A fitting for joining pipes, tubes, or conduits improves
coupling capability particularly to a large bore
pipe, generally of 2 inches and larger in
diameter. The fitting includes a substantially cylindrical sleeve and ring. The sleeve has an inner surface defining a bore, configured to slidably receive the
pipe at an open end. The inner sleeve surface also includes protrusions, which deform the outer surface of the
pipe upon
swaging. The fitting also includes an outer surface having multiple stepped lands of ascending height relative to the open end. The ring has an inner surface configured to engage the multiple ascending steps on the inner sleeve surface. The inner surface of the ring has descending steps that are positioned to interfere with the multiple ascending steps on the outside of the sleeve. Axial motion of the ring causes the ring to slide over the sleeve and apply a radial
swaging force directly to the multiple stepped sleeve. The
swaging force makes the ring overcome the interference and push down on the multiple ascending steps of the sleeve, which swages the sleeve to the pipe. The multiple ascending steps of the sleeve are positioned relative to the descending steps of the ring, such that only one step at a time is swaged.