Calming shafts are used in wastewater systems to reduce the flow rate of waste water through the pipeline. Speed reduction is achieved by waste water entering pane from the side and creates roundabout at shaft walls (calms down) and continues to flow through the outlet pipe.

It is used for gravity drainage water from household, rainwater and wastewater from industrial plants. Inspection shafts allow ventilation, cleaning, maintenance, and access to sewage pipes.
The most common ones are semi prefabricated circular manholes, which are extremely waterproof, light weight and easy to install, but also very affordable.


  • Bosnian and Herzegovinian product,
  • Long lifespan,
  • Not sensitive to low and high temperatures,
  • High static load,
  • Long-term stability and low wear,
  • Excellent chemical resistance,
  • Wide product range,
  • Industrial production,
  • Easy maintenance.


Shafts are vertical pipes with pipe connections from the sewage system at the bottom and the inlet with a lid on top. Pipe connection at the bottom of the water to the dam, which directs the flow of water and prevents the deposition of silt on the bottom of the shaft.


Inspection shafts can be applied as a transit or non-transit. When installing shafts made of polymeric materials there are no restrictions. On the lawns and areas intended for pedestrians and cyclists non-transit shafts are installed. These shafts have less load and lid with a concrete ring.
Transit area shafts can endure axial loads of 600 KN (transit area of the cars and the heaviest trucks), or airport shafts up to 900 KN. Cover and relief ring on the top of the pane transfer load of the vehicles to the bulk material by the shaft.