THREADED CONNECTION OF OIL WELL TUBING (VARIANTS) Russian patent published in 2008 - IPC F16L15/08 

FIELD: mechanic.

SUBSTANCE: the invention refers to tube tapered threaded connections. The coupling element of the threaded connection has a coating on its threaded portion applied by the method of the zinc impregnation. The technical result of increasing the length of the input cylindrical hollow chamfer of the threaded connection with internal thread to the size amount of the thread tightness produced by the zinc impregnation addition determined using the applied empirical formula, is the increase in reliability of the connection under operating conditions, because it excludes the possibility of over-tightening the connection with intention to achieve the nominal tightness, and also the damage of the outmost threads protruding from the coupling element during operation. Thanks to the increase of the hollow chamfer length, during forced rotation using the standard torque, the threaded part of the element with the male thread becomes almost hidden in the hollow chamfer and thus protected against mechanical influence of drillings fluid.

EFFECT: increased reliability of thread.

2 cl, 3 dwg