Head loss in the pipe

Have you been lucky enough to drill a well right next to your home? Wonderful! Now you can provide yourself and your house or summer cottage with clean water, which will not depend on the central water supply. And this means no seasonal shutdown of water and running with buckets and basins. You just need to install the pump and you're done! In this article, we will help you calculate the loss of water pressure in the pipeline, and already with these data you can safely buy a pump and finally enjoy your water from the well.

From school physics lessons, it is clear that water flowing through pipes, in any case, experiences resistance. The magnitude of this resistance depends on the flow rate, pipe diameter and the smoothness of its inner surface. The lower the flow rate and the larger the pipe diameter and smoothness, the less resistance. The smoothness of the pipe depends on the material from which it is made. Polymer pipes are smoother than steel pipes, and they also do not rust and, importantly, are cheaper than other materials, while not inferior in quality. Water will resist moving even in a completely horizontal pipe. However, the longer the pipe itself, the less significant the head loss will be. Well, let's get down to the calculation.

Unfortunately, pipes are completely straight only in a fairy tale. In real life, there are always various bends, dampers and valves, which cannot be ignored when calculating the water pressure loss in the pipeline. The table shows the values of the head losses in the most common local resistances: 90 degree elbow, round elbow and valve.

Each person who decides to independently equip the water supply of his home should be prepared for such a problem as reducing the pressure inside the system. As a rule, the reason lies in the fact that the total water pressure in the pipe falls: that is why the selection of the power of the borehole pump must be carried out with special care.

To accurately make the necessary calculations, it is most convenient to use special tables and formulas: they will allow you to get the most accurate parameters. It should also be taken into account that recently, supply water pipes are mainly assembled from polymer pipes. The pressure drop in a pipeline of this type is observed on a much smaller scale.

Along with linear losses inside pipelines, there may be so-called “local” resistances. First of all, we are talking about elements that provide branching and control of the flow rate - tees, taps, valves, elbows, valves, etc. The loss parameters within these products are influenced by the fluid flow rate and their configuration.