Patent ID: 7614607

Claim:
A selectively closeable drain connector arranged for mounting to a tank or bag, the drain connector comprising: a plunger including a plunger body having a first closed end, a second open end, a wall with an exterior surface and with an interior surface bounding a hollow core, and a first and a second circumferential sealing element disposed along the exterior surface, the plunger body further defining at least one passage extending from the exterior surface into the hollow core and disposed between the first and the second circumferential sealing element; and a drain flange defining an aperture adapted to receive the plunger, the aperture being bounded by an inner surface adapted to sealingly engage the first and the second circumferential sealing element when the drain connector is in a closed state, and to sealingly engage the second circumferential sealing element when the drain connector is in an open state; wherein any of the plunger and the flange is adapted to move relative to the other; and wherein the drain connector is characterized by any one or more of the following: (i) the drain flange has a radially extending flange lip adapted for placement against a bottom wall of said tank or bag, and the first sealed end of the plunger is disposed substantially flush against an upper surface of said radially extending flange lip when said drain connector is in a closed state; and (ii) a portion of the plunger is arranged to travel into an interior volume of said tank or bag when said drain connector is in an open state.