Abstract: A press plate, actuated by a cylinder, has a press ring affixed to its lower surface. The press ring is dimensioned to fit on the lid of an open head drum. Magnets positioned on the lower surface of the press plate hold a split closing ring in position encircling the press ring. Horizontally actuated closing ring expanders are pivotally mounted in a plurality of slots spaced about the circumference of the press ring. A plurality of pins, positioned above the split closing ring, extend through the press plate. A plurality of clamp levers, having bottom ends positioned below the press plate and externally of the split closing ring and upper ends connected to actuators mounted on top of the press plate, are pivotally mounted to and extend through the press plate. A split closing ring encircling the press ring is urged outwardly by the ring expanders as the press plate and press ring move downward, compressing a sealing gasket between the lid and drum.