Filter element, filter head, and filter system

A filter element for releasable connection with a filter head, said filter element having an elongate shape with a longitudinal axis;

• the filter element comprising:
• (a) a first end cap defining a first open aperture;
• (b) a tubular construction of filter media defining an open filter interior and having first and second opposite ends, the first end being secured to the first end cap whereby the first open aperture is in communication with the open filter interior;
• and
• (c) an axially extending neck, surrounding said first open aperture, having an outer radial surface and an inner radial surface;
• wherein said filter element comprises a first linear to rotary motion conversion element, arranged to engage with a second linear to rotary motion conversion element on a valve element of said filter head so as to impart, when said filter element is moved linearly towards said valve element in a direction along said longitudinal axis, a rotational movement onto said valve element;
• the first linear to rotary motion conversion element comprising a plurality of helical ribs.