Toilet Bowl/Pan

The bowl or pan of a toilet is the receptacle that receives bodily waste. A toilet bowl is most often made of porcelain stainless steel or composite plastics. These are mounted in any one of three basic manners: above-floor mounted by a pedestal, wall mounted or cantilevered or in-floor mounted.

Most incorporate an 'S' shaped water-way so that the water-way will naturally fill up with water, each time it is flushed, thus creating the siphon action. To flush the toilet the user activates a flushing mechanism which pours a large quantity of water quickly into the bowl. This creates a flow large enough to purge the bowl's water-way of all air, thus causing the bowl to empty rapidly due to the siphon action that has been created. This flow stops as soon as the water level in the bowl drops below the first bend of the siphon, allowing air to enter the S-pipe to break the column of liquid and to halt the siphon action.

WIKIPEDIA ENTRY FOR FLUSH TOILET.