Device For Controlling A Fluid Flow

A device for controlling a fluid flow between a first pipe connection and a second pipe connection, comprising a housing, a valve body which can move in the housing in a direction of movement under the influence of pressure in the first pipe connection and/or the second pipe connection and possibly a spring and which housing has a first annular sealing surface relative to which a second annular sealing surface of the valve body can move for closing or controlling the fluid flow through an annular gap having two more or less parallel walls which are formed by the annular sealing surfaces, characterized in that one of the annular sealing surfaces is adaptable and can create an annular gap with a changed difference in the distance to the other annular sealing surface at a first inner diameter and a first outer diameter.