Liquid filter and filter element

A liquid filter comprising:

• a filter housing comprising a filter head and a housing cup;
• a filter element comprising a filter medium annularly surrounding a longitudinal axis of the filter element, wherein the filter element comprises an extension part provided with a lock groove;
• a lock device comprising at least one lock means movable radially in relation to the longitudinal axis and arranged at the housing cup, wherein the at least one lock means engages the lock groove in a locked state of the lock device and is disengaged from the lock groove in a release state of the lock device;
• and
• a holder movable between a locked position and a release position, the at least one lock means being guided in the holder,
• wherein the lock device comprises a grip piece configured to move the holder, and wherein the grip piece is movable in relation to the holder,
• wherein the housing cup comprises a drainage opening, and wherein the lock device is arranged at the drainage opening of the housing cup,
• wherein the filter housing further comprises a closure screw configured to close the drainage opening of the housing cup in a mounted state of the closure screw,
• wherein the extension part comprises a nose and a compensation element movable in relation to the nose, and
• wherein the closure screw is coupled to the compensation element in the mounted state.

A filter element for a liquid filter, the filter element comprising:

• a filter medium annularly surrounding a longitudinal axis of the filter element;
• and
• an extension part extending outward from the filter medium axially in relation to the longitudinal axis and provided with a circumferential lock groove, wherein the lock groove comprises a rounded cross section, and wherein the lock groove is configured to:
• be engaged by at least one lock device of a housing cup of a filter housing movable radially in relation to the longitudinal axis in a locked state of the at least one lock device;
• and
• be disengaged by the at least one lock device in a release state of the at least one lock device;
• and
• wherein the extension part comprises a nose and a compensation element movable in relation to the nose;
• and
• wherein a closure screw of the filter housing of the liquid filter is coupled to the compensation element in a mounted state of the closure screw.