Sewer shafts are made of high-density polyethylene using spiral winding of polyethylene and polypropylene. Both sewer shafts and pipes have identical material properties in terms of chemical influences and all other types of resistance to both the internal content and external pressures and loads.
Their interior is smooth, while a ring is spirally wound over the outer wall, but depending on the need, the so-called sandwich profile where the ring is located in the middle between the inner and outer edge can be made.
GHIBLIPLAST plastic manholes are made with open or closed kinet, depending on the project requirements, have welded ladders on the vertical wall and are additionally loaded in the lower zone as protection against impact of groundwater during installation (part of the manhole below the kinet is filled with sand or concrete as a weight due to the consequences of lifting during assembly and backfilling).
By choosing GHIBLIPLAST sewer shafts and their extrusion welding on the outside or inside (depending on the diameter of the pipe), it is very effective to neutralize the harmful impact of high levels and groundwater pressure on the pipeline and in most cases where the pipe bottom is below river and sea levels. In places with active flows, the choice of such a pipeline is made, precisely because it guarantees a high percentage of impermeability in relation to other types of joints (concrete-PVC, rubber seal...)
The advantages compared to conventional concrete manholes are: low mass of the manhole which enables much faster installation and manipulation as well as lower transport costs, absolutely waterproof and non-porous, have great rigidity and elasticity so that the manhole will not crack when moving the ground. GHIBLIPLAST plastic manholes have a long service life of over 50 years. Production of these products (plastic pipes and shafts) includes installation in the field, ie. pipeline construction.