Abstract: A fluid flow profile regulating apparatus coaxial to a conduit carrying a fluid regulates fluid flow profile by smoothing out irregularities in fluid flow velocity transverse to the direction of flow. In one embodiment of the invention, the apparatus comprises a cylindrical chamber having a radius greater than that of the conduit and an internal set of ribs parallel to the longitudinal axis of the chamber. Each rib has a radial length less than the radius of the chamber to establish a cylindrical passage in the chamber having a radius less than that of the conduit open for uninterrupted fluid flow along the axis of the chamber. In another embodiment, although the radius of the chamber is not necessarily greater than that of the conduit, longitudinally displaced sets of internal ribs are angularly displaced with respect to each other. The longitudinally spaced, angularly offset ribs tend to cancel turbulence in the fluid developed between the ribs of the first set.