Abstract: A dish washing machine including a housing having an interior wash space and a liquid inlet. A spray nozzle sprays the liquid onto dishes. The machine further includes a heating tank for heating the liquid which is supplied to the rotating spray nozzle. A heat exchange system transfers heat from the liquid heated by the heating tank to the liquid added from the liquid inlet. The heat exchange system comprising a pipe system defining a first path therethrough and a second path therethrough, with the first heat exchange system transferring heat from liquid in the second path to liquid in the first path. A first surface portion of the pipe system of the first path engaging the liquid in the first path having a greater thermal conductivity than a second surface portion of the pipe system of the second path engaging the liquid in the second path.

Abstract: A dish washing machine comprising a fresh water reservoir for receiving fresh water configured to be heated, a first tank for receiving the initially heated fresh water from the fresh water reservoir and including a first heating system for heating the initially heated fresh water to form further heated fresh water, a second tank configured to receive the further heated fresh water and including a second heating system for heating the further heated fresh water to form further heated wash water, and a drain pipe for delivering the further heated wash water from the second tank through the fresh water reservoir and to a liquid outlet, with the drain pipe transferring heat from the further heated wash water to the fresh water in the fresh water reservoir to form the initially heated fresh water. The heating systems can comprise a positive temperature coefficient heating element.

Abstract: A double containment fitting for engagement with double containment pipes and comprising a one-piece integral structure having at least one outer cylinder having at least two outer receiving openings, at least one inner cylinder having at least two inner receiving openings, and a plurality of ribs integral with and spacing the at least one outer cylinder from the at least one inner cylinder, thereby forming an inner fitting flow area within the inner cylinder and forming an outer fitting flow area between the at least one outer cylinder and the at least one inner cylinder and between adjacent ribs. Each inner tube of the double containment pipes are connected to the double containment fitting by being located within one of the inner receiving openings. Each outer tube of the double containment pipes are connected to the double containment fitting by being located within one of the outer receiving openings.

Abstract: A double containment fitting for engagement with double containment pipes and comprising a one-piece integral structure having at least one outer cylinder having at least two outer receiving openings, at least one inner cylinder having at least two inner receiving openings, and a plurality of ribs integral with and spacing the at least one outer cylinder from the at least one inner cylinder, thereby forming an inner fitting flow area within the inner cylinder and forming an outer fitting flow area between the at least one outer cylinder and the at least one inner cylinder and between adjacent ribs. Each inner tube of the double containment pipes are connected to the double containment fitting by being located within one of the inner receiving openings. Each outer tube of the double containment pipes are connected to the double containment fitting by being located within one of the outer receiving openings.

Abstract: A method of washing dishes comprising providing a housing having an interior wash space with dishes positioned therein; spraying a wash liquid onto the dishes positioned within the interior wash space with at least one spray nozzle; spraying a rinse liquid onto the dishes positioned within the interior wash space with at least one spray nozzle after spraying the wash liquid onto the dishes; and emitting ultraviolet (UV) light onto the dishes during the step of spraying the wash liquid onto the dishes, during the step of spraying the rinse liquid onto the dishes, or during both steps of spraying the wash liquid onto the dishes and spraying the rinse liquid onto the dishes.

Abstract: A dish washing machine including a housing having an interior wash space and a liquid inlet. A spray nozzle sprays the liquid onto dishes. The machine further includes a heating tank for heating the liquid which is supplied to the rotating spray nozzle. A heat exchange system transfers heat from the liquid heated by the heating tank to the liquid added from the liquid inlet. The heat exchange system comprising a pipe system defining a first path therethrough and a second path therethrough, with the first heat exchange system transferring heat from liquid in the second path to liquid in the first path. A first surface portion of the pipe system of the first path engaging the liquid in the first path having a greater thermal conductivity than a second surface portion of the pipe system of the second path engaging the liquid in the second path.