U-bends with the reduced pressure losses to fluid distributing networks

A fluid network comprising at least one pipe connected to at least one U-bend, wherein the U-bend comprises an inlet, an outlet, and a bend, and the at least one U-bend has individually or in co-operative arrangement a flow passage having a continuously smooth and differentiable perimeter and centerline and a smoothly varying cross-section along the flow passage such that in the 5% of the flow passage from the inlet and the 5% of the flow passage from the outlet ARQ is from 1.0 to 1.02, and over the remaining 90% of the length of the flow passage not less than 5% of the flow passage has an ARQ from 1.02 to 1.15, and wherein the presence of one or more U-bends reduces the overall pressure drop within the fluid network by 10% or more when compared to the calculated pressure drop for a fluid network having a comparative flow passage with an ARQ along its length from 1.00 to 1.02, wherein ARQ is the ratio of aspect ratio (AR) to isoperimetric quotient (Q) of a section or segment of the flow passage perpendicular to the direction of flow (AR/Q).