The Class K7 DN1200 ductile iron pipe is engineered for heavy-duty fluid transportation in municipal water systems, industrial drainage, and seismic-resilient infrastructure. With a nominal diameter of 1,200 mm, it delivers exceptional pressure resistance (up to 3.2 MPa) and longevity exceeding 60+ years due to advanced dual-layer anti-corrosion coatings (zinc-aluminum + bitumen) and a wall thickness of 20.7 mm (calculated using the formula e = K × (0.5 + 0.001 × DN)). Designed for global interoperability, it meets ISO, EN, and ASTM standards, making it ideal for projects demanding reliability and sustainability.
Key Features & Advantages
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Superior Structural Integrity
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Tensile Strength: ≥420 MPa | Yield Strength: ≥300 MPa.
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Pressure Resistance: 25% higher than K9-grade pipes due to optimized wall thickness.
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Corrosion Protection: Dual-layer coating extends service life by 4x compared to conventional steel.
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Seismic & Thermal Adaptability
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Flexible T-type joints tolerate 50 mm axial deformation and 40 mm lateral vibration, ideal for earthquake-prone regions.
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Operational range: -40°C to 400°C, suitable for Arctic pipelines or high-temperature industrial discharge.
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Eco-Friendly Design
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100% recyclable with zero toxic emissions, aligning with global sustainability goals.
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Applications
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Municipal Water Supply: Safely delivers potable water to cities with populations exceeding 1 million.
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Industrial Waste Systems: Resists chemical abrasion in mining, power plants, and chemical processing facilities.
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Flood Control Infrastructure: High-capacity drainage for coastal and monsoon-prone regions.
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Seismic Zones: Prevents rupture during earthquakes up to 7.5 magnitude due to flexible joint systems.
Installation & Connection Methods
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T-Type Flexible Joints:
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EPDM rubber seals ensure leak-free assembly, compliant with ISO 2531 and CJ/T 156-2001 standards.
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Angular deflection tolerance: ±3° per joint for uneven terrains.
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Flanged Connections:
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ASTM A536-certified bolts ensure uniform pressure distribution (torque: 180–220 Nm).
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Step-by-Step Installation:
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Cut pipes using diamond-tipped blades for precision.
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Align sockets and insert lubricated rubber gaskets.
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Secure joints with corrosion-resistant clamps or bolts.
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International Standards Compliance
| Standard | Scope | Key Requirement |
|---|---|---|
| ISO 2531 | Global specifications for ductile iron pipes | Pressure rating ≥3.2 MPa for DN1200 |
| EN 545 | EU drinking water safety | Lead-free cement lining |
| GB/T 13295 | Chinese K7-K12 pressure grading | Wall thickness tolerance ≤±5% |
| ASTM A536 | Mechanical properties | Charpy impact ≥7 J at -20°C |
Price Comparison (USD/Ton)
| Grade | Pressure Rating | Typical Use Case | Price Range |
|---|---|---|---|
| K7 | 3.0–3.2 MPa | High-pressure water systems | 950 |
| K9 | 2.5–3.0 MPa | Urban drainage | 800 |
| C40 | 2.0–2.5 MPa | Low-pressure irrigation | 700 |
Bulk discounts available for orders ≥500 tons.
Case Studies
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Middle East Desalination Mega-Project:
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Challenge: Extreme salinity (TDS >40,000 ppm) and soil erosion.
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Solution: DN1200 K7 pipes with hybrid epoxy-zinc coating.
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Result: Zero corrosion damage over 15 years; maintenance costs reduced by 55%.
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Japanese Coastal Flood Management:
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Challenge: Frequent typhoons and soil liquefaction.
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Solution: K7 pipes with T-type joints and reinforced bedding.
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Result: Survived 8.0-magnitude earthquakes; system downtime reduced by 80%.
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Frequently Asked Questions
Q: Why choose K7 over K9 for DN1200 pipelines?
A: K7’s wall thickness coefficient (K=7) provides 22% greater structural integrity, enabling a 3.2 MPa pressure capacity vs. K9’s 2.5 MPa limit.
Q: Can these pipes withstand acidic coastal soils?
A: Yes. The zinc-aluminum coating forms a stable carbonate layer in acidic soils (pH 4–6), preventing electrochemical corrosion.
Q: Do you offer custom linings for DN1200 pipes?
A: Custom options include polyurethane, epoxy, and silicate cement linings for specialized environments.
Why Partner With Us?
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Certifications: ISO 9001, EN 545, and API 5L.
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Global Logistics: 15-day delivery to major ports; 24/7 multilingual technical support.
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Sustainability: Carbon-neutral manufacturing and ISO 14001 compliance.
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 | ….. |
