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 . <EOS>