Class K12 DN80 ductile iron pipe is a high-performance, pressure-class piping solution designed for demanding potable water, wastewater, and industrial fluid transport applications. Featuring a nominal diameter of 80 mm and a K12 rating (12 bar), it meets ISO 2531, EN 545, and EN 598 standards, ensuring global compatibility and reliability. With a service life exceeding 100 years under normal operating conditions, Class K12 pipes offer exceptional longevity compared to alternative materials. Their versatile jointing options—push-on (T-type), mechanical (K-type), and self-restraining—simplify installation in trench and trenchless environments while minimizing leakage risks.
Application Scenarios
Class K12 DN80 pipes are widely employed in potable water networks, delivering clean drinking water from treatment plants to urban and rural consumers. They are also used for wastewater and sewage systems, where their smooth internal lining reduces fouling and hydraulic losses. In industrial plants, these pipes handle process water, cooling circuits, and fire-protection networks thanks to their high tensile strength and impact resistance. For subaqueous crossings and trenchless installations, ductile iron’s flexibility and robust external coating protect against soil movement and corrosion. Additionally, their seismic resilience makes Class K12 pipes preferred in earthquake-prone regions.
Service Life
Modern ductile iron pipes have an anticipated service life of 100 years or more, validated by dozens of utilities with mains active since the early 20th century. Monte Vista Water District reports a 100–125 year lifespan for ductile iron mains, offering unparalleled lifecycle value compared to PVC or HDPE alternatives. Long-term performance is supported by cement-mortar internal linings and fusion-bonded epoxy external coatings, which inhibit corrosion and maintain hydraulic capacity over decades.
Installation & Jointing
Class K12 DN80 pipes support multiple jointing systems:
-
Push-On (T-Type): Rubber-gasketed bells enable rapid assembly, reducing trench time and labor costs.
-
Mechanical (K-Type): Flanged couplings allow axial restraint and pressure rating up to PN25, ideal for high-pressure zones.
-
Self-Restrained: Integral anchoring patterns within the bell ensure thrust restraint without external blocks, streamlining thrust management in changes of flow direction.
Polyethylene encasement methods (Method A preferred) protect against stray current corrosion by wrapping each pipe joint and barrel with overlapped PE tubing.
International Standards
Class K12 DN80 pipes conform to:
-
ISO 2531:2015 – Ductile iron pipes, fittings, accessories, and their joints for water pipelines.
-
EN 545:2010 – Ductile iron pipes, fittings, and accessories for water supply.
-
EN 598:2007 – Ductile iron pipes, fittings, accessories, and valves for sewerage.
-
ASTM A 536 / C 151 – American standards for ductile iron pressure pipe.
-
GB 13295 – Chinese national standard for ductile cast iron pipes.
Price Comparison with Other Series
| Series / Class | China (USD/m) | India (USD/m) |
|---|---|---|
| Class K9 | 380 – 550 (approx. for DN80) | 16.7 (1300 INR) |
| Class K12 | 425 – 720 | 450 – 650 |
| PN10 (C25) | 350 – 500 | 400 – 550 |
| PN16 (C30) | 450 – 680 | 500 – 700 |
Note: Prices vary by coating, joint type, and order volume; consult local suppliers for precise quotations.
Key Advantages
-
Exceptional Durability: > 100 years lifespan reduces replacement cycles and full-life costs.
-
High Pressure Rating: K12 (12 bar) suits both municipal and industrial demands.
-
Corrosion Resistance: Cement-mortar lining plus fusion-bonded epoxy or bitumen exterior coatings extend service life.
-
Flexible Jointing: Multiple joint types adapt to diverse installation methods, including trenchless.
-
Seismic Performance: Superior strength and ductility sustain ground movement without catastrophic failure.
Frequently Asked Questions
Q1: What does “Class K12” mean?
A: “K”-classes denote pressure rating in bar; K12 supports up to 12 bar working pressure.
Q2: How is leak tightness ensured?
A: Push-on joints use EPDM rubber gaskets; mechanical and restrained joints incorporate gland plates and thrust blocks for robust sealing.
Q3: Can these pipes be installed under water?
A: Yes—subaqueous crossings benefit from ductile iron’s weight, coating protection, and self-restraining joints.
Q4: How do I choose between K9, K12, and C-class?
A: Base selection on design pressure, soil conditions, and replacement cycle goals; K12 suits higher pressures and longer lifespans.
Case Studies
-
San Lorenzo Valley, CA: After HDPE piping failed in the CZU fire, the water district noted ductile iron’s superior heat and mechanical resistance, preventing loss of 4.5 million gallons in similar scenarios.
-
Municipal Renewal Projects: Various U.S. and European cities have replaced aging gray-iron mains with K-class ductile iron, achieving reduced break rates and maintenance costs over 20 years.
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 | ….. |
