With the development of social modernization, the beautification of urban construction is particularly prominent. The old well cover on the ground is gradually replaced by the invisible well cover because of its old and cumbersome style, which is not easy to repair. The installation part of the invisible well cover is integrated with the whole ground and is not easy to be stolen. The concealed well cover can be made of galvanized steel plate or stainless steel plate. The main structure of the inner and outer frames is bent into "L" shape and welded at one time. The inner frame can be made of welded steel bars, which can strengthen the strength and stability of the inner frame and effectively attach the filled mortar. Because of its compact structure, better bearing capacity and stability, this structure has been widely used in many occasions, such as community road, street road and so on.

The design of invisible well cover is to ensure the smooth passage of the disabled and improve the overall landscape of the sidewalk. It can "recessive" the municipal public pipeline inspection well on the sidewalk and design the structure of invisible well cover in detail.

The invisible well cover is composed of top steel trough and steel grid plate. During installation, it is equipped with embedded parts composed of steel frame. Invisible well cover 1 is suitable for square well with side length L < 800mm or round well with diameter r < 800mm; invisible well cover 2 is suitable for cable well or cover well with width l > 800mm. During manhole cover maintenance, the concealed manhole cover shall be placed as smoothly as possible to avoid reverse buckle or side standing.