The Cultural Significance of National Manhole Covers
(vi) Odor Control: Manholes can emit unpleasant odors due to the presence of gases. To minimize odors in residential spaces, consider implementing odor control techniques, such as installing odor-reducing inserts or chemical treatments.
The design and implementation of an 18-inch manhole cover are far more complex than one might assume. Typically made from materials like cast iron or composite materials, these covers are engineered to withstand significant load and pressure. Their circular shape is not merely aesthetic; it is a practical decision. The round design prevents the cover from falling through the opening, regardless of how it is positioned—something that cannot be guaranteed with square or rectangular covers.