Why You Should Check Your Sprinkler Package Every Three Years

Sprinkler packages are designed to optimize your water application efficiency and uniformity. Packages do degrade over time, however. The easiest way to check is with a small gallons per minute (GPM) meter, and a chart that shows what each head is supposed to emit.  

The first thing to degrade in the package (besides the hose) is the pressure regulator.  Pressure regulators are designed to provide a constant psi output no matter the input pressure.  They use a spring to accomplish this, and that spring can lose its “push” over time.  This often occurs near the inside spans, as they have a higher input pressure.

Why does this matter? A 20% change in the psi on the output side can result in a 10% change in the output GPM.  A 10% change in output could mean that a 1000 GPM sprinkler is trying to output 1100 GPM.  This could result in 100 GPM overwater in the first 5 spans and 100 GPM underwater in the last two spans.  This means you are overwatered on 40% of your field and under watering on 60% of your field. This can be seen during harvest, which is too late to do much about it.  I have also seen pivots where the last ten or so drops were outputting no water at all.

It is easy to change the regulators, and remember that nozzles can wear as well, especially with dirty water, so that they are larger than designed.  We can easily run a sprinkler chart on any brand of pivot and help get your efficiency and uniformity back to where it should be. For more information check out Senniger’s website at: https://agriculture.hunterirrigation.com/guide-irrigation-pressure-regulator#Issue