home improvement

How Does A Toilet Work


History of the Toilet
The story of the toilet starts some 5,000 years ago. Some historians believe the first toilets came from Scotland, around 3000 B.C., where stone huts contained drains recessed into walls. Around 2800 B.C. in the ancient Mojeno-Daro civilization, toilets existed made of bricks with wooden seats. The ancient Greeks had a form of the toilet, found at the Palace of Knossos built in 1700 B.C., made from earthenware pans connected to terra-cotta pipes. The Roman bathhouses contained long bench-like toilets, but most often Romans threw their waste into the streets. It wasn’t until the late 16th century that the flush toilet started to become the modern luxury of today.

The Modern Flush Toilet
In 1596 A.D. Sir John Harrington of England published “Metamorphosis of Ajax” where he described a forerunner to the modern flush toilet. This water closet held a raised cistern with a small pipe and a release valve used to wash out the bowl. In 1775 Alexander Cummings developed the S-shaped pipe underneath the toilet basin. This pipe used the water level in the toilet to keep out foul orders from the sewer. By the end of the 18th century, and the onset of the Industrial Revolution, the flushable toilet went mainstream. Today the modern toilet consists of three main parts: bowl siphon, flush mechanism and the refill mechanism.

Bowl Siphon
The siphon tube leads out of the bottom of the toilet bowl, the S-shaped pipe. It curves upward to keep water in the bowl and curves downward so any excess water that enters the bowl flows away. It takes about two gallons of water to cause the toilet to flush. As the siphon fills, it sucks the water out of the bowl and down the sewer pipe creating the familiar flush sound, followed by a distinctive gurgling sound.

Flush Mechanism
The purpose of the flush mechanism, located in the tank, is to create a large force of water. This activates the siphon that creates the suction force to empty the bowl. The handle on the side of the tank is attached to a chain. When the handle is pushed the chain pulls up the flush valve that covers a two to three-inch diameter drain hole. The tank releases water into the bowl through holes around the rim and a larger hole, known as the siphon jet that pours straight into the siphon tube. The large amount of water entering the bowl creates the siphon effect and eliminates all water and waste in the bowl, in about 3 seconds.

Refill Mechanism
The refill mechanism, located in the tank, consists of a filler float, filler valve, and refill tube and over flow tube. Once the tank is emptied the flush valve resituates itself over the drain hole so the tank can refill. A filler floater floats on the water level of the tank and as the water drains out it lowers, triggering the filler valve. Once the valve is triggered, water fills the tank through two refill tubes. One refill tube fills the tank, the other fills the bowl through the over flow tube. The over flow tube runs up the center of the tank with a hole at its top. This prevents water form spilling out of the tank if the floater or filler valve fails, allowing excess water to drain out through the bowl instead of the top of the tank. Once the tank has reached capacity the filler floater rises and shuts off the filler valve.

Charlie Teschner started MESA Plumbing, Heating, and Cooling in 1982. Charlie has a journeyman and master plumber’s license. He was raised with a strong work ethic and he now applies those values to tasks such as Boulder heating repair.

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