The Handle
Bowl Siphon
Once the flush valve has been activated, the siphon bowl at the bottom of the toilet is also opened and sucks any matter inside the toilet bowl out through the plumbing. At the same time, a little over two gallons of water (depending on the toilet) rushes into the bowl to help clean any excess residue off the sides of the bowl and to assist in the evacuation of matter from the bowl. The flush valve resets after about three or four seconds.
Water Tank
The water from the flush valve comes from a water tank located in the back of the toilet. As the water rushes out of the tank, a small float ball lowers and activates the refill valve.
Refill
Once the refill valve has been triggered, water from plumbing pipes attached to the toilet begins to refill the water tank. As the water tank levels increase, the float ball begins to float again. Once the floater reaches a specific level inside the tank, it automatically triggers the refill valve to shut off.
Overflow Tube
With a commercial toilet, the refill valve may not trigger. When this is the case, an overflow tube is present that can take care of any extra water from the toilet running. In most cases, this will keep the toilet tank from overflowing and flooding the bathroom.
Unique Features
Commercial toilets have unique features that are not often found in home versions of the same models. Most commonly, a commercial toilet will have a much greater force behind the bowl siphon to add an extra layer of prevention against clogs. Some commercial toilets also get rid of handles all together and employ motion sensors that automatically flush the toilet a specified amount of time after motion is detected. This ensures that the toilet will be flushed, and also helps increase the level of sanitation.
Shut-Off Valve
If for some reason there is a clog, a shut-off valve is located at the base of most commercial toilets. Turning this valve to the "off" position will turn off all water to the toilet and keep the toilet from overflowing its contents.