Abstract: A timed pressure equalization member for use in a siphonic toilet to reduce water loss at the end of a flush cycle is disclosed. The equalization member functions to equalize the pressure in a pressurized chamber after a set period of time and consequently alleviates negative pressure within a pressurized trapway system at or near the end of a flushing cycle via a conduit, to help break the siphon at the end of the flush cycle, thereby reducing the amount of water drained from the water bowl/spot while the bowl is being refilled. At a resting state, the equalization member in the pressurized chamber is partially filled with water. The equalization member empties of water after a set period of time during a flush cycle and allows atmospheric air to enter the pressurized chamber (in fluid communication with the pressurized trapway) at or near the end of the flush cycle.

Abstract: A toilet that applies pressured air between an upper trap (30) that connects to the toilet bowl and a lower trap (32) that connects to a drain (16), includes a pressured air source (42) that holds a large volume of pressured air equal to at least 30% of the volume of the trapway passage (34) that connects the traps. The pressured air source includes a container (70) with its top coupled though a conduit (90) to the trapway passage, and with air in the container top compressed by water rising in the container after each flushing. The container top lies at least as high as the full water level (52) in the toilet tank when the toilet tank is full.

Abstract: A toilet has a source (42) that applies a vacuum to a trapway (14) at the beginning of a flushing to immediately flush the toilet bowl (12). As a result, water from the water tunnel 26 and the toilet bowl top channel 28 flow into the bowl after the flushing to create a large water spot (98) in the toilet bowl. A low water flush (e.g. 1½ liters to flush urine) can be obtained by not letting water flow out of a secondary volume (63) that lies outside a divider (140) in an isolator (40).