A centrifugal separator for separation of at least two components of a fluid mixture which are of different densities, which centrifugal separator comprises a stationary frame, a rotatable part comprising a spindle and a centrifuge rotor, the rotatable part being supported by the frame to rotate around an axis of rotation, wherein the centrifuge rotor is mounted to a first end of the spindle to rotate together with the spindle and comprises a rotor casing enclosing a separation space, fluid connections for supplying or discharging process fluid or service fluid to or from said separator, the fluid connections comprising an inlet for supplying the fluid mixture to be separated to said separation space and at least one liquid outlet (39, 41) for discharging a separated liquid phase from said separation space; wherein the centrifugal separator comprises a seal assembly, arranged concentrically with the rotational axis at the inlet and/or at the at least one liquid outlet, for providing a seal between a first zone and a second zone, comprising - a rotatable sealing member attached to the rotatable part of the centrifugal separator comprising a first sealing ring and arranged to be fitted onto a rotating member that rotates around an axis of rotation, - a stationary sealing member attached to the stationary frame comprising a second sealing ring; wherein said second sealing ring is axially aligned with said first sealing ring around the axis of rotation; wherein said rotatable sealing member and said stationary sealing member thereby forming a connection between said rotatable part and said stationary frame, - means for bringing the first and second sealing rings into engagement with each other thereby forming at least one sealing interface between said first and second sealing rings; wherein said at least one formed sealing interface extends substantially in parallel with a radial plane (p) with respect to the axis of rotation; and further - wherein said first zone is located radially inside and extends axially through said sealing rings and said second zone is arranged radially outside said sealing rings; - wherein the first zone of the seal assembly is in fluid communication with a fluid connection of said separator and said second zone is in fluid communication with either a different fluid connection of said separator or a volume that is not in fluid communication with any process or service fluid of the separator, thereby forming a seal between said first and second zone; - wherein said first and second sealing rings are arranged so that a double contact seal having at least one chamber arranged at said radial plane (p) is formed upon engagement between the first and second sealing rings, and wherein the seal assembly further comprises at least one fluid connection to said chamber; and said at least one fluid connection is formed within said second sealing ring; - wherein said at least one fluid connection comprises a channel for supplying fluid to the chamber 11 and a further channel for withdrawing fluid from the chamber 11. - a rotatable sealing member attached to the rotatable part of the centrifugal separator comprising a first sealing ring and arranged to be fitted onto a rotating member that rotates around an axis of rotation, - a stationary sealing member attached to the stationary frame comprising a second sealing ring; wherein said second sealing ring is axially aligned with said first sealing ring around the axis of rotation; - means for bringing the first and second sealing rings into engagement with each other thereby forming at least one sealing interface between said first and second sealing rings; wherein said at least one formed sealing interface extends substantially in parallel with a radial plane (p) with respect to the axis of rotation; and further - wherein said first zone is located radially inside and extends axially through said sealing rings and said second zone is arranged radially outside said sealing rings; - wherein the first zone of the seal assembly is in fluid communication with a fluid connection of said separator and said second zone is in fluid communication with either a different fluid connection of said separator or a volume that is not in fluid communication with any process or service fluid of the separator, thereby forming a seal between said first and second zone; - wherein said first and second sealing rings are arranged so that a double contact seal having at least one chamber arranged at said radial plane (p) is formed upon engagement between the first and second sealing rings, and wherein the seal assembly further comprises at least one fluid connection to said chamber; and said at least one fluid connection is formed within said second sealing ring; - wherein said at least one fluid connection comprises a channel for supplying fluid to the chamber 11 and a further channel for withdrawing fluid from the chamber 11.