Fluid sealing assembly for a marine riser telescopic slip joint

Abstract

A fluid sealing apparatus for use on telescopic slip joints of marine risers. A sealed housing is secured to one of the two telescopic members of the slip joint in a concentric surrounding relationship to the other tubular members with an annular recess disposed adjacent thereto. Positioned within the annular recess is one or more resiliently deformable packing elements operably deformed by sliding movement of an associated fluid pressure responsive packing follower. The packing follower is movable within the recess toward a central guide bushing for urging the packing disposed therebetween to be radially inwardly deformed for initially establishing and maintaining the desired fluid leakage blocking seal. The packing follower forms an enclosed annular expansible chamber within the sealing housing in order that a preselected quantity of hydraulic fluid introduced within the enclosed chamber will move the packing follower sufficiently to establish the initial or reference urging on the packing for operably deforming the packing sufficiently to effect and maintain the initial seal. The packing follower is also exposed to the pressure contained within the marine riser for feeding additional packing radially inwardly as the working pressure of the contained fluid increases and the packing wears. To enhance the useful operating life of the resilient packing a central movement guide bushing is preferably disposed between the companion sealing elements.