Class K8 DN1000 ductile iron pipe has a nominal wall thickness of 12.0 mm, calculated via ISO 2531’s formula e = K × (0.5 + 0.001 × DN) (K=8, DN=1000 mm) . Rated PN 12.5 (1.25 MPa), it serves medium-pressure water, sewage, irrigation, gas and fire mains . Cement-mortar lining (ANSI/AWWA C104) plus optional loose-fit polyethylene sleeving (ISO 8180) yield a design life exceeding 100 years, extending to 110 years in aggressive soils . Installation is rapid and leak-free via Tyton push-on, AWWA C111 mechanical and ANSI B16.1 flanged joints . In the K-series, nominal wall thickness climbs from 9.8 mm (K7) → 12.0 mm (K8) → 13.2 mm (K9) → 17.6 mm (K12), with K8 pricing typically US $885–895 / ton (20–99 ton MOQ) .
Applications
Ductile iron pipe is prized for:
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Potable Water Distribution: DN1000 mains deliver stable hydraulics and low leakage in large municipal networks .
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Sewage & Drainage: Abrasion-resistant core and smooth cement-mortar lining convey grit-laden wastewater reliably .
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Irrigation Systems: Uniform flow and surge resilience support large-scale agricultural supply lines .
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Gas Distribution: When produced per BS EN 969 and externally coated, DN1000 K8 pipes safely convey natural gas up to 16 bar .
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Fire-Protection Mains: High ductility and surge capacity ensure reliable hydrant loops and feeder mains .
Service Life
Modern ductile iron pipe outlasts most alternatives:
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Base Life: > 100 years in benign soils owing to its tough ferrous matrix .
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Cement-Mortar Lining (CML): Internal lining per ANSI/AWWA C104 guards against corrosion for > 100 years .
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Polyethylene Sleeving: Loose-fit sleeving per ISO 8180 adds ~10 years in aggressive soils, validated by Everglades test sites .
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Life-Cycle Savings: An AWWA study showed net savings of $47.68/ft over PVC (24″ Class 200 vs. PVC DR 18) and $17 million PV benefit over 50 years .
Installation & Connection
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Push-On (“Tyton”) Joints: Spigot-socket with elastomeric gasket for bolt-free, rapid sealing per ISO 2531 .
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Mechanical Joints: Gland-and-bolt restraint per AWWA C111 for both restrained and unrestrained connections .
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Flanged Joints: ANSI B16.1 (Class 125) flanges allow disassembly and resist high axial loads .
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Best Practices: 150 mm graded bedding, ≤ 3 % deflection, hydrostatic testing and chlorination per ISO 2531/AWWA C600 ensure joint integrity .
K-Series Comparison & Pricing
| Class | Nominal Wall Thickness<sup>1</sup> | Pressure Rating | Price (USD/ton)<sup>2</sup> |
|---|---|---|---|
| K7 | 9.8 mm = 7×(0.5+0.001×1000) | PN 10 (1.0 MPa) | $850–1,000 |
| K8 | 12.0 mm = 8×(0.5+0.001×1000) | PN 12.5 (1.25 MPa) | $885–895 (20–99 ton MOQ) |
| K9 | 13.2 mm = 9×(0.5+0.001×1000) | PN 16 (1.6 MPa) | $950–1,050 |
| K12 | 17.6 mm = 12×(0.5+0.001×1000) | PN 25 (2.5 MPa) | $1,100–1,300 |
<sup>1</sup>Per ISO 2531 & GB/T 13295 thickness formula.
<sup>2</sup>Based on quoted FOB prices from Chinese suppliers (Made-in-China, Alibaba).
International Standards
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ISO 2531:2009 / GB/T 13295-2019: Pipe dimensions, tolerances & joint performance.
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ISO 8180:2020: Polyethylene sleeving for corrosion protection.
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ANSI/AWWA C104/A21.4: Cement-mortar lining requirements .
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ANSI/AWWA C111/A21.11: Mechanical-joint specifications.
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ANSI B16.1: Flanged joint dimensions & ratings.
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BS EN 969:2009: Gas-pipeline DI pipes, fittings & accessories.
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ISO 1083:1997: Ductile iron grade JS I 350-22 mechanical properties (σb ≥ 350 MPa).
Advantages
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Outstanding Durability: 100+ year service life minimizes lifecycle replacements .
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High Strength & Toughness: Tensile ≥ 350 MPa resists surge and external loads .
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Comprehensive Corrosion Control: Internal CML, zinc/bitumen coatings & LPS .
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Jointing Versatility: Push-on, mechanical, flanged & restrained options suit any installation .
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Sustainability: Made from recycled iron, fully recyclable with low life-cycle energy use vs. plastics .
FAQ
Q1: How do K-series classes differ?
They follow e = K (0.5 + 0.001 DN)—for DN1000, K7=9.8 mm, K8=12 mm, K9=13.2 mm, K12=17.6 mm, correlating to PN 10/12.5/16/25 .
Q2: Which joint type is best?
– Tyton push-on: Fast, bolt-free assembly
– Mechanical: Restrained connections for valves/fittings
– Flanged: Easy disassembly & high axial-load capacity .
Q3: Is polyethylene sleeving necessary?
Recommended in aggressive soils—it adds ~10 years of protection, proven by Everglades tests .
Q4: What sizes & lengths are offered?
DN 80–2600 mm in 6 m laying lengths (5.7 m for container loads), with custom cuts on request .
Q5: Can DIP be used in seismic areas?
Yes—restrained joints (tie-rod, ball-and-socket) absorb ground movement for seismic resilience .
Case Studies
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AWWA LCCA (Huntsville, AL): 24″ Class 200 vs PVC DR 18 net savings of $47.68/ft and $17 million PV benefit over 50 years.
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Everglades City, FL: LPS-encased pipes remained in “excellent condition” after 10+ years in corrosive muck (140–240 Ω·cm) at DIPRA test sites .
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University of Michigan LCCA: Ductile iron mains showed lowest total lifecycle cost vs PVC, CI & steel in multiple climate zones.
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 | ….. |
