A filter element comprising: - a filter medium having an axis and forming a channel extending substantially axially; - a first and a second end plates (5, 6), each end plate covering one axial end of the filter medium and being sealingly mounted on said axial end, the first end plate having an central opening substantially coaxial and in fluid communication with the channel; the filter element being designed to be placed in a filter housing for forming a liquid filtering device, whereby a liquid to be filtered can flow along a liquid path through the filter medium towards the channel and out of the filter element through the central opening, the filter element further comprising a detachable plug whose position can change from an attached position to a detached position, wherein: - in the attached position, the detachable plug is attached to an immobile portion (5, 9) of the filter element and seals the central opening, - in the detached position, the detachable plug is detached from said immobile portion (5, 9) and is movable away from said central opening inside the channel and along the filter element axis to unseal said central opening, up to an end position where the detachable plug is located at a distance from the central opening and where the detachable plug is entirely contained in the channel, characterized in that the channel comprises an inner perforated wall that is realized by a central perforated rigid tube that extends axially between the first and the second end plates (5, 6), in that the central perforated rigid tube comprises at least one guiding surface arranged inside the central perforated rigid tube to guide the detachable plug during its motion from the central opening up to the end position, in that the change of position from the attached position to the detached position of the detachable plug is irreversible, in that said at least one guiding surface is a helical path arranged on an inner surface of the central perforated rigid tube, and in that the detachable plug comprises at least one corresponding guiding element designed to be guided in said helical path during the motion of the detachable plug from the central opening up to the end position. - a filter medium having an axis and forming a channel extending substantially axially; - a first and a second end plates (5, 6), each end plate covering one axial end of the filter medium and being sealingly mounted on said axial end, the first end plate having an central opening substantially coaxial and in fluid communication with the channel; the filter element being designed to be placed in a filter housing for forming a liquid filtering device, whereby a liquid to be filtered can flow along a liquid path through the filter medium towards the channel and out of the filter element through the central opening, the filter element further comprising a detachable plug whose position can change from an attached position to a detached position, wherein: - in the attached position, the detachable plug is attached to an immobile portion (5, 9) of the filter element and seals the central opening, - in the detached position, the detachable plug is detached from said immobile portion (5, 9) and is movable away from said central opening inside the channel and along the filter element axis to unseal said central opening, up to an end position where the detachable plug is located at a distance from the central opening and where the detachable plug is entirely contained in the channel, - in the attached position, the detachable plug is attached to an immobile portion (5, 9) of the filter element and seals the central opening, - in the detached position, the detachable plug is detached from said immobile portion (5, 9) and is movable away from said central opening inside the channel and along the filter element axis to unseal said central opening, up to an end position where the detachable plug is located at a distance from the central opening and where the detachable plug is entirely contained in the channel, characterized in that the channel comprises an inner perforated wall that is realized by a central perforated rigid tube that extends axially between the first and the second end plates (5, 6), in that the central perforated rigid tube comprises at least one guiding surface arranged inside the central perforated rigid tube to guide the detachable plug during its motion from the central opening up to the end position, in that the change of position from the attached position to the detached position of the detachable plug is irreversible, in that said at least one guiding surface is a helical path arranged on an inner surface of the central perforated rigid tube, and in that the detachable plug comprises at least one corresponding guiding element designed to be guided in said helical path during the motion of the detachable plug from the central opening up to the end position.