Class K7 ductile iron pipes are engineered to provide reliable and durable solutions for various water and wastewater infrastructure projects. Recognized for their strength, flexibility, and resistance to corrosion, these pipes are ideal for applications where moderate pressure handling is required.
Key Specifications
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Material: Ductile iron.
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Standard Compliance: ISO 2531, EN 545, AWWA C151/A21.51.
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Pressure Rating: Up to 7 bar (100 psi).
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Wall Thickness: Varies by diameter; typically ranges from 6.0 mm to 14.0 mm.
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Coatings: Cement mortar lining (ISO 4179), external coatings include zinc primer plus bitumen or epoxy painting.
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Joint Types: Push-on, ball-and-socket, and restrained joints.
Dimensional and Performance Comparison
| Nominal Diameter (DN) | Wall Thickness (K7) | Wall Thickness (K9) | Wall Thickness (K12) |
|---|---|---|---|
| 80 mm | 6.0 mm | 6.0 mm | 6.0 mm |
| 100 mm | 6.0 mm | 6.0 mm | 6.0 mm |
| 150 mm | 6.0 mm | 6.0 mm | 6.0 mm |
| 200 mm | 6.0 mm | 6.0 mm | 6.0 mm |
| 300 mm | 6.0 mm | 6.4 mm | 7.2 mm |
| 400 mm | 6.3 mm | 7.2 mm | 8.1 mm |
| 500 mm | 7.0 mm | 8.0 mm | 9.0 mm |
| 600 mm | 7.7 mm | 8.8 mm | 9.9 mm |
| 700 mm | 8.4 mm | 9.6 mm | 10.8 mm |
| 800 mm | 9.1 mm | 10.4 mm | 11.7 mm |
| 1000 mm | 10.5 mm | 12.0 mm | 13.5 mm |
| 1200 mm | 11.9 mm | 13.6 mm | 15.3 mm |
Note: Wall thicknesses are indicative and may vary based on manufacturer specifications.
Advantages
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Corrosion Resistance: Enhanced by cement mortar linings and external coatings, ensuring longevity in aggressive environments.
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Mechanical Strength: High tensile and yield strength provide resistance to internal pressures and external forces.
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Flexibility: Ability to withstand ground movements and thermal expansion due to ductile iron’s inherent flexibility.
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Ease of Installation: Variety of joint types facilitates straightforward assembly and reduces installation time.
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Longevity: Extended service life reduces the frequency and cost of replacements.
Applications
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Water Supply Systems: Transporting potable water in municipal and industrial settings.
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Sewerage Systems: Conveying wastewater with resistance to corrosion and structural integrity.
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Irrigation Networks: Delivering water for agricultural purposes under varying pressure conditions.
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Industrial Applications: Handling various fluids in chemical and manufacturing processes.
Comparison with K9 and K12 Classes
| Property | K7 Class | K9 Class | K12 Class |
|---|---|---|---|
| Pressure Rating | Up to 7 bar | Up to 10 bar | Up to 12 bar |
| Wall Thickness | Moderate | Thicker | Thickest |
| Weight | Lighter | Heavier | Heaviest |
| Cost | More economical | Higher | Highest |
| Suitable Applications | Moderate pressure | High pressure | Very high pressure |
Note: Pressure ratings are indicative and may vary based on specific standards and manufacturer specifications.
Market Price Comparison for Ductile Iron Pipes (per meter)
| Pipe Class | Price Range (USD/meter) | Notes |
|---|---|---|
| K7 | $400 – $500 | Suitable for low-pressure applications |
| K8 | $450 – $550 | Ideal for medium-pressure systems |
| K9 | $500 – $600 | Designed for high-pressure environments |
| K12 | $600 – $700 | Best for very high-pressure and critical infrastructure |
Prices are approximate and can vary based on diameter, wall thickness, coating type, and order quantity.
Class K7 ductile iron pipes offer a balanced solution for infrastructure projects requiring moderate pressure handling. Their compliance with international standards, combined with their mechanical properties and versatility, make them a preferred choice for engineers and project managers aiming for cost-effective and durable piping systems.
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 | ….. |
