The Gravity Flush

Most modern toilets work using gravity, a siphon effect and a supply of water to move waste down the does a toilet work

  • When you push the flush lever or flush button, that action opens the flapper valve in the bottom of the tank.
  • The water in the tank is released very quickly into the bowl through a series of holes in the rim.
  • A combination of water, gravity and a siphon effect through the trapway is employed to move waste products from the bowl, through the trapway and on its way to the sewer or septic tank.
  • After all the water in the tank is gone, the flapper valve settles back down on its seat. The fill valve then starts slowly allowing water into the tank.
  • When the water reaches the proper level, the fill valve shuts off, making the toilet ready and waiting for the next flush! For safety there’s also an overflow tube in the tank lets excess water flow out of the tank and into the bowl if the fill valve fails to shut off. The overflow tube ensures that your bathroom won’t flood if the fill valve fails although your water usage might increase.

Pressure Assist Flush Toilets

As we’ve mentioned previously, there is a flush technology that uses ordinary household water pressure to help flush waste down the toilet, rather than pure gravity and a siphon effect.

  • The pressure assist flush toilets are similar to the conventional gravity-flush toilets in appearance, except for the fact that inside the toilet tank lies an internal tank that stores water, under pressure.
  • There is no flapper valve or fill valve. The pressure tank stores water under line pressure from your home’s own water supply at around 40 to 60 psi (pounds per square inch) of pressure.
  • When you operate the flush lever on a pressure assist flush toilet, the water under pressure in tank is released under pressure through holes in the rim, moving waste into the trapway and out of the toilet much faster that a gravity-fed toilet can.

This super-flush is a much more positive flush and the water under pressure can move more waste using the same amount of water, while also scouring the bowl with the pressurized water.