HUBER Storm Screen ROTAMAT® RoK2 for Storm Water Discharges

Automatically cleaned screen for solids retention in storm water tanks and overflows

  • Efficient solids separation
  • Continuous automatic screen cleaning
  • Defined solids removal
  • For discharges with limited upstream head possibilities
  • Sturdy, low-maintenance stainless steel design

The inverted upward flow storm screen HUBER ROTAMAT® RoK2 belongs to a group of fine screens designed for high flow rates at an extremely low hydraulic resistance.

During and after storm events large amounts of debris are discharged to streams, rivers and lakes through storm water overflows of combined and sanitary sewer systems. Particularly endangered receiving water courses and nature preservation areas require more extensive measures concerning the treatment of storm water.

The inverted upward flow storm screen ROTAMAT® RoK2 is the ideal solution for this task, whether for new structures or refurbishment. Two-dimensional screening guarantees a very high solids retention combined with automatic, gentle cleaning of the perforated plate.

RoK2 screens are horizontally installed before the downstream side of overflow weirs. A screw flight is mounted on a half cylinder of perforated plate. As the storm water flows down to up through the horizontal perforated half-pipe of the screen trough the solids are retained. A screw, with a brush attached on ist flights, rotates within the semi-circular screen trough. It cleans the screen and pushes the screenings gently towards the end of the trough. At the end of the trough, the screenings are returned into the sewer and carried to the wastewater treatment plant. During storm conditions the screen is automatically started and then works fully automatically.


The screen is installed in front of the weir overflow. This design results in the following favorable benefits:

  • Optimal solids retention by means of two-dimensional screening (perforated plate)
  • Screenings remain on the polluted water side
  • No downstream impact on the screen efficiency
  • For problem-free retrofitting into existing structures
  • The perfect solution for discharges with limited upstream head possibilities
  • Possibility of completely submerging the screen