Prestressed spigot and socket joint rising main oil rig - uses screw jack effect with ring rotor coupling sleeve assembly and ring can be locked

摘要

The demountable prestressed spigot (2) and socket (1) joint may connect two pipes in a rising main of a maritime oil rig. It uses a coupling sleeve (15) with a lockable retaining ring (20) to obtain a stressed joint by screw-jacking. Sleeve (15) has two circumferential rows of bore teeth (1A,1B) which engage socket barrel counterparts (15A,15B) by means of a bayonette action, being immobilisable in either the engaged or the disengaged position. Ring (20) screws into place to clamp the joint, with talons (23,15A) engaging shoulders (24,1B). Stud (30) in alternative blind bores (29) may be used to effect ring (20) rotation by means of a tangential jack, and a radial screw (24) may be wound onto a cammed face (41) to lock the stressed assembly.