A refrigerated case comprising: a body having: a refrigerated compartment; an air flowpath; a lower wall below the air flowpath; and a drain pipe protruding from the lower wall and having a lower outlet; a refrigerant flowpath; and a refrigerant-air heat exchanger along the refrigerant flowpath and within the air flowpath, wherein: the body further comprises a water trap vessel having: an upper end; a lower portion; at least one vessel outlet; and a segmented rim flange; wherein: the upper end is secured to the base; the lower portion surrounds the drain outlet; the at least one vessel outlet is above the drain outlet, characterised in that a plurality of slots both segment the flange and form the at least one vessel outlet, with the segmented rim flange having segments that are separated by the slots; the body comprises a plurality of threaded fasteners engaging an underside of the flange along respective said segments to vertically and laterally retain the water trap vessel and permit removal of the vessel via a rotation of the vessel; and the body further comprises an additional threaded fastener between a respective pair of said segments. a body having: a refrigerated compartment; an air flowpath; a lower wall below the air flowpath; and a drain pipe protruding from the lower wall and having a lower outlet; a refrigerant flowpath; and a refrigerant-air heat exchanger along the refrigerant flowpath and within the air flowpath, a refrigerated compartment; an air flowpath; a lower wall below the air flowpath; and a drain pipe protruding from the lower wall and having a lower outlet; a refrigerant flowpath; and a refrigerant-air heat exchanger along the refrigerant flowpath and within the air flowpath, wherein: the body further comprises a water trap vessel having: an upper end; a lower portion; at least one vessel outlet; and a segmented rim flange; an upper end; a lower portion; at least one vessel outlet; and a segmented rim flange; wherein: the upper end is secured to the base; the lower portion surrounds the drain outlet; the at least one vessel outlet is above the drain outlet, characterised in that a plurality of slots both segment the flange and form the at least one vessel outlet, with the segmented rim flange having segments that are separated by the slots; the body comprises a plurality of threaded fasteners engaging an underside of the flange along respective said segments to vertically and laterally retain the water trap vessel and permit removal of the vessel via a rotation of the vessel; and the body further comprises an additional threaded fastener between a respective pair of said segments. the upper end is secured to the base; the lower portion surrounds the drain outlet; the at least one vessel outlet is above the drain outlet, characterised in that a plurality of slots both segment the flange and form the at least one vessel outlet, with the segmented rim flange having segments that are separated by the slots; the body comprises a plurality of threaded fasteners engaging an underside of the flange along respective said segments to vertically and laterally retain the water trap vessel and permit removal of the vessel via a rotation of the vessel; and the body further comprises an additional threaded fastener between a respective pair of said segments.