The design of an irrigation system can be performed with the use of abacuses, graphs and tables, prepared directly by the firms producing material for irrigation, and which show, for the type of product which is considered (conducted and dispensers), the maximum allowable planimetric development under certain conditions of pressure, flow and slope. For example, for a laterals these catalogs show the maximum allowable development in length when using a certain diameter of the pipe and a certain emitter.

 

 

They did not cover the different slopes (which are assumed horizontal or sub-horizontal), nor the interaction with the other parts that compose the irrigation system (which may have 5 as 200 lateralss). Furthermore, the results reported are valid only for a well-determined supply pressure. These assumptions entail negative consequences, both on the uniformity of distribution of the flow rates provided and on the efficiency of the irrigation system itself, produced by a functioning, during operation, of the irrigation system different from that expected in the design stage. Of course, you can take advantage of these sizing tools, only with reference to irrigation equipment manufactured by the same company. It then determines a situation of uncertainty for the professional who, in the design of an irrigation system, in making a comparison of the solutions proposed by different companies can not disentangle among various methods of sizing.