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

A fluid network comprising at least two pipes 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, an 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 an overall pressure drop within the fluid network by 10% or more when compared to thea 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), wherein L is the length and D is the inner diameter of the at least two pipes and further wherein the ratio L/D of the at least two pipes connected to the at least one U-bend is greater than 0 and less than 20, wherein Rb is half the distance between the center of the at least two pipes being connected by the at least one U-bend, and further wherein the ratio Rb/D is greater than 1 and less than 4.