Flush valve and toilet assembly

A toilet assembly, comprising

• a toilet tank to hold flush water;
• a flush valve assembly positioned in the toilet tank;
• a toilet bowl;
• a trapway in flow communication with the toilet bowl;
• a container positioned in the toilet tank, and
• a conduit extending from an interior of the container to the trapway,
• wherein
• the container is in flow communication with the toilet tank, the container having an open lower end and a closed upper end,
• the trapway comprises a sump trap, a first upstream weir, a lower trap, and a second downstream weir, and
• the conduit is coupled to the trapway at a position between the sump trap and the lower trap, and provides flow communication between the container and the trapway,
• the first upstream weir is positioned 2.0 inches or more vertically above a highest point of a trapway inlet,
• the sump trap contains a toilet bowl water seal between flush cycles,
• the first upstream weir is positioned at a vertically higher point than the toilet bowl water seal,
• the toilet assembly comprises an air volume defined by an upper end of the container, the conduit, and a portion of the trapway between the sump trap and the lower trap between flush cycles, and
• the air volume is under a positive pressure above atmospheric pressure.