For the success of a project, it is important to know how to choose the right manhole cover, made of PVC, concrete or other material. The manhole cover must always be in the class appropriate to the place of installation and therefore to the stress it will be subject to. If in doubt you must use a device of a stronger class than that strictly foreseen.
The designer must also choose a size appropriate for the clearance to guarantee safe access to the manhole cover with manhole. As far as the shape is concerned, generally the Italian market of grids and underground works have the widespread presence of square shapes (starting from the outside dimension of the 300×300 frame), rectangular and circular shapes. Fuel service stations and purifying plants have manhole covers with outside dimensions exceeding 1 m.
Furthermore, before installation, the following indications must be checked: