Performance characterisation of pressure regulation devices used in broad-acre irrigation

Large mobile irrigation machines are becoming a common sight in Australian broadacre irrigation, replacing traditional surface methods. These machines give the potential of irrigating large areas with high efficiency and with a uniformity of above 80% when designed correctly. A major component of the large mobile irrigation machine is the sprinkler application package commissioned with the machine. Pressure regulators are becoming a common part of the package when large mobile irrigation machines are commissioned. Pressure regulators are installed upstream of the nozzle and provide a constant output pressure regardless of the input pressure into the pressure regulator. The device acts as a variable headloss. Input pressure changes are a common occurrence on large mobile irrigation machines and typically are from topographic changes as the machines travel through the field. The application rate is directly influenced by the output pressure from the pressure regulator, thus this shows the importance of accurately understanding to performance of the pressure regulator. Reviewing previous literature it was known that the methodology development was a crucial part in understanding the pressure regulator performance. The development of a solid robust methodology was the primary objective of this dissertation. Eight stages of testing occurred each with incremental changes to develop the methodology for testing. The way the testing was undertaking proved to influence the results of the test. A statistical analysis in terms of an ANOVA and sample size calculations was undertaken on a limited set of data. It was found the for the 16 pressure regulators tested the means were not equal. 88 pressure regulators were found to be tested to understand manufacturing variation based on the normal model. The methodology by which the test was carried out was found to influence the outcome of the pressure regulator. Each result needs to be interpreted with reference to the methodology. Much more testing is needed to fully understand the pressure regulators performance and how they function on large mobile irrigation machines