Grease traps are used in homes and commercial kitchens to trap grease and oils before they enter the sewage system. There are many types and sizes of grease traps but they all work basically the same way. The trap is connected to the top and the water exits into the drain. These grease traps have to be emptied and cleaned regularly to prevent smells and to keep the trap from getting full. How often this cleaning needs to be done depends on how large the grease trap is and how much grease is entering the drain. In this video you see how this particular grease trap functions.