Class K8 DN150 ductile iron pipe offers medium‑pressure capability (PN12.5) with a nominal wall thickness of 5.20 mm, combining exceptional strength, corrosion protection and 100 + year life expectancy. It is widely used in potable water, sewage, irrigation, gas and fire‑protection mains, and installs quickly via push‑on, mechanical or flanged joints. In the K series, K7→K8→K9→K12 increase in thickness and pressure rating (PN10→12.5→16→25), with prices ranging roughly from $480 to $900 USD/ton depending on class and finish.
Applications
Class K8 DN150 pipe is engineered for:
-
Potable Water Distribution: Reliable hydraulics and minimal leakage in urban networks.
-
Sewage & Drainage: Abrasion‑resistant conveyance of wastewater under medium pressures.
-
Irrigation Systems: Uniform flow in agricultural and horticultural applications.
-
Gas Distribution: When coated and tested per ISO 8180 for external protection.
-
Fire‑Protection Mains: High surge capacity and ductility for fire‑water networks.
Service Life
Modern ductile iron pipe is proven to exceed 100 years in benign soils; with cement‑mortar linings and advanced external coatings, life expectancy can reach 110 years under optimized conditions.Life‑cycle studies show present‑value savings in operating costs of over $17 million for a 50‑year service span using ductile iron versus alternatives.
Installation & Connection
-
Push‑On (“Tyton”) Joints: Simple, bolt‑free assembly with resilient gasket sealing.
-
Mechanical Joints: Gland‑and‑bolt restraint per ANSI/AWWA C111 for fittings and valves.
-
Flanged Joints: Removable connections per ANSI B16.1 or EN 1092 for maintenance access.
Product Series Comparison
| Class | Nominal Wall Thickness<sup>1</sup> | Pressure Rating | Typical Price<sup>2</sup> (USD/ton) |
|---|---|---|---|
| K7 | 7×(0.5 + 0.001×150) = 4.55 mm | PN10 (1.0 MPa) | $480 – 650 |
| K8 | 8×(0.5 + 0.001×150) = 5.20 mm | PN12.5 (1.25 MPa) | $500 – 700 |
| K9 | 9×(0.5 + 0.001×150) = 5.85 mm | PN16 (1.6 MPa) | $620 – 680 |
| K12 | 12×(0.5 + 0.001×150) = 7.80 mm | PN25 (2.5 MPa) | $700 – 900 |
1.Calculated per ISO 2531: e = K×(0.5 + 0.001 × DN).
2.Based on market surveys (Alibaba, Made‑in‑China) ŧ.
International Standards
-
GB/T 13295‑2019: Pipes, fittings & joints for water/gas (DN40–DN3000).
-
ISO 2531:2009 / EN 545:2006: Pipe dimensions, linings, joint performance.
-
ISO 8180:2020: Polyethylene sleeving for external corrosion control.
-
ANSI/AWWA C110/C111/C151: Flanged, mechanical joint & centrifugally cast pipe specs.
Advantages
-
Exceptional Longevity: 100 + year service life with minimal replacement.
-
High Strength & Toughness: Tensile ≥ 420 MPa resists surge pressures.
-
Comprehensive Corrosion Protection: Cement‑mortar lining, zinc/bitumen coatings, polyethylene sleeving.
-
Flexible Jointing Options: Push‑on, mechanical, flanged and restrained systems.
-
Sustainability: Recyclable iron with lower life‑cycle energy versus thermoplastics.
FAQ
Q1: How do K classes differ?
They vary by nominal wall thickness (e=K×(0.5+0.001×DN)) and corresponding pressure rating: K7→PN10, K8→PN12.5, K9→PN16, K12→PN25.
Q2: What lining & coating options exist?
Internal cement‑mortar, epoxy or ceramic; external bitumen, zinc + finish, polyethylene sleeving per ISO 8180.
Q3: Can DIP be used in corrosive soils?
Yes—use polyethylene encasement or cathodic protection to achieve 100 + year life even in aggressive environments.
Q4: What sizes & lengths are available?
DN 80–2600 mm, standard 6 m laying length (5.6–5.8 m effective) with custom cuts on demand.
Case Studies
-
Huntsville, AL (Black & Veatch): 50‑year PV savings > $17 million in energy & maintenance by choosing ductile iron over alternatives.
-
Florida Everglades Test Site (DIPRA): Loose polyethylene sleeving kept DIP in “excellent” condition after 10 years in aggressive soils.
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 | ….. |
