Swivel Stack Systems | OneSubsea

Swivel Stack Systems

Light, compact, high-pressure systems

The heart of the turret, mooring, and fluid transfer system

Reliability, safety, and flexibility are of key importance in securing maximum uptime for the FSO or FPSO facility.

Swivels ensure that all fluids (liquids and gas), controls, and power are transferred safely from the geostationary components (wells, flowlines, manifolds, and risers) to the rotating vessel and its processing plant under all environmental conditions.


  • Compact and light design requiring minimum space and structural support
  • Compatibility with any turret and any FPSO
  • High pressure capability up to 7,500 psi [520 bar]
  • Large throughput capacity
  • Enhanced safety and reliability, with continuous monitoring of the swivel stack system condition
  • Green-light philosophy confirming system availability before startup and during all phases of the operation
  • Independence from process fluid and operating pressures
  • Optimal seal operating conditions independent of pressure and temperature
  • Standardized sealing and bearing system to facilitate availability of spares
  • Double sealing between individual swivels and four dynamic seals between the process and the environment
  • No internal piping or flanges through use of channels in solid core
  • Capability of being installed in a single lift onto the FPSO
Diagram of a swivel stack