elements 24 have truncated cone like transitions which on the one side lies on valve seat 26 in the closed state of the valve element 31 and in relation to which a compression spring 30 is reciprocally centered the construction of the valve element 31 provides for a valve disk 32 made of plastic in which the lead off cross sections 29a 29b are located and a leakage slit 28a 28b is assigned to each closing element 24 retention fingers formed as one piece with the valve disk 32 project axially out of the valve disk 32 to serve as guide elements 33 these guide elements 33 are arranged at a distance to one another around the closing element 24 to guarantee an exact guidance of the closing element 24 which form the step valves 25a 25b the damping element 41 furthermore includes the housings 27a 27b located on both sides of the valve disk 32 which are surrounded by a sleeve 34 to create a unitary assembly and on the end faces is joined in a form locking manner with the housing 27a 27b fig6 clarifies in a diagram the course of flow through resistance of the step valve 5 or 15a 15b of the invention in comparison with a conventionally constructed ball valve in a one way valve.