The specifications and models of manhole covers

The specifications and models of manhole covers mainly include three categories: size, load-bearing grade and material, as detailed below:

I. Dimensions and Specifications
Round manhole cover (ring) ‌
Common diameters: 500mm, 600mm (the most commonly used), 700mm, 800mm, 1000mm. Large manhole covers can reach up to 1500mm.
Square manhole cover ‌
Common sizes: 400×600mm, 600×600mm (commonly used), 750×450mm.
Special size ‌
Anti-settlement manhole covers: 700×900mm, 800×1000mm.
Ii. Load-bearing Grade (National Standard GB/T 23858-2009)

It is divided into six levels according to load capacity, corresponding to different application scenarios:

A15 class ‌ (15kN/1.5 ton) : No-motor vehicle areas such as green belts and sidewalks.
B125 class ‌ (125kN/12.5 ton) : sidewalks, non-motorized vehicle lanes, car parking lots.
C250 class ‌ (250kN/25 ton) : residential areas, back streets and alleys, light motor vehicle lanes.
D400 class ‌ (400kN/40 ton) : urban main roads, expressways.
E600/F900 class ‌ (600-900kN/60-90 tons) : freight stations, terminals, airport runways.
Iii. Material Types
Ductile iron ‌ : high strength, corrosion resistance, suitable for motor vehicle lanes (D400 and above).
Composite material ‌ : lightweight, anti-theft, load-bearing capacity 10-25 tons (B125-C250 grade), suitable for sidewalks, parks.
Steel fiber reinforced concrete ‌ : Compressive strength ≥15MPa, density about 500kg/m³, for medium load scenarios.
Stainless steel ‌ : Beautiful and corrosion-resistant, often used in landscape engineering.
Iv. Other Key Parameters
Physical properties ‌ : Elastic modulus about 1000 mpa, flexural strength 22MPa, impact strength 10J/m², water absorption ≤1%.

Note ‌ : When selecting, match the load requirements of the application scenario (e.g., select C250 for a small area) and wellhead size to avoid safety hazards caused by mismatch of specifications.