Filter system and filter element

A filter system for a liquid medium to be filtered, the filter system comprising:

• a filter housing comprising
• a housing pot and
• a housing cover,
• wherein the housing cover is configured to be screwed by a screwing movement onto the housing pot or into the housing pot to close off the housing pot,
• wherein the housing pot comprises
• a drainage channel with
• a drainage opening arranged at a bottom of the housing pot for draining the liquid medium;
• a filter element comprising
• a bottom end disk,
• wherein the bottom end disk comprises
• a closure element formed as a closure plug on the bottom end disk and projecting axially outwardly, the closure plug arranged off-center at the bottom end disk relative to a longitudinal axis of the filter element,
• wherein the closure element, in a predetermined installation position of the filter element in the filter housing, extends seal-tightly across the drainage opening of the drainage channel or extends seal-tightly into the drainage opening of the drainage channel;
• wherein the bottom end disk of the filter element further comprises:
• an annular socket having an annular outer wall having a first axial end secured onto the bottom end disk, the annular socket projecting axially outwardly from the bottom end disk to an axially outer end face forming a free rim of the annular socket, wherein the free rim of the axial outer end face is arranged in plane parallel to the bottom end disk,
• wherein the annular socket has a cutout extending radially through the annular outer wall, the cutout extending axially from the free rim in a direction towards the bottom end disk;
• wherein the housing pot further comprises
• a pin-shaped positioning aid formed on a bottom wall of the housing pot and projecting axially towards the bottom end disk, the pin-shaped positioning aid sized and aligned radially with the cutout to be engageably receivable into the cutout;
• wherein the filter element is configured to move by a screwing movement of the housing cover in an axial direction toward the drainage opening and to rotate together with the housing cover about the longitudinal axis of the filter element until the pin-shaped positioning aid engages the cutout of the annular socket and locks the filter element relative to the housing pot in a predetermined rotational position,
• wherein in the predetermined rotational position the closure element is axially aligned relative to the drainage opening;
• wherein the filter element is configured to move by the screwing movement of the housing cover in the axial direction into the predetermined installation position of the filter element in the filter housing.