The pressure loss in corrugated hoses is 100% higher than in new welded steel pipes. This means that in the case of corrugated hose as increase in diameter of 15% is required to reduce the pressure loss to value of the pressure loss in steel pipes.
Because of the nature of the bore of a corrugated hose, the pressure drops due to greater friction than that of a smooth size of corrugated hose related to a flow rate where water is a fluid. To use the chart, Read off on the vase line the flow rate required. Where a vertical line from the selected point on the baseline intersects the nominal bore line the pressure drop Is shown on the vertical axis, corresponding to the point of intersection.