The rotating union jacket is mounted on the conduit, with the bearing formed by two sealed skeletons installed through upper and lower clips onto the shaft of the rotating union jacket. The rotating union jacket and the outer wall of the conduit have matching internal threads and external threads respectively. A locking nut is tightened at the upper end of the rotating union jacket onto the external thread of the conduit, securing the rotating union jacket in a specific position on the conduit. The skeleton seal is housed within the conduit. A layer of oil film provides lubrication and sealing. When air and liquid abrasive rise to the liquid surface, the air layer is compressed, hindering the upward climb of the liquid abrasive along the outer wall of the conduit.