High strength, low torque threaded tubular connection
OwnerJohn D. Wattsinventor
Life of this patent
Estimating the term…
Abstract
A threaded pipe connection as shown in FIGS. 1, 4, 5, 6 or 7, having a thread form such as depicted in FIGS. 8-11, that has: improved sealing; increased resistance to mechanical loads; easy assembly and low makeup torque. Both pin (31) and box (45) may be cut on non-upset pipe ends and result in nearly 100 percent joint efficiency. Tension flank (33) and compression flank (34) may be formed on pin (31) at high flank angles measured from the tubular axis so as to withstand high axial loads without forcing the pin inwardly and the box outwardly, which would tend to separate the mating threads, break the seal and jump threads. Low torque is assured by the complementary forms of pin threads (32) and box threads (42) which confine the thread dope (49) to remain in the root gaps (52) and (54) during assembly.
Claims19
A threaded pipe connection for assembly with the use of pipe dope, the connection having box and pin members formed with mating pipe threads, the threads being formed with tension and compression flanks connected by crests and roots, the mating threads having an included angle between the flanks, comprising:
- the pipe dope being a desired mixture of grease and solid particles suitable to lubricate and seal between the mating threads;
- a thickness of first dimension below which, the solid particles will not compress between the mating threads;
- a thickness of second dimension above which, the solid particles will not seal between the mating threads;
- the mating threads being dimensioned and formed sufficiently complementary to each other such that at a position of full makeup of the connection, a compacted solid particle thickness of first dimension beyond which the particles will not compress is wedged between mating flanks simultaneously as a compacted solid particle thickness of third dimension intermediate in value to the first and the second dimensions, exists between the mating roots and crests, the third dimension being measured along a bisector of the included angle.
A threaded pipe connection having a box and pin formed with tapered mating threads for assembly with the use of pipe dope to lubricate and seal between the threads, the threads having a radial thread depth and an axial pitch length, the threads being formed with mating tension and compression flanks that are connected by crests and roots, the threads having an included angle measured in the gap between the flanks, comprising:
- the threads being dimensioned such that upon assembly of the connection, both tension and compression flanks are loaded against their mating flanks;
- the included angle being less than fifty-four degrees;
- the radial thread depth being more than fifty percent of the axial pitch length;
- the axial length of the crest being within the range of thirty-three to forty-six and one-half percent of the axial pitch length.
The connection of 1 or 3 further comprising:
- the mating threads being formed complementary to each other such that when they are placed in dry mating contact, no gaps wider than the first dimension will exist between the mating surfaces.
Dependencies are inferred from the claim text.