Dishwasher with check valve in rotatable docking port

A dishwasher, comprising:

• a wash tub;
• a rack supported in the wash tub and movable between loading and washing positions, wherein the rack is adjustable between first and second elevations within the wash tub;
• a tubular spray element supported by the rack for movement with the rack, the tubular spray element having a connector for receiving wash fluid;
• a docking arrangement coupled to a rear wall of the wash tub and configured to engage with the connector of the tubular spray element when the rack is in the washing position to supply wash fluid to the tubular spray element, the docking arrangement including:
• a first rotatable docking port positioned to receive the connector of the tubular spray element when the rack is moved from the loading position to the washing position and the rack is adjusted to the first elevation, the first rotatable docking port being rotatable about a first axis of rotation and configured to engage the connector of the tubular spray element such that the tubular spray element rotates with rotation of the first rotatable docking port about the first axis of rotation when the connector of the tubular spray element is engaged by the first rotatable docking port;
• a second rotatable docking port positioned to receive the connector of the tubular spray element when the rack is moved from the loading position to the washing position and the rack is adjusted to the second elevation, the second rotatable docking port being rotatable about a second axis of rotation and configured to engage the connector of the tubular spray element such that the tubular spray element rotates with rotation of the second rotatable docking port about the second axis of rotation when the connector of the tubular spray element is engaged by the second rotatable docking port;
• a first check valve coupled to and rotatable with the first rotatable docking port, the first check valve movable between opened and closed positions and biased to the closed position when the connector of the tubular spray element is disengaged from the first rotatable docking port;
• and
• a second check valve coupled to and rotatable with the second rotatable docking port, the second check valve movable between opened and closed positions and biased to the closed position when the connector of the tubular spray element is disengaged from the second rotatable docking port;
• and
• a tubular spray element drive coupled to the first and second rotatable docking ports and configured to discretely direct the tubular spray element to each of a plurality of rotational positions about the longitudinal axis thereof when the tubular spray element is engaged by one of the first and second rotatable docking ports.