What curvature should the pipes have in an installation? - Fish Farm Feeder

The curves affect negatively the duration of the pipes, since in these the feed particles produce more abrasion when the radius of curvature is smaller. The recommendation is that the curves have the largest possible radius of curvature, never being less than 30D, with D being the outer diameter of the pipe. The use of elbows and curves at 90º is totally excluded