THREADED JOINT Russian patent published in 2020 - IPC F16L15/04 

FIELD: threaded connections.

SUBSTANCE: threaded connection (10) includes nipple (1) and coupling (2). Internal external thread (13) includes parallel section (131). Parallel section (131) is located at end section of internal external thread (13) adjacent to inner sealing surface (11) of nipple, and has thread recesses parallel to axis of pipe. Internal thread (23) of coupling (2) includes cone section (231). Height of thread in conical section (231) is greater than height of thread in parallel section (131). Da<Db is satisfied, where Da is the difference in diameter between adjacent thread tops (231a) in the cone section in nipple (1) longitudinal section and coupling (2), as determined, when connection is not screwed, and Db is difference between diameter of recesses (131a) of thread in parallel section (13) and maximum diameter of inner sealing surface (11) of nipple.

EFFECT: high sealing characteristic.

1 cl, 10 dwg