"Value from technology and experience"

The fluid swivels have been developed mainly for the CALM buoy market but could be used when appropriate on FSOs. In order to cover as many piping configurations as possible, two main sizes of swivels have been envisaged:

• the 34" swivel, and,
• the 24" swivel.

Both swivels are designed for a fluid temperature range comprised between 0°C and 80°C and both swivels are low pressure swivels (up to 19.6 bar @ 38°C and 18.3 bar @ 80°C).

Some of the key criteria that were highlighted as important from the outset of the development and that were taken into consideration during this phase were:

• Life cycle costs.
• Ease of maintenance/inspection.
• Use of standard and proven equipment/parts whenever possible.
• Possibility to split the supply into two major trades 1) machining/assembly,

2) welding/construction.

The swivels feature:

• An ASME B16.5 #150 FF flange (34" or 24") interface with the piping components. This interface feature is important because it gives the possibility to split the supply into a mechanical part (requiring product knowledge and ad hoc testing equipment) and a welding/construction part with standard (ASME B16.5 or 16.9) components (typically a scope that the shipyard can handle). This split allows to drive down the CAPEX.
• Tensioning nuts (SUPERBOLT™ from Nord-Lock®) enabling the opening of the swivel without need for hydraulic tensioners or hydraulic torque wrenches.
• Seals (from TRELLEBORG) with a track record this type of applications.
• A sealing arrangement comprising three dynamic seals in series offering the possibility to include an OPS (Oil Pressurization System) between seal #1 and seal #2 whilst still maintaining a double barrier towards the environment.
• Good accessibility to inspect the seals' running surface.
• An orientation of the seal grooves allowing an easy installation of the seals and securing the seals in position until the swivel is closed.