A tube fitting comprising: a core having at least one tubular end section, the tubular end section having an outer diameter, and a protuberance extending away from an outer surface of the end section; at least one tubular coupling sleeve having a distal end, the distal end of the tubular coupling sleeve having a first inner diameter that is approximately equal to or slightly larger than the outer diameter of the end section of the core, the coupling sleeve slidably fitted over the end section of the core, an inner surface of the coupling sleeve having a recess spaced from the distal end of the coupling sleeve, the protuberance located in the recess to limit sliding movement of the coupling sleeve relative to the core; and the fitting has a tee shaped configuration with three ends to which tubing can be coupled, wherein the tee shaped configuration includes a straight run having opposite ends to which tubing can be coupled and a lateral run extending perpendicularly from the straight run, the lateral run having a quick-connect coupling adapted to push couple with an inlet port or outlet port of a cooling plate, characterized in that, the tube fitting comprises at least one o-ring seal located within a corresponding annular groove in one of the outer surfaces of the end section and/or the inner surface of the coupling sleeve, in that the protuberance has a ramped and radially outwardly facing surface engaging a complementary ramped surface on a barb at an inner wall of the coupling sleeve, whereby the coupling sleeve is configured to be easily joined to the core and to prevent non-destructive decoupling, and in that the protuberance and the recess are provided with opposite stop surfaces that allow a predetermined range of motion. a core having at least one tubular end section, the tubular end section having an outer diameter, and a protuberance extending away from an outer surface of the end section; at least one tubular coupling sleeve having a distal end, the distal end of the tubular coupling sleeve having a first inner diameter that is approximately equal to or slightly larger than the outer diameter of the end section of the core, the coupling sleeve slidably fitted over the end section of the core, an inner surface of the coupling sleeve having a recess spaced from the distal end of the coupling sleeve, the protuberance located in the recess to limit sliding movement of the coupling sleeve relative to the core; and the fitting has a tee shaped configuration with three ends to which tubing can be coupled, wherein the tee shaped configuration includes a straight run having opposite ends to which tubing can be coupled and a lateral run extending perpendicularly from the straight run, the lateral run having a quick-connect coupling adapted to push couple with an inlet port or outlet port of a cooling plate, characterized in that, the tube fitting comprises at least one o-ring seal located within a corresponding annular groove in one of the outer surfaces of the end section and/or the inner surface of the coupling sleeve, in that the protuberance has a ramped and radially outwardly facing surface engaging a complementary ramped surface on a barb at an inner wall of the coupling sleeve, whereby the coupling sleeve is configured to be easily joined to the core and to prevent non-destructive decoupling, and in that the protuberance and the recess are provided with opposite stop surfaces that allow a predetermined range of motion.