Round manhole covers offer superior safety solutions compared to their square counterparts. Since a round cover cannot fall through its circular opening, it eliminates the risk of accidental drops. This is particularly important in busy urban areas where pedestrians, cyclists, and vehicles share the space above. The uniform shape of a round cover also helps to distribute the weight evenly, reducing the likelihood of cracking or breaking under pressure from heavy traffic.
2. Lubrication Apply lubricant to the stem and threads to ensure smooth operation and prevent seizing, especially in older valves.
The third stage is that after 2008, with the emergence of new materials and new installation technology, the types of new manhole covers mainly include FRP manhole covers, steel fiber manhole covers and composite manhole covers, etc. These manhole covers have better anti-corrosion and anti-theft effects than cast iron material types, and the sound of human trampling or car rolling is smaller.