An extensive range of possible downcomer geometries is available for all tray constructions. In principle one-, two- and four-flow designs as well as reverse flow geometries can be calculated. The downcomers can be implemented as segments ("chordal"), recessed, multi-chordal, cartridge or tube.

The downcomer weir can be notched, blocked or swept-back, the inlet can be carried out simply, as recessed seal pan with an inlet weir (simple, notched or blocked) or lip.