TUBE FITTING WITH INDICATING MEANS

摘要

An intrinsic gauging device for a ferrule type tube fitting (10) of the type having a coupling nut (14), a coupling body (12) and at least one ferrule (32), includes a precisely formed marking on the coupling body that is visually perceptible when the coupling is in a finger tight position, and that is covered or visually imperceptible or otherwise has a predetermined relationship with the coupling nut when the fitting has been initially pulled-up. In a preferred form, the marking is realized as a precision groove (50) or recess machined into a surface of the coupling body. The groove can be made more easily visually perceptible such as by roughening or knurling the surface, or coloring the surface, for example. Th e groove defines an edge (50b) at a precise position that corresponds to a predetermined axial displacement of the nut relative to the body for initial pull-up. The marking may also be formed with a precise dimension such as an axial length to provide a second edge th at corresponds to a predetermined axial displacement of the nut relative to the body beyond initial pull-up for fitting assemblies that are remade.