THREADED JOINT FOR OILFIELD PRODUCTS PIPES Russian patent published in 2019 - IPC F16L15/04 

FIELD: pump building; oil and gas industry.

SUBSTANCE: invention relates to a threaded joint for tubular articles of an oil-field range, having excellent tightness. Threaded connection contains nipple with external annular peripheral surface formed on end side of steel pipe, and a section with an external thread made on the surface extending from the outer annular peripheral surface to the center of the steel pipe in the axial direction; and coupling with cavity, into which there is a nipple, in which there is a section with internal thread, engaged with a section with an external thread, and an internal annular peripheral surface, which enters into contact and rests against an external annular peripheral surface; in which nipple and coupling are connected to each other by means of threaded connection of section with external thread with section with internal thread so that external circular peripheral surface and inner annular peripheral surface come into contact with each other. Contact section between the outer annular peripheral surface and the inner annular peripheral surface forms a sealing portion, wherein the outer annular peripheral surface forming the sealing portion of the nipple is in form of a protruding arc, and the inner annular peripheral surface forming the coupling sealing section is made in the form of a recessed shape arc. Value of difference between radiuses of curvature of arc of external annular peripheral surface of nipple and arc of internal circular peripheral surface of coupling is selected in range of ±10 % and value of difference of distances in direction along pipe axis between location of center of arc of external annular peripheral surface of nipple and location of center of arc of internal circular peripheral surface of coupling is selected equal to 2 mm or less.

EFFECT: providing perfect tightness of threaded joint.

3 cl, 9 dwg