Rotating control device assembly for use with a subterranean well

(canceled)

A system for use with a subterranean well, the system comprising:

• a rotating control device assembly comprising an outer housing configured for connection in a riser string, and a rotating control device releasably secured in the outer housing,
• the rotating control device comprising at least one annular seal configured to seal about a tubular received in the rotating control device, and an inner mandrel rotatably mounted by a bearing assembly, and
• the bearing assembly comprising first and second thrust bearings on respective opposite sides of a radially enlarged bearing support formed on the inner mandrel, and first and second biasing devices biasing the respective first and second thrust bearings toward the bearing support, in which the rotating control device further comprises first and second rotary seals that seal radially between the inner mandrel and the bearing assembly, a flow passage configured to provide fluid communication between an annulus formed axially between the first and second rotary seals and a chamber external to the rotating control device, and a check valve that permits flow from the flow passage to the chamber but prevents flow from the chamber to the flow passage.

(canceled)