To meet the demands for installation equipment, routine repairs, and maintenance, inspection wells are set at regular intervals along the pipeline burial direction during construction. The inspection well cover (also known as the general well cover and covers for various underground pipeline inspection wells and storm drain gratings) is the primary matching product for the inspection well. Its function is to bear weight, close, and open the inspection well. It can withstand high-speed traffic flow from vehicles and also prevent the entry of vehicles, pedestrians, and foreign objects, ensuring the normal operation of underground pipelines and equipment.

1. As per the differences in distribution planning: a. Underground pipeline manhole covers for urban shared road traffic facilities b. Underground pipeline manhole covers for units and residential communities

2. Differentiated by Ownership a. Manholes owned entirely by various pipeline companies b. Manholes owned entirely by the users

3. By pipeline type differences: stormwater, sewage, potable water, gas, hot gas, electricity supply, communication, cable TV, traffic signaling lines, etc., these types of manholes are commonly set in the underground pipeline types of road engineering projects.

4. By Load-Bearing Differences a. Heavy Duty Manhole Cover: Used for municipal road traffic and heavy vehicle passage b. Light Duty Manhole Cover: Used for shared road traffic and light vehicle passage

5. Material Differences: a. Metal Manholes: Cast Iron, Ductile Iron, Bronze Manholes, etc. b. High-Strength Steel Fiber Reinforced Cement Concrete Manholes (cement-based composite materials) are classified into four levels: A, B, C, and D. A-grade steel fiber concrete manholes are used for special routes and locations such as airports. B-grade steel fiber concrete manholes are for urban roads, highways, and parking lots where motor vehicles travel and park. C-grade steel fiber concrete manholes are for slow lanes, residential community pathways, and sidewalks. D-grade steel fiber concrete manholes are for green belts and alleys where motor vehicles cannot travel or park. c. Recycled Resin Manholes (recycled resin-based composite materials) d. Polymer Matrix Composite Manhole Covers, etc.