A 6 inch (nominal) ductile iron pipe has an outside diameter of 6.90 in (175.26 mm) per AWWA C151, combining high strength, corrosion protection, and versatile jointing to deliver 100 + years of reliable service across water, wastewater, irrigation, and industrial systems. Compliant with ANSI/AWWA C151, ISO 2531/EN 545, and other regional standards, these pipes minimize life-cycle costs and simplify installation via push-on or mechanical joints. A comparative OD table for 4″, 6″, 8″, 10″, and 12″ sizes is provided, plus FAQs and real-world case studies to guide specifiers and engineers.
🏭 Application Scenarios
-
Potable Water Distribution: Ideal for municipal mains and booster stations, ensuring safe, high-capacity flow in both trunk and lateral lines.
-
Wastewater & Sewage: Cement-mortar lining and external coatings resist aggressive effluents, making them suitable for gravity sewers and force mains.
-
Irrigation & Industrial Services: Handles high pressures and varied media—used in agricultural irrigation networks, chemical plants, and fire-protection mains.
🕰️ Service Life
Modern ductile iron pipes routinely achieve service lives exceeding 100 years, thanks to:
-
Recycled-content metallurgy and energy-efficient manufacturing.
-
Cement-mortar linings that eliminate internal corrosion when properly applied.
💪 Advantages
-
Superior Strength: Nodular-graphite structure delivers twice the tensile strength of gray iron, supporting classes up to 350 psi and beyond.
-
Robust Corrosion Protection: Internal cement-mortar lining plus external bonded zinc, asphalt, or polyethylene sleeving guard against soil and water attack.
-
Life-Cycle Cost Efficiency: Over a century, ductile iron pipe outperforms plastic alternatives in total ownership cost.
-
Joint Flexibility: Accommodates deflection and ground movement via push-on (Tyton) or restrained mechanical connections.
🌐 International Standards
-
ANSI/AWWA C151/A21.51 – Dimensional and pressure class requirements for 3″–64″ potable and reclaimed water mains.
-
ISO 2531 / EN 545 / EN 598 – Metric specifications for pipes, fittings, and joints in water and sewer applications.
-
Regional Norms: AS 2280 (Australia/New Zealand), GB/T 13295 (China), JWWA standards (Japan) ensure local compliance.
📊 OD Comparison Table
-
per AWWA C151 / BS EN 545 dimensions.
🚧 Installation & Jointing
-
Push-On (Tyton) Joints: Quick assembly, demountable, and allow angular deflection up to 5° per joint.
-
Mechanical Joints: Bolted glands provide positive restraint—ideal for high-pressure, seismic, or buried applications.
-
Flanged Ends: Standardized to BS EN 1092-2 PN16 for direct bolting to valves and pumps.
❓ FAQs
-
What pressure classes are available?
Ranges from 150 psi (Class K4) up to 350 psi (Class K12) per ANSI/AWWA C151. -
Is external encasement required?
Polyethylene sleeving per ANSI/AWWA C105 is recommended in corrosive soils. -
Recommended trench backfill?
Non-corrosive granular material; native soil if non-aggressive per C105 guidelines. -
Availability of fittings?
Tees, bends, reducers per ISO 2531/EN 545, offered in push-on, mechanical, or flanged ends.
📈 Case Studies
-
Municipal Main Upgrade: A U.S. city replaced 5 km of aging cast-iron with 6″ ductile iron (Class 350), saving $17 M NPV over 50 years according to Black & Veatch.
-
Highway Under-Crossing Leak Repair: A 6″ ductile iron water main beneath US 101 was successfully rehabilitated, preventing emergency-lane sinkholes and ensuring uninterrupted service.
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 | ….. |
