THREADED JOINT FOR PIPES Russian patent published in 2014 - IPC F16L15/04 

FIELD: machine building.

SUBSTANCE: outer periphery surface (30) of a nipple nose forms a convex curved line in an axial cross section of the nipple; the said convex curved line is a curved line N of a composed radius R consisting of several convex arches of different curvature radiuses (Rs) which are sequentially connected to the generating line of a cylindrical part near an element (5) with an external thread, and the curved line is curved so that the said curvature radiuses (Rs) of the arches are increasing as far as they are moving away from the element (5) with the external thread, and the tangents to the connection points of the arches coincide with the tangents to the respective arches being connected; and the inner surface of a clutch element (1) turned to the nipple nose (30) is presented as a wedge face (20) interacting with the outer periphery surface (30) of the nipple nose at coupling to the nipple element (3).

EFFECT: higher leakproofness, compression strength and resistance to friction corrosion.

11 cl, 3 dwg, 6 tbl