Multi-start wedge thread for tubular connection
AssigneeHydril Company
InventorsBernard F. Beaulier, David L. Mallis
Life of this patent
Estimating the term…
Abstract
A threaded pipe connection includes a box member and a pin member. The box member has multiple internal, generally dovetail-shaped threads, each with stab flanks, load flanks, roots, and crests. The pin member also has multiple external, generally dovetail-shaped threads, each with stab flanks, load flanks, roots, and crests. The internal threads of the box member each increase in width in one direction, while the external threads of the pin member increase in width in the other direction so that the complementary flanks of the respective threads move into engagement upon make-up of the connection.
Claims35
A threaded pipe connection comprising:
- a box member having a plurality of internal, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, and crests, the internal wedge threads increasing in width in one direction and arranged to longitudinally overlap;
- and
- a pin member having a plurality of external, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, and crests, the external wedge threads increasing in width in the other direction and arranged to longitudinally overlap so that complementary flanks of the internal and external wedge threads move into engagement upon make-up of the connection,
- wherein a seal is formed upon make-up as the load and stab flanks of each external wedge thread on the pin member come into contact with mating load and stab flanks of the internal wedge thread of the box member, and
- one of the mating load and stab flanks is of the corresponding internal wedge thread and the other of the mating load and stab flanks is of an adjacent internal wedge thread on the box member.
A threaded pipe connection comprising:
- a box member having two tapered, internal, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, crests, and a thread start, the internal wedge threads increasing in width in one direction;
- a pin member having two tapered, external, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, crests, and a thread start, the external wedge threads increasing in width in the other direction so that the complementary flanks of the internal and external wedge threads move into engagement upon make-up of the connection;
- wherein
- the two thread starts of the box member and pin member are 180 degrees opposed;
- each individual wedge thread on the box member possesses a thread depth, taper, stab flank lead, and load flank lead that are identical to each corresponding wedge thread on the pin member;
- the roots and crests of the box member and the pin member have sufficient width to prevent any permanent deformation of the threads when the connection is made up;
- and
- contact between the roots and crests of at least one wedge thread on the box member and complementary roots and crests on the pin member occurs prior to contact between the stab and load flanks of at least one wedge thread on the box member and complementary stab and load flanks on the pin member.
A method of reducing stress during make-up of a threaded pipe connection, the method comprising:
- providing a box member having a plurality of internal, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, and crests, the internal wedge threads increasing in width in one direction and arranged to longitudinally overlap;
- providing a pin member having a plurality of external, generally dovetail-shaped wedge threads, each with stab flanks, load flanks, roots, and crests, the external wedge threads increasing in width in the other direction and arranged to longitudinally overlap so that the complementary flanks of the internal and external wedge threads move into engagement upon make-up of the connection and form a seal as the load and stab flanks of each external wedge thread on the pin member come into contact with mating load and stab flanks of the internal wedge thread of the box member, wherein one of the mating load and stab flanks is of the corresponding internal wedge thread and the other of the mating load and stab flanks is of an adjacent internal wedge thread on the box member;
- and
- rotationally engaging the pin member and the box member.
Dependencies are inferred from the claim text.