THREADED PIPE CONNECTION Russian patent published in 2016 - IPC F16L15/00 

FIELD: pipes.

SUBSTANCE: invention relates to leakproof threaded joints comprises "metal-metal" sealing assembly. Threaded joint for steel pipes consists of pipe (nipple) and coupling elements, on which sections with outer and inner conical threads are arranged, wherein nipple ends with spout of axially symmetric shape, part of outer surface of which is sealing surface, which during assembly interacts with coupling mating sealing surface. Each of sealing surfaces consists of conic and toroidal sections, wherein toroidal section on nipple is located closer to threaded part, and on coupling is further from threaded part. In addition to it, nipple sealing surface, as well as part of adjacent to it non-contacting spout areas is located above of external thread recesses line. As a result, during connection assembly "metal-metal" sealing is formed, which consists of three sections, arranged so that contact pressure in central area on average exceeds triple pipe plasticity pressure, and on peripheral areas variation of contact pressure is described by Hertz function. Described pressure distribution provides required level of tightness at maintaining high antiscuff properties in pipes threaded connection "metal-metal" sealing zone.

EFFECT: invention improves reliability of pipes threaded connection under action of static and variable operating loads, including external pressure, compression, torsion and combined loads during pipe string bending and rotation.

14 cl, 17 dwg