Ductile Cast Iron Standard Round Manhole Cover  

 I. Structural Design  

• Circular Structure: Ensures uniform stress distribution, minimizing deformation or fracture risks caused by vehicular loads.  

• Anti-Displacement Design: Utilizes hinge connections or three-point locking mechanisms (e.g., spring locks, anti-theft bolts) to prevent cover displacement or theft.  

• Anti-Slip Treatment: Surface features cross grooves, fish-scale patterns, or raised dots, achieving a friction coefficient ≥0.6 for superior slip resistance in rain or snow.  

• Custom Markings: Embossed identifiers (e.g., zone codes, ownership labels like "Power" or "Sewage," and load ratings) streamline management and maintenance.  

• Noise Reduction: Rubber gaskets or nylon bushings reduce cover-frame impact noise by 10–15 dB.  

 II. Core Advantages  

1. Ultra-High Load Capacity  

•    Compressive strength of 400–600 MPa, capable of supporting heavy trucks and fire engines (e.g., D400 grade: 40-ton load), ideal for highways, ports, and high-traffic zones.  

•    Exceptional impact resistance, passing EN 124 drop-weight tests without fracture, outperforming composite materials in safety.  

2. Durability and Cost Efficiency  

•    Wear resistance 3x higher than standard steel, with a lifespan exceeding 30 years. Lifecycle costs are lower than composites (no frequent replacements required).  

•    Minimal maintenance: Periodic recoating of anti-corrosion layers suffices; no specialized cleaning or rust prevention needed.  

3. Anti-Theft and Safety  

•    Three-point locks or hinges deter theft, requiring specialized tools for access, reducing theft rates by 80% compared to traditional gray iron.  

•    High-density material (7.3 g/cm³) lacks scrap value, eliminating theft incentives.  

4. Environmental Adaptability  

•    Operates in extreme temperatures (-40°C to 350°C), resistant to freeze-thaw cycles, suitable for polar, tropical, and humid climates.  

•    Anti-corrosion coatings (e.g., zinc spray + asphalt) withstand soil and groundwater corrosion (pH 5–9), extending service life.  

5. Standardization and Compatibility  

•    Uniform dimensions (common sizes: φ600 mm, φ700 mm) ensure compatibility with existing frames, minimizing retrofitting costs.  

•    Customizable surface textures or markings meet municipal management needs.  

 III. Application Scenarios  

1. Municipal Roads  

•    Stormwater/sewer covers (D400 grade) for urban arteries and highways, enduring repeated heavy-vehicle loads.  

•    Bridge expansion joint covers, resistant to dynamic loads and fatigue.  

2. Industrial and Transportation Hubs  

•    High-impact zones in ports, logistics parks, and rail track inspection pits, protecting underground utilities.  

3. Public Facilities  

•    Emergency covers for fire lanes and airport runways, ensuring rapid access during crises.  

•    Upgrading aging communities by replacing fragile gray iron or concrete covers.  

4. Special Environments  

•    Inspection pits for high-temperature steam pipelines, outperforming composites in heat resistance.  

•    Corrosion-resistant coatings delay rust in rainy or humid regions.  

 IV. Certifications and Standards  

International Standards:  

•   EN 124 (European load classification), ASTM A536 (U.S. material standard).  

Chinese Standards:  

•   GB/T 23858-2009 Manhole Covers

•   CJ/T 511-2017 Ductile Iron Manhole Covers

•   GB/T 19426-2018 *Ductile Iron Manhole Covers for Roads and Bridges (primary national standard, specifying models, dimensions, installation orientation, load capacity, anti-slip/anti-explosion performance, corrosion resistance, etc.).  

•   CJJ/T 122-2016 *Code for Design of Urban Road Drainage Engineering.  

• Certifications: CE Marking (EU), ISO 9001 Quality Management, SGS Corrosion Resistance Reports.  

Product Specifications:

• Size Range: φ300–φ1000  

• Load Classes: C250–E600