THREADED CONNECTION FOR CONNECTION OF STEEL PIPES Russian patent published in 2013 - IPC F16L15/04 

FIELD: machine building.

SUBSTANCE: devices for improvement of resistance of a threaded connection for connection of steel pipes is described, which (threaded connection) meets the requirements of AINP standards referring to a circular threaded connection. Threaded connection includes a male section with external thread of a triangular section and a coupling with internal thread of triangular section, which can be adjoined through the threaded connection to external thread that includes an unthreaded section located on the coupling end. The unthreaded section is shortened or located at some distance so that length of the unthreaded section in the coupling axial direction is maximum 1/2 (including 0) of the value specified in the above standards. The coupling shape specified in the above mentioned standards can be modified by providing a part with a recess on the coupling end and/or by creating an angle of skew on the end of internal thread, which comprises ±15° of inclination angle of lateral side of the internal thread turn.

EFFECT: invention improves reliability of threaded connection of steel pipes.

7 cl, 11 dwg