A docking device for mechanically connecting an upper and a lower container module of a multipart container. The docking device includes an upper docking segment which is fastenable on an opening of the upper container module, and a lower docking segment which is fastenable on an opening of the lower container module. Fluid is configured to move from the upper container module into the lower container module. An upper docking region of an upper channel section and/or an upper docking segment and a lower docking region of a lower channel section and/or the lower docking segment can be arranged in such a way that the fluid flows through an externally leak-tight channel in an open valve body position. An actuating assembly is arranged in the upper channel section and/or in the lower channel section.