Tubular threaded joint with male and femal threaded elements which screw together until two bearing shoulders interfere

摘要

The internal diameter (27) of the female shoulder (24) is smaller (IDB) than the diameter (IDP) of the internal peripheral surface of the male lip. The ratio R of these two diameters (IDB/IDP) is less than 1 but greater than or equal to 0.9 Tubular threaded joint with a male threaded element (11) in the end of one tubular component (10) and a female threaded element (21) in the end of a second tubular component (20). The male threaded element has a male thread (12) and ends with a male lip (18) with a male sealing surface (13) on the external periphery, an annular surface (16) for a male bearing (14) and an internal peripheral surface (17).The female threaded element has a corresponding female thread (22), a female sealing surface (23) on the internal periphery, and a female shoulder with an annular surface (26) for a female bearing (26). The male thread is screwed into the female thread until the two bearing surfaces meet. At this point the two sealing surfaces meet in an interference fit. The ratio R obeys the relationship (1.7 - 0.7S<2>)<0>.5 less than =R less than = (1.2 - 0.2%<2>)<0>.5, where S is the raio between the outer diameter (ODA) of the male bearing and the inner diameter (IDP) of the male lip. R is preferably equal to (1.3-0.3S<2>)<0>.5. The female shoulder has a minimum diameter (IDB) at a point D where the internal peripheral surface intercepts a conical surface of maximum shear (32) coaxial with the female threaded element, with a half-angle of 45 deg. at the point and the diameter reducing gradually.