All of our covers have a standard load rating of C250 (25 tonnes) and all of our heavy duty D400 (40 tonnes) versions are available.
In the structures of drain and sewer systems, there are also structures for overcoming height differences, inspection chamber, intersection structures, storm water overflow works, infall works (street type drainage) and outfall as well as valve works, besides manholes.
The largest share of the structures of sewer and drain systems goes to manholes to EN 476. For this reason, these and the inspection chamber to EN 476 these are coming more into use.
According to EN 752-1, a manhole is defined to be a chamber with a removable cover on a drain or sewer to permit a personnel to enter.