Check valves in dishwashing appliances

A dishwasher appliance defining a vertical direction, a lateral direction, and a transverse direction, the vertical, lateral, and transverse directions being mutually perpendicular, the dishwasher appliance comprising:

• a tub defining a wash chamber;
• a wash conduit disposed in the wash chamber on a rear wall of the tub;
• a first rack assembly slidably positioned within the wash chamber;
• a first spray assembly positioned in the wash chamber and configured to direct wash fluid at the first rack assembly;
• a second rack assembly slidably positioned in the wash chamber above the first rack assembly;
• a second spray assembly positioned in the wash chamber and configured to direct wash fluid at the second rack assembly;
• a third rack assembly slidably positioned in the wash chamber above the second rack assembly whereby the third rack assembly is slidable approximately along the transverse direction from a retracted position within the wash chamber to an extended position at least partially outside of the wash chamber;
• a third spray assembly positioned within the third rack assembly and configured to direct wash fluid at articles located in the third rack assembly, the third spray assembly comprising an inlet nozzle at one end;
• a conduit connector connected between the inlet nozzle of the third spray assembly and an outlet of the wash conduit when the third rack assembly is in the retracted position, whereby wash fluid is flowable from the outlet of the wash conduit to the inlet nozzle of the third spray assembly through the conduit connector;
• and
• a check valve within the conduit connector at the third rack assembly, the check valve defining an outlet positionable at the inlet nozzle of the third spray assembly.