Cryogenic seal for vacuum-insulated pipe

摘要

A cryogenic seal for vacuum-insulated pipe systems where the pipe system includes an inner pipe (16) connected to an outer pipe (14) by a bellows (24). The seal prevents cryogenic liquid from leaking from the inner pipe (16) into the annular vacuum space between the inner (16) and outer pipes (14) in the event of bellows (24) failure. One end of the bellows (24) is connected to the inner pipe (16) by a movable bellows ring (20) and the other end of the bellows (24) is attached to the outer pipe (14) by a fixed bellows ring (26). A bellows guide (22) is attached to the fixed bellows ring (26) and receives the movable bellows ring (20) in a sliding fashion. The seal may be positioned between the movable bellows ring and the bellows guide or between the fixed bellows ring and the outer surface of the inner pipe. The seal may also be positioned between the bellows shield and the movable bellows ring. The seal may be a leak control ring or the packed gland type.