Drainage cups and cups with bottom ring drainages promote the run-off of the rinsing water in inclined position in rinsing baskets and rinsing lines. Hollow parts such as cups, bowls and cups generally always have a slightly concave bottom, in which residual water tends to collect during rinsing. When the dishes are removed, the residual water drips onto the compartment below or runs down the hollow part itself. This is not only annoying, but also prevents a good flushing result.
This undesirable effect is prevented by the so-called drain channels or drain openings, which are called drainages in the technical jargon. However, these are relatively pointless if the hollow part is placed completely straight on the basket, since the remaining rinsing water cannot run off when the basket is placed straight. A combination of drainage and slope is therefore required. Whether drainage cups actually have a better drainage value than conventional hollow parts without drainage is left to the opinion of the observer.
