Class K8 DN200 ductile iron pipe features a nominal wall thickness of 6.0 mm, calculated per ISO 2531’s thickness formula e = K (0.5 + 0.001 DN) with DN 200 mm and K = 8. It is designed for medium pressures (approx. PN 12.5), serving potable water, sewage, irrigation, gas and fire‑protection mains. Cement‑mortar linings and polyethylene encasement extend life well beyond 100 years in benign soils—and up to 110 years with enhanced corrosion control. Installation uses push‑on (“Tyton”), mechanical or flanged joints per ISO 2531, EN 545 and AWWA standards. Among K‑series classes, wall thickness rises from 6.0 mm (K7/K8) to 6.3 mm (K9) to 8.4 mm (K12), with prices ranging roughly $480–900 USD/ton depending on class, quantity and finish. Case studies—such as Huntsville Utilities’ $17 million PV energy savings over 50 years and Everglades City’s “excellent” LPS performance—underscore DIP’s durability and cost‑effectiveness .
Applications
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Potable Water Distribution: Proven leak‑tight, large‑diameter mains for urban supply networks.
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Sewage & Drainage: Abrasion‑resistant conveyance of wastewater in gravity or force mains.
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Irrigation Systems: Stable hydraulic performance under variable flows in agriculture.
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Gas Distribution: When produced and tested per EN 969, delivers safe, leak‑tight gas service.
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Fire‑Protection Mains: High surge resilience and ductility ensure reliable fire‑water delivery.
Service Life
Unprotected ductile iron pipe can exceed 100 years in non‑corrosive soils; with loose polyethylene sleeving, life expectancy reaches 110 years under optimized laying practices. At Florida’s Everglades test site, LPS‑encased pipes remained in “excellent condition” after over 10 years in aggressive muck. In Huntsville, AL, a Journal AWWA study found annual pumping‑cost savings of $666,999, yielding a $17 million present‑value benefit over 50 years versus PVC mains.
Installation & Connection
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Push‑On (“Tyton”) Joints: Spigot‑socket with elastomeric gasket—quick, bolt‑free sealing per ISO 2531 socket dimensions.
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Mechanical Joints: Gland‑and‑bolt restraint for fittings and valves, meeting ISO 2531 and AWWA C111 requirements.
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Flanged Joints: ANSI B16.1 or EN 1092‑type flanges enable disassembly and axial-load resistance.
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Field Practices: Trench bedding, deflection limits, hydrostatic testing and chlorination follow ISO 2531 and AWWA guidelines.
Product Series Comparison
| Class | Wall Thickness (mm) | Typical Price (USD/ton) |
|---|---|---|
| K7 | 6.0 | $480 – 530 |
| K8 | 6.0 | $480 – 530 |
| K9 | 6.3 | $250 – 420 |
| K12 | 8.4 (calculated via e=12 × (0.5+0.001 × 200)) | $885 – 895 |
Wall thicknesses per ISO 2531; prices vary by volume, coating and supplier.
International Standards
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ISO 2531 / EN 545 / EN 598: Pipe dimensions, linings and joint performance.
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GB/T 13295‑2019: Chinese standard for DIP, fittings and joints in water/gas applications.
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ANSI/AWWA C105/A21.5, ASTM A674, JDPA Z 2005, BS 6076: Polyethylene sleeving (external corrosion control).
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EN 969: Requirements for gas‑pipeline DI pipes, fittings and accessories.
Advantages
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Exceptional Longevity: 100+ year design life reduces lifecycle replacements.
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High Strength & Toughness: Tensile ≥ 420 MPa withstands surge and external loads.
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Comprehensive Corrosion Control: Cement‑mortar lining, bonded zinc/bitumen coatings, LPS.
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Versatile Joints: Push‑on, mechanical, flanged and restrained systems for diverse site needs.
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Sustainability: Fully recyclable material with low life‑cycle energy use vs. thermoplastics.
FAQ
Q1: How do K classes differ?
They’re thickness classes defined by e=K (0.5+0.001 DN)—K7/K8/K9/K12 yield 6.0/6.0/6.3/8.4 mm at DN200 respectively.
Q2: What corrosion protections are available?
Standard options include cement–mortar lining, zinc/bitumen coatings, loose polyethylene sleeving (ANSI/AWWA C105) and, where needed, cathodic protection.
Q3: What sizes and lengths are offered?
DN 80–2600 mm, typically 6 m laying lengths (5.7 m for container loads) with custom cuts on request .
Q4: Can DIP be used in seismic or high‑load areas?
Yes—restrained joints (e.g., T‑bolt, tie‑rod, ball‑and‑socket types) accommodate ground movement and axial loads for seismic resilience .
Case Studies
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Huntsville Utilities, AL: Journal AWWA study reports $666,999 annual pumping‑cost savings and $17 million PV benefit over 50 years by using DIP vs. PVC.
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Everglades City, FL: Ductile iron with loose polyethylene encasement remained in “excellent condition” after 10+ years in uniquely corrosive soils (resistivity 140–240 Ω‑cm).
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 | ….. |
