The invention relates to a check valve assembly (100) having an inlet (205) and an outlet for medical fluids, comprising a valve body (101), wherein the check valve assembly (100) in an initial state allows a flow of a working fluid and/or a sterilization fluid through the check valve assembly (100) in both directions of flow, that is from the inlet (205) to the outlet and vice versa, and wherein the check valve assembly (100) in an operating state allows only one direction of flow of the working fluid, wherein the check valve assembly (100) comprises a pin-pin-reception connection, which is embodied so that the check valve assembly (100) can be transferred from the initial state into the operating state by applying force on the pin-pin-reception connection and/or by an impression of path on the pin-pin-reception connection.
