In daily life, we often see round manhole covers. Why are they designed to be round? There are several reasons:

1.Geometric characteristics

• Equal diameter: The diameter of a round manhole cover is fixed. No matter how it is rotated or placed, its diameter remains unchanged. This means that it will not fall into the well from the diagonal or other angles of the wellhead. The diagonal length of a square manhole cover is greater than the side length. If it is improperly placed or impacted by external forces, it may fall into the wellhead from the diagonal direction, causing safety hazards.
• Uniform force: The circle can evenly disperse the pressure from above in all directions. In contrast, square or other polygonal manhole covers will be subjected to greater stress concentration at the corners, which is prone to rupture and damage in these parts, affecting the service life and safety of the manhole cover.

Construction and use

• Easy to install and roll: During the installation process, the round manhole cover does not need to be precisely aligned like the square manhole cover. It only needs to be placed on the wellhead, which is easier and faster to operate. In addition, the round manhole cover can be transported by rolling, saving manpower and material resources and improving construction efficiency.
• Good sealing: The contact between the round manhole cover and the wellhead is circular, which can better fit with the wellhead, forming a good sealing effect, effectively preventing rainwater, sewage, debris, etc. from entering the well, and also reducing odor and noise transmission.

Aesthetics and standardization

• Good visual effect: The circle has a simple and smooth appearance, giving people a harmonious and beautiful feeling, and it is easier to blend with the surrounding environment. In contrast, the square manhole cover may appear stiff.
• Standardized production: In large-scale production and manufacturing, the mold design and manufacturing of the round manhole cover are relatively simple, and the production process is more standardized and standardized, which is conducive to improving production efficiency, ensuring product quality and reducing costs.