Cement manholes are not just simple "pipeline junctions"; they are "multi-functional hubs" that ensure the stable operation of the drainage system. Their core role is manifested in the following four aspects:

1. Inspection and Maintenance: As the only access point for personnel (or equipment) to enter the underground pipeline network, it facilitates regular checks for pipeline sedimentation, damage, leaks, and other conditions, serving as the sole entry for the "physical examination" of the pipeline system.

2. Clog Removal and Drainage Clearance: In the event of pipe blockages, sedimentation and drainage equipment (such as high-pressure water jets, dredging claws) can be deployed through inspection wells to quickly clear debris within the pipe, restoring smooth drainage.

3. Flow and Water Quality Monitoring: Some municipal manholes are pre-equipped with monitoring interfaces for the installation of flow meters and water quality sensors, enabling real-time tracking of drainage flow and pollutant concentrations, thereby aiding in the refined management of the pipeline network.

4. System Connection and Direction: At nodes such as pipe bends, diameter changes, gradient variations, and branch connections, smooth transitions between pipes of different sizes are achieved through manholes. Simultaneously, water pressure and air flow within the pipeline network are balanced to prevent damage to pipes due to pressure fluctuations.