What's the top cover on the drain?
In addition, the Cantonese name for manhole covers is manhole covers. Because Guangdong people called sewer wells for manholes, so known as manhole cover manhole cover.
In the manhole, general use to indicate the underground pipes and pipe support units and telephone and other information.
City construction will have a lot of underground pipelines, such as sewer, underground gas pipeline, pipeline, pipeline, tap water power communication pipeline, pipeline and other defense, these pipes every once in a while to have a exit to the surface, from the pipeline to the ground in this section is called the manhole, manhole is flush with the ground, so need a lid, cover for manhole cover, manhole cover is called. The manhole cover made of common reinforced concrete, metal, plastic and other materials to strengthen, in the shape of circular and square.
