The world of sprinkler design won’t be mistaken for computer software development where new ideas come along every few years that change the way everyone does business.
As most irrigation manufacturers readily admit, a healthy number of their competitors offer products similar to those they produce. Because of such similarities in product offerings, manufacturers continually search for ways to improve their products’ performance, extend the life of their products or improve the way they service their customers.
It is in this light – servicing the needs of the customer – that many irrigation manufacturers are reexamining the products they offer in search of areas for improvement.
NOZZLE KNOWLEDGE. There may be no greater segment of the irrigation product market that has generated as much feedback as the nozzles through which irrigation is delivered.
As a result, just about every manufacturer of sprinkler products has added nozzle trees and variable arc nozzles to its lineup of late.
The key to a variable arc nozzle is its versatility in that it can be easily adjusted to spray an arc anywhere from 10 or 15 degrees to 360 degrees, whereas fixed spray nozzles can only spray one specific pattern, explained Karen Holloway, product manager for contractor sprayheads, Rain Bird Sales, Azusa, Calif.
“With fixed arc nozzles, contractors have to carry a lot of different nozzles around, especially for system maintenance,” Holloway added. “Variable arc nozzles let the contractor simplify that inventory to one 15-foot variable nozzle instead of a dozen 15-foot nozzles for different arc settings.”
“If a contractor needs to change a spray-head’s arc setting with a fixed nozzle, then a new nozzle needs to go in the sprayhead,” noted Jeff Carowitz, marketing manager, Hunter Industries, San Marcos, Calif. “With an adjustable nozzle, the same nozzle can be used for just about any arc setting.”
“Contractors want flexibility and convenience,” observed Dirk Lenie, residential/commercial marketing manager, Toro Irrigation, Riverside, Calif. “They want to reduce how many nozzles they stock, but as we see more odd shapes in the landscape contractors need more variety from the nozzles they use.”
Some manufacturers are offering the variable arc nozzles preinstalled on sprayheads.
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If someone said they were caught in a rainstorm that dropped 1 inch of water in an hour, you would have some idea of how “hard” or “heavily” the rain came down. A rainstorm that covers an area with 1 inch of water in one hour has a “precipitation rate” of 1 inch per hour or 25 mm/hr. Similarly, the precipitation rate is the “speed” at which a sprinkler or an irrigation system applies water. Are all precipitation rates the same? Absolutely not. Landscape irrigation systems and individual sprinklers themselves have widely varying precipitation rates. The rates typically vary from: Matched Precipitation Rates. A zone or system in which all of the heads have similar precipitation rates is said to have “matched precipitation rates.” Systems that have matched precipitation rates reduce wet and dry spots and excessive run times, which lead to high water consumption and increased costs. Knowing that sprinkler spacing, flow rates and arcs of coverage affect precipitation rates, a general rule of thumb is: as the spray arc doubles, so should the flow. 90 °Arc = 1 gpm (0.23 m3/hr; 3.8 1/m) 180 ° Arc = 2 gpm (0.45m3/hr; 7.6 1/min) 360 ° Arc = 4 gpm (0.91 m3/hr; 15.1 1/min) The flow rate of half-circle heads must be two times the flow rate of the quarter-circle heads. That way, the same amount of water is applied to each quarter circle area and precipitation is therefore matched. – Courtesy of Hunter Industries |
“Preinstallation saves the contractor time and money,” Holloway noted. “These have proven popular with projects like tract home developments that tend to be more price sensitive because they save nozzling time.”
Plus, contractors continue to be frustrated by the organizational headache of stocking so many different fixed arc nozzles for possible replacement needs.
“When contractors lose nozzles then they lose money,” observed Chip Kah, president, K-Rain, Riviera Beach, Fla. “Using variable arc nozzles lets them reduce the number of different products they have to stock, which is also a benefit for distributors.”
“High-end contractors still tend to use more plastic fixed arc nozzles or mill cut brass nozzles because they offer better performance and water saving characteristics,” added Gary Hilton, product manager, Weather-matic, Dallas, Texas. “Dealing with variable arc nozzles is really a double-edged sword in that way, but their performance has really been improving in the last few years.”
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“The trade off with adjustable nozzles is that they don’t water as well,” added Lenie. “They won’t have as good a distribution pattern and they can’t be as consistent across the breadth of the spray arc compared to fixed spray nozzles. Fixed sprays are simply designed to deliver better irrigation and there’s more precision molding in their manufacturing process.”
“Manufacturers are trying to improve the application rates so even if contractors don’t have matched precipitation rates with different adjustable nozzles, the rates are at least in the same ballpark,” agreed Laura Lopez, category manager for sprayheads, Irritrol Systems, Riverside, Calif., adding that changing the arc setting for some sprayheads may also change the flow rate, thereby creating the potential for over or underwatering.
One area in which manufacturers are trying to shift the irrigation paradigm somewhat is by increasing the applications of pop-up sprayheads in low-volume irrigation situations via microspray nozzles.
“New microspray nozzles let contractors combine the advantages of low-volume irrigation with the benefits of buried pop-up sprayheads so they don’t have to worry about tubing or other maintenance problems some low-volume systems can create,” noted Lenie. “The low-volume nozzles fit on standard, fully retracting pop-up sprayheads and are designed for use with landscape beds, ornamental and shrubs.”
“Some contractors tend to be leery of low-volume systems because of the tubing involved and the fact that a specifier’s plans call for a drip system, but that one system could include a number of plants with different irrigation requirements,” commented Lopez. “The low-volume nozzles can deliver water at rates as low as 10 gallons per hour in a 3- to 4-foot radius in a spray pattern with zero trajectory that will hit below the plant’s foliage.”
MIX AND MATCH. Despite manufacturers efforts to increase the versatility of pop-up sprayheads, the market continues to gradually move toward using more short- and mid-range rotors in place of the sprayheads.
“Using rotors allows a contractor to put more sprinklers on one line and cover greater area,” Carowitz noted. “Rotors are also more efficient because sprayheads apply water too quickly at times and waste water via runoff.”
While rotors will cost more than spray-heads on a per-unit basis, Carowitz explained that contractors need to examine the overall costs of the entire system with rotors replacing sprayheads.
“Since rotors have a greater coverage area than sprayheads, contractors can install fewer zones and less pipe, which translates into less labor and significant savings,” he pointed out.
Kah was in such agreement with Carowitz about the value of rotors that he predicted the shift from sprayheads to rotors will be one of the more significant trends in the market in the next five years.
“In addition to the water and cost savings rotors generate, I think we’re also seeing a trend in the housing market toward houses with smaller yards, which will translate into more low-cost irrigation systems,” Kah commented. “So part of this trend will be driven from a cost standpoint as contractors have to keep systems as simple and easy to install as possible.”
Increased nozzle selection has also been a trend for rotors.
“Obviously, arc variation doesn’t take place in the nozzle for rotors but in the rotor itself,” noted noted Christine Pappas, rotors product manager, Rain Bird, Azusa, Calif. “But we are seeing more rotors sold with nozzles pre-installed as a convenience factor.
“The number of nozzles available for rotors has also increased,” she continued. “Now, there can be as many as 12 or 16 nozzles available for a rotor, depending on the manufacturer. And this is important because we’re trying to serve a wide range of customers who are dealing with a variety of applications from low-angle applications to pressure compensating needs.”
Other manufacturers have noted the addition of greater pop-up heights for rotors – as high as 12 inches – for applications that place the sprinklers close to shrubs.
“Contractors should get away from having sprinklers on shrub risers because performance isn’t as good as with rotors designed for those applications,” related Lenie.
One other improvement for some rotors has been the addition of “memory arc” capabilities that enable the rotor to automatically return to its setting if a vandal twists it or it is bumped off course.
“This feature will save contractors callbacks where they would otherwise have to reset the rotor’s arc,” added Kah.
The author is Editor of Lawn & Landscape magazine.
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