Patent ID: 7484773

Claim:
A self purging expansion joint for use with an externally pressurized fluid comprising: a bellows disposed about first and second conduits having adjacent ends moveable with respect to each other; a primary fluid flow passage through the first and second conduits; a first annular seal sleeve forming a peripheral seal between the first conduit and a first end of the bellows; a second annular seal sleeve forming a peripheral seal between the second conduit and a second end of the bellows; a flow-restricting orifice in the first annular seal sleeve; a purge fluid flow passage through the orifice, between the bellows and the first conduit, through a gap between the adjacent ends of the first and second conduits, and into the primary fluid flow passage; and a protective covering disposed about the bellows, wherein a proximal end of the protective covering is peripherally sealed to the first annular seal sleeve and an opening at a distal end of the protective covering allows the ingress of the externally pressurized fluid.