Tubular connection with cylindrical and tapered stepped threads
AssigneeHydril Company
InventorL. Steven Landriault
Life of this patent
Estimating the term…
Abstract
A tubular joint or connector of box and pin members is disclosed having first threads provided on a taper with respect to the axis of the joint and second threads which are cylindrical and axially separated from the first threads. The first and second threads are radially separated by a step region. Two metal-to-metal seals of complementary engaging sealing surfaces are provided, one adjacent the end of the pin member, the other axially disposed between the two threads. Reverse angle torque shoulders at the end of the pin member and the interior termination of the box member and hooked threads further characterize the joint and box and pin members.
Claims12
A tubular connection of pin and box members defining an axis comprising,
- first and second pairs of interengaged threads on the respective members, the first pair of threads being axially spaced from the second pair of threads, the first pair of threads provided on a taper angle with respect to the axis, the second pair of threads being cylindrical threads, the first pair of threads being radially stepped with respect to the second pair of threads,
- a first pair of engaged sealing surfaces on the pin and box members disposed adjacent the end of the pin member,
- a second pair of engaged sealing surfaces on the pin and box members disposed axially between the first and second pairs of threads, said second pair of sealing surfaces provided at a steeper angle than the taper angle of the first pair of the threads,
- engaged reverse angle torque shoulders, the torque shoulder on the pin member disposed on the end of the pin member, the torque shoulder on the box member disposed on the interior end of the box member, and
- wherein said threads are hooked threads having negative angle load flanks.
A pin member for a tubular member and adapted for coaxial connection to a box member, the pin member comprising,
- first and second axially spaced threads, the first threads provided at a taper angle with respect to the axis of the pin, the second threads being cylindrical threads, the first thread being radially stepped with respect to the second thread,
- a first frustro-conical sealing surface on the pin member disposed adjacent the end of the pin member,
- a second frustro-conical sealing surface on the pin member disposed axially between the first and second threads, said sealing surface provided at a steeper angle than the taper angle of the first threads,
- a reverse angle torque shoulder disposed on the end of the pin member, and
- wherein the first and second threads are hooked threads having negative angle load flanks.
A box member adapted for coaxial connection to a pin member disposed on the end of a tubular member, the box member comprising,
- first and second axially spaced threads, the first threads provided on a taper angle with respect to the axis of the box, the second threads being cylindrical threads, the first threads being radially stepped with respect to the second threads,
- a first frustro-conical sealing surface disposed adjacent the interior end of the box member,
- a second frustro-conical sealing surface about the interior of a box member disposed axially between the first and second threads, said second sealing surface provided at a steeper angle than the taper angle of the first threads,
- a reverse angle torque shoulder disposed on the interior end of the box member, and
- wherein the first and second threads are hooked threads having negative angle load flanks.
Dependencies are inferred from the claim text.