Ductile iron manhole covers can be classified in various ways, such as load-bearing capacity, structure, and appearance. Their load-bearing capacity levels are divided into three grades: B125, C250, and D400, corresponding to the GB/T 23858-2009 standard.
Different usage locations have specific requirements for the load-bearing capacity of drainage manhole covers: For areas such as green belts, sidewalks, and non-motorized vehicle lanes, the minimum requirement is a B125 type drainage manhole cover; for areas within 0.5m of the curb on both sides of the road, the minimum requirement is a C250 type drainage manhole cover; for urban main roads, highways, high-grade highways, expressways, etc., the minimum requirement is a D400 type drainage manhole cover.
According to structure, they can be divided into direct-bearing manhole covers and anti-settlement adjustable manhole covers. Anti-settlement adjustable manhole covers are suitable for asphalt pavements, while direct-bearing manhole covers are suitable for concrete pavements, brick pavements, green belts, etc. Based on appearance, manhole covers can be categorized into standard, landscape, and infill types. Standard manhole covers are generally recommended for urban roads. In areas with specific landscaping requirements, manhole covers can be custom-designed based on engineering requirements, cultural factors, and aesthetic considerations, and landscape or infill types are preferable.
The manhole cover system consists of the cover body, a ductile iron load-bearing frame, and an aging-resistant rubber sealing gasket.
Product shapes are available in round and square formats. Round manhole covers are designed for even stress distribution to prevent falls, while square manhole covers are equipped with a rainwater drainage structure.
