Swivel assembly

Abstract

A multi-product swivel assembly for carrying oil or other cargo and transmitting electrical power and signal currents, between a ship and stationary oil wells or other installations. The swivel assembly includes a non-rotating or stationary unit, a large upper unit that rotates about the stationary unit, and a center unit that rotates with the upper unit and which extends down within the stationary unit. The center unit includes a large vertical cylinder which surrounds a group of vertical pipes carrying inflammable fluids, and a vertical pipe filled with inert gas and surrounding a conduit that carries an electrical cable. In order to repair the upper rotating unit, as to replace one of the muliple seals thereon, bolts can be loosened to separate it from the center rotating unit. When the bolts are loosened, a shoulder on the stationary unit prevents the center unit from dropping, so that during later reassembly, the bolts will lift up the center unit to its rotating position. To permit access to the bottom of the center rotating unit, jacking bolts are turned to allow the lower portion of the stationary unit to drop down until the seals and the like on the center unit are exposed, the stationary unit being lifted back into place by turning the jacking bolts.