SEALED THREADED CONNECTION OF CASINGS Russian patent published in 2015 - IPC E21B17/08 

FIELD: machine building.

SUBSTANCE: connection comprises male and female elements, on the ends of which thrust trapezoidal threads are made with an angle of taper 1:16. Angles of inclination of embedded and supporting edges of the thread profile to the normal line of the thread centreline 10-30° and 0-10°respectively. The external sealing unit is formed by radial sealing surfaces made at an angle 7-12° to the thread centreline and thrust terminal surfaces made at an angle 5-17° to the normal line of the thread centreline. The internal sealing unit is formed by radial sealing surfaces made at an angle 1.5-4.0° to the thread centreline. Along the length amounting 20-40% of the total length of the thread, made on the male element, starting from the thread beginning, the thread is cut with decrease of its height down to 50% of the total height of the thread profile. On the thread convergence of the male element the circumferential groove is made, the transition from the surface of which to the radial sealing surface is made spherical.

EFFECT: gas tightness of the connection at effect of randomly directed loads, improvement of characteristics of make-up capacity of the connection and improvement of its wear resistance.

4 cl, 4 dwg, 1 tbl, 1 ex