Class K9 DN100 pipe features a nominal wall thickness of 5.22 mm—calculated via the ISO 2531 formula e = K × (0.5 + 0.001 × DN) for K=9, DN=100—delivering PN 16 (1.6 MPa) working pressure and a design life of 100+ years when cement-mortar lined and optionally polyethylene-sleeved . It installs fast via ISO 2531-compliant push-on (“Tyton”), AWWA C111 mechanical and ANSI B16.1 flanged joints . In the K-series (K7→K8→K9→K12), wall thickness increases (4.06 mm→4.64 mm→5.22 mm→6.96 mm) while PN rating rises (10 → 12.5 → 16 → 25 MPa), with K9 priced around US $425–485 per ton on global B2B platforms . Conforming to ISO 2531, EN 545/598, GB/T 13295 and AWWA standards, and validated by life-cycle studies showing a $47.68/ft cost advantage over PVC and “excellent” field performance, DN100 K9 is the durable, cost-effective choice for potable water, sewage, irrigation, gas and fire mains.
Applications
Potable Water Distribution
DN 100 K9 ensures leak-tight service in municipal networks, offering reliable hydraulics under variable demand.
Sewage & Drainage
Its abrasion-resistant core and cement-mortar lining convey grit-laden wastewater in gravity or force mains.
Irrigation Systems
Uniform flow and high surge capacity support agricultural and landscape irrigation.
Gas Distribution
When coated and tested per BS EN 969, K9 pipes safely transport gas at 16 bar, with certified joint integrity .
Fire-Protection Mains
High ductility and surge resilience make DN 100 K9 ideal for hydrant feeder and sprinkler mains .
Service Life
Modern ductile iron pipes exceed 100 years in benign soils due to their nodular-graphite matrix .
Cement-mortar lining (ANSI/AWWA C104) provides internal corrosion protection for over a century .
Loose polyethylene sleeving per ISO 8180 adds ~10 years in aggressive soils, with DIPRA tests showing “excellent” pipe condition after 10 + years .
AWWA life-cycle analysis reports a net $47.68/ft savings over PVC mains and a $17 million present-value benefit over 50 years .
Installation & Connection
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Push-On (“Tyton”) Joints: Spigot-socket with elastomeric gasket per ISO 2531 for bolt-free, rapid sealing .
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Mechanical (AWWA C111) Joints: Gland-and-bolt restraint offering both unrestrained and restrained assemblies .
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Flanged (ANSI B16.1) Joints: ANSI Class 125 flanges enable disassembly and high axial-load resistance .
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Best Practices: Use 150 mm well-graded bedding, limit deflection to ≤ 3 % of DN, and conduct hydrostatic testing & chlorination per ISO 2531/AWWA C600 .
K-Series Comparison & Pricing
| Class | Wall Thickness (mm) | PN Rating | Price (USD/ton) |
|---|---|---|---|
| K7 | 4.06 = 7×(0.5 + 0.001×80) | PN 10 (1.0 MPa) | $400 – 450 |
| K8 | 4.64 = 8×(0.5 + 0.001×80) | PN 12.5 (1.25 MPa) | $410 – 470 |
| K9 | 5.22 = 9×(0.5 + 0.001×80) | PN 16 (1.6 MPa) | $425 – 485 |
| K12 | 6.96 = 12×(0.5 + 0.001×80) | PN 25 (2.5 MPa) | $550 – 650 |
<sup>1</sup>Per ISO 2531 thickness formula.
<sup>2</sup>Alibaba pricing (DN 80–DN 2000 series).
International Standards
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ISO 2531:2009 / EN 545:2006 / EN 598:2007 – Pipe dimensions, linings & joint performance.
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GB/T 13295-2019 – Chinese standard for DIP, fittings & joints in water/gas systems.
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ANSI/AWWA C104/A21.4 – Cement-mortar lining specs.
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ANSI/AWWA C111/A21.11 – Mechanical-joint specs (DN 80–600 mm) .
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ANSI B16.1 / ASME B16.1 – Flanged joint dimensions & ratings.
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ISO 8180:2020 – Polyethylene sleeving for external corrosion control.
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BS EN 969:2009 – Gas-pipeline ductile iron pipe & accessories (≤ 16 bar).
Advantages
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Century-Scale Durability: > 100 year service life reduces replacements.
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High Strength & Toughness: Tensile ≥ 420 MPa resists surges & external loads.
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Multi-Barrier Corrosion Protection: CML, bitumen/zinc coatings & LPS.
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Jointing Flexibility: Push-on, mechanical, flanged & restrained options .
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Sustainability: High recycled content, fully recyclable, low life-cycle energy vs. plastics.
FAQ
Q1: How do K-series classes differ?
They follow e = K (0.5 + 0.001×DN)—for DN 100, K7=4.06 mm, K8=4.64 mm, K9=5.22 mm, K12=6.96 mm, corresponding to PN 10/12.5/16/25 MPa .
Q2: Which joint type is best?
– Tyton Push-On: Fast, bolt-free.
– Mechanical (AWWA C111): Restrained/unrestrained.
– Flanged (ANSI B16.1): Maintenance access & axial loads .
Q3: Is polyethylene sleeving necessary?
Recommended in aggressive soils for ~10 year life extension; validated by DIPRA .
Q4: What sizes & laying lengths are offered?
DN 80–2600 mm, standard 6 m (5.7 m for containers), custom cuts on request.
Q5: Can DIP be used in seismic zones?
Yes—restrained joints (tie-rod, ball-and-socket) absorb ground movement, ensuring integrity .
Case Studies
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DIPRA Everglades Test Site: LPS-encased pipes remained in “excellent condition” after 10+ years in corrosive muck (140–240 Ω·cm) .
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AWWA LCCA (Huntsville, AL): 24″ Class 200 DIP vs. PVC DR 18 delivered net $47.68/ft savings and $17 million PV advantage over 50 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 | ….. |
