Patent ID: 6916048

Claim:
A device for fluidtight connection of a fitting to an internal combustion engine fuel injector, wherein said fitting comprises a high-pressure fuel supply conduit, and said injector comprises a hollow body having a threaded seat; said fitting having a threaded portion for engaging said threaded seat with the interposition of a sealing ring; and said fitting having another portion forming, with said threaded portion, a first annular shoulder which, in use, faces a second annular shoulder on said hollow body; characterized in that said shoulders are precision machined so as to be parallel in use; and in that said sealing ring is located between said shoulders so machined, further characterized in that said sealing ring is defined by a metal washer; wherein one of said shoulders has an annular groove for partly housing said washer, and the other of said shoulders is located on a flat, non-recessed surface and undergoes circular spot facing to obtain a series of circular cavities concentric with the axis of said threaded seat, wherein said circular cavities are characteristic of a surface roughness Ra=1.6.