AIR-TIGHT THREADED OILFIELD PIPE CONNECTION Russian patent published in 2007 - IPC E21B17/42 F16L15/00 

FIELD: oil and gas well construction, particularly threaded couplings or joints between rod and bit, or between rod and rod.

SUBSTANCE: connection comprises male and female pipes with tapered threads and support surfaces. The first support surfaces are in contact with each other and formed on outer spherical surface of male pipe end part and on inner conical surface of female pipe between tapered thread and pipe body correspondingly. The second contacting surfaces are created as conical end surface of male pipe and mating end conical surface of female pipe in transition area between the first conical surface to pipe body correspondingly, wherein conical end surface of male pipe has cone angle facing tapered thread of male pipe. Tapered threads define irregular trapezes in cross-sections and have 1:16 taper. Thread contour define negative angle along support edge and increased angle along inset edge. Male pipe has thread contour height less than that of female pipe.

EFFECT: increased connection reliability and air-tightness, as well as improved strength and assembling/disassembling ability.

1 dwg