In accordance with aspects of the present invention, a door mechanism is provided. A door mechanism according to some embodiments of the present invention includes a door that includes a sealing part, an arm connected to the sealing part, and a pivot part connected to the arm, the door rotating around a pivot axis at the pivot part; and a lever, the lever engaging the door at the pivot part such that the lever opens the door when engaged but is not affected when the door is opened without the lever.