An apparatus, system, and method are disclosed for draining a liquid. An inner drain body is disposed on a container, with an inner liquid outlet in its lower portion, and an air inlet above and at a radial offset from the inner liquid outlet. An outer drain body is disposed around and below the inner drain body, and is adjustably coupled to the inner drain body. An outer liquid outlet is disposed in the outer drain body. A lower seal is disposed below the inner liquid outlet and between the inner drain body and the outer drain body, engaging a lower sealing surface. An upper seal circumscribes the inner liquid outlet and the air inlet, and is disposed between the inner drain body and the outer drain body, engaging an upper sealing surface that extends further beyond the upper seal than the lower sealing surface extends beyond the lower seal.