SEALED THREADED CONNECTION OF OIL-FIELD PIPELINES Russian patent published in 2010 - IPC F16L15/00 E21B17/42 

FIELD: machine building.

SUBSTANCE: sealed threaded connection of oil-field pipelines is formed with enveloped and enveloping pipes with buttress conic threads of 1:16 taper and profile angle from 12.5° to 13.5°. Profile of the buttress conic thread has a shape of a non-isosceles trapezium with a stop facet of a turn positioned at a big angle to load direction. Enveloped and enveloping pipes contact with their conic bearing surfaces correspondingly made on external and internal surfaces of pipes on the section between the conic thread and a pipe end and correspondingly between the conic thread and a pipe body in form of a conic bearing surface with taper 1:10 to the side of each pipe. Conic thrust surfaces are made correspondingly on the end of the enveloped pipe in form of conic thrust end surface with taper from 74.5° to 75.5° in the direction of the enveloped pipe and on internal surface of the enveloping pipe at the section of conic bearing surface transition to the pipe body in form of conic thrust surface of taper from 74.5° to 75.5° in the direction of the enveloping pipe. A cylinder boring parallel to axis of the said pipe is made on the enveloped pipe; while on the enveloping pipe there is made the cylinder boring parallel to axis of the said pipe. Cylinder borings create a cavity at assembly of the threaded connection; on one side the cavity is limited with the cylinder boring on the enveloped pipe, while on the other side it is limited with the cylinder boring on the enveloping pipe. Length of the cylinder borings are within specified intervals of dependence values.

EFFECT: raised pressure tightness of threaded connection of pipes and processability of its manufacture.

4 dwg