DN400 compare to DN350 in flow capacity?
A: DN400 delivers 25% higher flow rates (1,200 m³/h vs. 960 m³/h at 3 m/s velocity).
Q: Is trenchless installation possible?
A: Yes! Our pipes are compatible with microtunneling and pipe jacking methods.
Q: What warranty is provided?
A: A 20-year warranty against manufacturing defects, with optional extended coverage.
Real-World Success Stories
Project: Singapore’s Marina Bay Water Supply Upgrade
- Challenge: Replace aging asbestos cement pipes with a leak-resistant, high-capacity system.
- Solution: 8km of DN400 Class K7 pipes installed in 2022.
- Result: 15% improvement in water pressure and 90% reduction in pipe bursts year-on-year.
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 | ….. |
