A screening device for eliminating balls (6) for cleaning the tube of a heat exchanger, condenser or the like from a coolant line (7) comprises a screen (2) located in the outlet area of the heat exchanger, able to cover the free cross section of the coolant line (7) for collecting the balls (6) and progressively restricting the free cross section for the coolant for the collection of the balls (6) in the cooling medium flow direction and a removal line (3), positioned in the flow direction of the cooling medium behind the screen (2) in such a way that the balls (6) collected by the screen (2) are passed into the removal line (3) and leave the coolant line (7) via the removal line (3). For obtaining a less expensive construction for the screening device the screen (2) is fixed to the wall (7a) of the coolant line (7).
