Ongoing Improvements Keep Making I-25 Nozzles More Efficient than Ever

Hunter has taken a good thing and made it even better.

The Hunter I-25 nozzles have always had a reputation for excellent performance. After all, the rotor has been one of favorite products in its class for commercial, park and sports turf installations everywhere for a long time.

So, why improve?

“Well, first off, at Hunter, there has always been a philosophy of never resting on one’s laurels,” said Steve Hoveln, Hunter rotors product manager. “Even if a job is done well, there is always room for improvement and the chance to do that job even better.

“With the I-25’s nozzles, their performance has always been above the desired standards. But, just like a student can get ‘C’ or ‘B’ on a test and know it’s a passing grade, there’s always the desire to strive for the ‘A.’ Essentially, Hunter just wanted better grades.”

How Hunter Establishes Nozzle Ratings

In testing nozzles, objective data is gathered and then compared against an exact measurement. There are 5 different factors for objective data that Hunter compiles:

• Close-in watering–the amount of water that is dispersed through the nozzle right close to the sprinkler head. This is an important test for contractors.
• Scheduling coefficient–a number that relates to uniformity of coverage and the length of time it will take (run time) to adequately irrigate the entire turf area
• Wettest-to-driest–how wet the wettest area of coverage is compared against how dry the driest area is; a close ratio is most desired, indicating that the nozzle applies water uniformly
• Radius–makes certain that the nozzle performs to the ASAE testing standard for sprinkler radius. (this standard is referenced below all Hunter performance data charts)
• Flow–measured in GPM, this is the discharge rate of the nozzle. It also must match the published specifications.

Each of these different factors is given a particular weighting and the 5 scores are added together to give an overall nozzle rating.

Another area that is measured is the width of stream. As the water travels from the nozzle over the extent of its throw, there is a desired width for the stream at various points along that throw. Too narrow and the stream is too tightly packed to provide coverage in the close-in and mid-range areas. Too wide and the stream will waste water on non-turf areas, such as adjoining hardscapes (e.g., the running track that encircles a high school football field).

The goals for improving the performance of the I-25’s nozzles were to increase the overall score and to narrow the stream, with neither coming at the expense of the other.

All Nozzles Improved, Not Just the Popular Ones

Hunter engineers have worked especially hard at improving the performance for all of the I-25 nozzles, not just the most popular ones that come standard with every purchase.

“It might be convenient to overlook those nozzles that don’t get used too often,” said Hoveln, “but that wouldn’t be right. We want to give the same amount of attention to detail to every product that we produce.”

To measure performance, Hunter carries out its own independent tests under standardized optimal conditions–in a test facility according to ASAE standards under consistent water pressure.

Obviously, conditions in the field will vary from site to site and season to season, but Hunter test engineers use a regulated basis for comparing how the nozzles have improved.

Further, Hunter routinely sends sprinklers for testing at the Center for Irrigation Technology (CIT) in Fresno, California. This independent, un-biased testing center provides information on the performance of Hunter sprinklers to designers and contractors around the world.

“We’re proud of how much better our I-25 nozzles are now,” said Hoveln. “But not so proud that we’re done working on them. We’ll always be testing and engineering to make them even better. You can count on that.”