PRESSURE TIGHT PIPE JOINT WITH ONE OR MORE INCLINED BEARING SURFACES EXECUTED BY MEANS OF PLASTIC EXPANDING Russian patent published in 2008 - IPC F16L15/04 

FIELD: transportation.

SUBSTANCE: pressure tight pipe joint has the first male tubular member provided with male thread, the first circular edge having first axial bearing surface, the first inner surface and section of the first outer surface. Also there is the second bearing surface and the second tubular member. The latter contains female thread similar to male thread, the second circular edge having third bearing surface, the second outer surface located opposite to the mentioned first inner surface and the second inner surface and the fourth axial bearing surface providing possibility to rest on the first bearing surface and determining among other things together with the second outer surface the circular bed corresponding to the mentioned first edge. The second and the third baring surfaces in initial condition represent conical surfaces having essentially identical inclinations allowing to provide during screwing the rest of the second bearing surface on the third bearing surface creating the first compressive radial and pressure-tight contact between the first inner surface or outer surface and the second outer surface or the third inner surface, and then in the process of diametrical expansion in the area of plastic yield with the help of expansion tool with axial movement to make the first outer surface and the third inner surface to determine locally the second compressive pressure-tight contact.

EFFECT: joint reliability enhancement.

41 cl, 12 dwg