Why are most manhole covers round – Round manhole covers

Why Are Manhole Covers Round?

Circular manhole covers are preferred in urban drainage systems because they have many superior advantages over other shapes. Here are the reasons why the majority of manhole covers are round:

• Even force distribution: The circular shape helps distribute force and weight evenly across the entire surface of the manhole cover. When vehicles or heavy objects pass over, the pressure is evenly distributed, helping the cover avoid deformation or damage caused by concentrated pressure at a single point.
• Easy to rotate and install: Circular manhole covers can rotate freely within the manhole frame, making installation and maintenance easy. Thanks to this feature, there is no need to worry about which direction to rotate the cover when putting it back.
• High durability: With a round design, the manhole cover has high load-bearing capacity and ensures sturdiness. This allows the manhole cover to withstand heavy loads from vehicles and impacts from the environment such as temperature, ground pressure, and other weather factors.
• Saves production costs: The manufacturing process for circular manhole covers is often simpler and less expensive than for covers of other shapes such as square or rectangular. This helps reduce production costs and product completion time.
• High sealing performance: The circular shape creates a uniform gap between the cover and the manhole frame, ensuring water-tightness, preventing dirt, insects, and odors from the sewer system from escaping. This sealing property is very important in maintaining a clean environment.
• High aesthetics: Circular manhole covers have a simple and refined design, easily harmonizing with the surrounding environment without negatively affecting the urban landscape. This makes them popular in public areas.
• Stability: The circular shape provides better stability when placed on uneven surfaces. A round manhole cover is not easily flipped or moved, even when the road surface is not flat.
• Compliance with industry standards and regulations: Circular manhole covers often comply with industry standards, ensuring consistency and compatibility with various drainage systems.

Although circular manhole covers are common, there are still special cases where square or rectangular manhole covers are used, depending on the project requirements. However, the circular manhole cover is still preferred due to its convenience, flexibility, and good load-bearing capacity.