A Vertebrae Bend Restrictor (VBR) usually comprises a number of interlocking elements which articulate when subject to an external load and lock together to form a smooth curved "locking" radius. This radius is chosen to be equal to or greater than the minimum bend radius of the pipe that it is applied to. Once the elements have locked together the bending moment present is transferred into the elements and back through a specially designed steel interface structure into the adjacent rigid connection, therefore protecting the pipe / cable from potentially damaging loads.
Flexible pipes, flowlines, power cables and umbilicals are usually connected to a rigid structure such as a subsea riser base, PLEM or wellhead. To prevent these pipes from overbending at the interface between flexible and rigid structures, Vertebrae Bending Restrictors are often installed on the pipe. The VBR is specifically used where static or quasi-static loads act on a pipe, rather than dynamic loads when a Bending Stiffener would be more suited.
We are able to offer either a bespoke design or make use of a vast array of existing designs of bending restrictor elements to suit a wide range of pipes, umbilicals and cables. We are also able to design and manufacture the steel interface structure required.