DOUBLE-SHOULDERED THREADED JOINT OF DRILL PIPES Russian patent published in 2017 - IPC E21B17/42 F16L15/00 

FIELD: machine engineering.

SUBSTANCE: double-shouldered threaded joint of the drill pipes consists of a nipple and a coupling having inner and outer bearings joints. The gap in the thrust junction, in screwed but loose connection, is determined, depending on the threaded connection parameters and the correlation of the forces required to create a set of stresses in the dangerous nipple section and in the inner thrust junction, by the following relationship: δ=(1-Q_itj/Q_dns)Δl_n+Δl_c, where: Q_itj and Q_dns - the forces required to create a set of stresses respectively in the inner thrust junction and the dangerous nipple section; Δl_n and Δl_c - lengthening and shortening the threaded section of the nipple and the coupling, respectively, when tightening the connection.

EFFECT: ensuring strength and integrity of the double-shouldered threaded joint of the drill pipes.

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