THREADED JOINT FOR STEEL PIPES Russian patent published in 2021 - IPC F16L15/00 

FIELD: threaded joints.

SUBSTANCE: invention relates to a threaded joint for steel pipes. Threaded joint 1 comprises a tubular nipple 10 formed by one end section of a steel pipe and a tubular sleeve 20 adapted to be screwed onto the nipple 10 when the nipple 10 is inserted into the sleeve. The nipple 10 comprises an external thread 11 provided on the outer surface of the nipple 10 and having a wedge-shaped profile. The sleeve 20 comprises an internal thread 21 corresponding to an external thread 11 provided on the inner surface of the sleeve 20 and having a wedge-shaped profile. Threaded connection 1 satisfies the following expression: 3%≤(LP−SP)/LP≤8% (1), where LP means the pitch between the bearing sides 111 of the external thread 11, and SP means the pitch between the embedded sides 112 of the external thread 11.

EFFECT: invention is distinguished by both high tightening torque and high tensile strength.

4 cl, 8 dwg, 1 tbl