Abstract: An elastomeric flex joint is provided with a rotational bearing so that torsional stress is relieved by slip of the rotational bearing. In a first embodiment, the flex joint is designed to resist flexing from a mean position at which there is a substantial bend of axial direction, and the rotational bearing does not normally slip. An adjustment mechanism reduces the loading on the elastomeric flex element and the rotational bearing so that the bearing will slip during an initial orientation or during an adjustment of the joint. In a second embodiment, all small torsional deflections are absorbed by the elastomeric flex element, and large torsional deflections are absorbed by the rotational bearing. This is desirable because the elastomeric flex element has a greater fatigue capacity for small oscillations than the rotational bearing. An elastomeric clutch can be used to precisely control the break-out torque.

Abstract: A compression element having a deflectable elastomeric member is disclosed. The compression element exhibits a decreasing axial spring rate in response to axial movement and compression of the deflectable member. The compression element may be used alone or in combination with other compression elements in riser tensioner systems to maintain a substantially constant upward tensioning force on a riser as it moves axially relative to a floating platform.

Abstract: A riser tensioner system for applying a substantially constant tensioning force to a riser and allowing a floating platform to move within a given range along a longitudinal axis of the riser. The system includes a plurality of tensioner assemblies each of which are coupled to the riser and to the platform. Each of the tensioner assemblies includes an upper member, a lower member, a connecting member coupled to the upper and lower members, and intermediate members coupled to the upper and lower members at a point intermediate the ends of the upper and lower members. At least one of the upper member, the lower member, and the intermediate members are adapted to provide a constant tensioning force. The arrangement of the upper member, lower member, connecting member, and intermediate members further provide a linkage whose centerline in angularly spaced from the longitudinal axis of the riser by a substantially constant amount throughout the range of motion of the linkage.

Abstract: A compression element having a deflectable elastomeric member is disclosed. The compression element exhibits a decreasing axial spring rate in response to axial movement and compression of the deflectable member. The compression element may be used alone or in combination with other compression elements in riser tensioner systems to maintain a substantially constant upward tensioning force on a riser as it moves axially relative to a floating platform.

Abstract: An improved conduit seal is provided for the upper connector assembly (10) of a TLP where the upper end of a tether (14) is pivotally secured within the tether conduit (38) of a floating platform (12). The conduit seal includes an annular elastomeric seal (48) and a series of mounting blocks (52) bonded thereto. The tether mounts a CLB housing (24) which has an annular lip (74) with a continuous groove (80). Each of the mounting blocks is provided with a locking pin (84) which can be hydraulically driven into the groove (80) to lock the mounting blocks on the CLB housing, and confine the seal (48) relative to the CLB housing.

Abstract: An improved keyhole latch is provided for securing offshore structures in place. The back flange of the flex joint and latch assembly has a male portion and the load ring of the receptacle has a female portion. By matching the male and female portions, rolling of the load ring and flex joint and latch assembly is minimized and the noncontinuous surface on the load ring is strengthened.