Non-integral flexible pipe risers
A non-integral (or bundled) flexible-pipe riser is an assembly of individual flexible pipes constrained together at one or more intermediate points along the riser’s length. These constraints can be a pipe tray, a common flotation device or spacer bars. Depending on the design of the common attachment points, individual lines may or may not be retrieved separately.
Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards