Valve arrangement for ensuring different amount of medium flow-through comprising at least two chambers (6,7) separated by a limiting wall (3) provided with a through-opening (1). An insertion piece (2) in the through-opening (1) is able to move transversally and the cross-section of its elongated middle portion (4) corresponds to that of the through-opening (1). At least at one end of the insertion piece (2) a closing head (5) is provided. A form-fitting (8) between the closing head (5) and the limiting wall (3) ensures a first closed state thereby a first amount of flow-through from a chamber (6) being on one side of the through-opening (1) to the chamber (7) being on the other side of it when the longitudinal movement of the insertion piece (2) is limited as the closing head (5) abuts against the limiting wall (3) at the through-opening (1).