In wastewater systems, many manholes and special structures are required for inspection, control and merging. In the PKS profile sewer pipe system, manholes and special structures with different functions are therefore available in polyethylene (PE) and polypropylene (PP). Thanks to the excellent properties of these materials, the sewer pipes can be continuously welded, and different behaviour — such as the reaction to settlements — is taken into account uniformly for the complete system.

PKS manholes usually consist of a PE or PP base, supplemented with precast concrete parts according to DIN 4034 for continuation to ground level. The mounted reinforced concrete cover plate bears the live loads directly into the manhole. The bottom part in contact with wastewater and groundwater is made of corrosion-resistant PE or PP. Depending on the load, the manhole can also be made entirely of PE 100 or PP-R. The manholes are provided with an access opening and mounted safety ladders.

PKS manholes feature a heating-coil welding socket as a spigot end, as well as a spigot end for direct connection to the PKS pipes. Like the PKS pipes, they are characterised by a light-coloured, inspection-friendly inner surface, low weight and very low roughness. For manholes with large traffic loads, a reinforced concrete load distribution plate should be provided towards the top; it transfers the traffic loads into the ground so that the full axial forces no longer act on the shaft.