Siphon 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;
• and
• a trapway in flow communication with the toilet bowl,
• wherein, the flush valve assembly comprises
• a container having an open lower end and a closed upper end;
• a siphon flush valve positioned in the container upper end;
• and
• a conduit positioned in an interior of the container,
• wherein
• the container is in flow communication with the toilet tank,
• the conduit is coupled to the trapway and provides flow communication between the container and the trapway,
• the siphon flush valve comprises a tubular core, a head surrounding a top of the core, and a fluid spray initiator coupled to the head, the spray initiator configured to discharge water into the core to induce a siphon flow of surrounding tank water through the core,
• the trapway comprises a sump trap and a lower trap, and wherein the conduit is coupled to the trapway at a position between the sump trap and the lower trap, and
• when between flush cycles, 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.