Elastomeric subsea flex joint and swivel for offshore risers

A flexible joint comprising, in combination:

• a first body having a first central passage and being adapted for coupling to a first conduit for conveying fluid between the first conduit and the first central passage;
• a second body having a second central passage and coupled to the first body for flow of fluid from the first central passage to the second central passage, the second body being adapted for coupling to a second fluid conduit for conveying fluid between the second central passage and the second conduit, the second body also being coupled to the first body for a limited range of movement of the second body with respect to the first body;
• a first bearing coupled to the first body and the second body for permitting flexing of the first body with respect to the second body to permit bending of axial direction of the first conduit with respect to the second conduit;
• an elastomeric flex element coupled to the first body and to the second body for resiliently resisting the flexing of the first body with respect to the second body and resisting swiveling of the first body with respect to the second body;
• and
• a rotational second bearing coupling the first body to the second body for permitting rotation to relieve torsional strain in the elastomeric flex element due to swiveling of the first body with respect to the second body;
• wherein at least one of the first body and the second body is adapted for the elastomeric flex element to resist flexing of the first body with respect to the second body starting from a mean position at which there is a substantial bend of axial direction of the first conduit with respect to the second conduit, the rotational second bearing sustains a loading force on the elastomeric flex element tending to resist rotation of the rotational second bearing due to static friction;
• and
• further comprising a loading mechanism for permitting the loading force on the elastomeric flex element to be reduced to facilitate adjustment of the direction of the substantial bend of axial direction of the first conduit with respect to the second conduit.

A conduit swivel joint comprising, in combination:

• a first body having a first central passage and being adapted for coupling to a first conduit for conveying fluid between the first conduit and the first central passage;
• a second body having a second central passage and coupled to the first body for flow of fluid from the first central passage to the second central passage, the second body being adapted for coupling to a second fluid conduit for conveying fluid between the second central passage and the second conduit, the second body also being coupled to the first body for a limited range of movement of the second body with respect to the first body;
• the second body including a tube having a flared end portion, the flared end portion having a first surface, the first body having a second surface engaging the first surface to form a first bearing for permitting flexing of the first body with respect to the second body to permit bending of axial direction of the first conduit with respect to the second conduit and for permitting swiveling of the first body with respect to the second body to permit a relative rotation of the first conduit with respect to the second conduit about an axis of the second conduit;
• and
• an elastomeric flex element coupled to the second body and to the first body for resiliently resisting the flexing of the first body with respect to the second body and resisting swiveling of the first body with respect to the second body, the elastomeric flex element having a first portion and a second portion, the first portion of the elastomeric flex element being secured to the flared end portion of the second body;
• and
• a rotational second bearing coupling the second portion of the elastomeric flex element to the first body for permitting the swiveling of the first body with respect to the second body.

A conduit swivel joint comprising, in combination:

• a first body having a first central passage and being adapted for coupling to a first conduit for conveying fluid between the first conduit and the first central passage;
• a second body having a second central passage and coupled to the first body for flow of fluid from the first central passage to the second central passage, the second body being adapted for coupling to a second fluid conduit for conveying fluid between the second central passage and the second conduit, the second body also being coupled to the first body for a limited range of movement of the second body with respect to the first body;
• a bearing coupled to the first body and the second body for permitting swiveling of the first body with respect to the second body to permit a relative rotation of the first conduit with respect to the second conduit about an axis of the second conduit;
• and
• an elastomeric clutch coupled between the first body and the second body for resiliently resisting swiveling up to a break-out torque at a limit of relative rotation of the first conduit with respect to the second conduit about the axis of the second conduit, and the elastomeric clutch permitting relatively unresisted swiveling for swiveling in excess of the limit of relative rotation of the first conduit with respect to the second conduit about the axis of the second conduit, the elastomeric clutch including at least one lobe engaging a region of elastomer.

A method of orienting and adjusting an assembly of a flexible joint coupled to a first conduit and a second conduit for passage of fluid between the first conduit and the second conduit, the joint including an elastomeric flex element for resisting bending of axial direction of the first conduit with respect to the second conduit from a mean position at which there is a substantial bend of axial direction of the first conduit with respect to the second conduit, a rotational bearing sustaining a loading force on the elastomeric flex element and permitting rotation to relieve torsional stress in the elastomeric flex element for adjusting a direction of the substantial bend of axial direction of the first conduit with respect to the second conduit, and a loading mechanism for reducing and increasing the loading force on the elastomeric flex element, the method comprising the steps of:

• a) when the loading mechanism applies a reduced loading force on the elastomeric flex element so that the rotational bearing permits rotation to relieve torsional stress in the elastomeric flex element, placing the assembly in a desired orientation having said mean position at which there is a substantial bend of axial direction of the first conduit with respect to the second conduit;
• and
• b) when the assembly has been placed in the desired orientation having said mean position at which there is a substantial bend of axial direction of the first conduit with respect to the second conduit, adjusting the ›adjustment! loading mechanism to increase the loading force on the elastomeric flex element, and thereby set the direction of the substantial bend of axial direction of the first conduit with respect to the second conduit.

A method of adjusting a flexible joint coupled to a first conduit and a second conduit for passage of fluid between the first conduit and the second conduit, the joint including an elastomeric flex element for resisting bending of axial direction of the first conduit with respect to the second conduit from a mean position at which there is a substantial bend of axial direction of the first conduit with respect to the second conduit, a rotational bearing sustaining a loading force on the elastomeric flex element and permitting rotation to relieve torsional stress in the elastomeric flex element for adjusting a direction of the substantial bend of axial direction of the first conduit with respect to the second conduit, and a loading mechanism for reducing and increasing the loading force on the elastomeric flex element, the method comprising the steps of:

• a) adjusting the loading mechanism to reduce the loading force on the elastomeric flex element so that the rotational bearing permits rotation to relieve torsional stress in the elastomeric flex element to facilitate adjustment of a direction of the substantial bend of axial direction of the first conduit with respect to the second conduit;
• (b) adjusting the direction of the substantial bend of axial direction of the first conduit with respect to the second conduit;
• and then
• (c) adjusting the loading mechanism to increase the loading force on the elastomeric flex element, and thereby set the direction of the substantial bend of axial direction of the first conduit with respect to the second conduit.

A conduit swivel joint comprising, in combination:

• a first body having a first central passage and being adapted for coupling to a first conduit for conveying fluid between the first conduit and the first central passage;
• a second body having a second central passage and coupled to the first body for flow of fluid from the first central passage to the second central passage, the second body being adapted for coupling to a second fluid conduit for conveying fluid between the second central passage and the second conduit, the second body also being coupled to the first body for a limited range of movement of the second body with respect to the first body;
• the first body having a semi-spherical bearing face, and the second body having a flared semi-spherical end portion contacting the semi-spherical bearing face to form a bearing coupled to the first body and the second body for permitting flexing of the first body with respect to the second body to permit bending of axial direction of the first conduit with respect to the second conduit and for permitting swiveling of the first body with respect to the second body to permit a relative rotation of the first conduit with respect to the second conduit about an axis of the second conduit;
• an annular elastomeric flex element disposed around the second body, the annular elastomeric flex element having a first end portion bonded to a surface of the flared semi-spherical end portion opposite to a surface of the flared semi-spherical end portion that is contacting the semi-spherical bearing face,
• an annular seat disposed around the second body, the annular seat being bonded to a second end portion of the annular elastomeric flex element;
• and
• an annular bearing cap disposed around the second body and secured to the first body, the annular seat and the annular elastomeric flex element and the flared semi-spherical end portion of the second body being disposed between the annular bearing cap and the semi-spherical bearing face of the first body, the annular bearing cap bearing against the annular seat for applying a loading force upon the annular elastomeric flex element to maintain the flared semi-spherical end portion of the second body in contact with the semi-spherical bearing face of the first body and for permitting relative rotation of the annular seat with respect to the annular bearing cap to permit swiveling of the first body with respect to the second body.