Tips to choose the right nozzles and heads

It’s crucial to know thresholds for zone sizes to ensure proper head-to-head coverage. (Photo: Hunter Industries)

With water conservation top of mind, irrigation professionals seek to install the right combination of heads and nozzles on each site to position themselves as water management experts.

That goal requires them to gather site-specific information, according to Arianne Williams and Gracie Duarte, product managers at Rain Bird. Irrigation professionals need to consider a site’s design, soil type, terrain, water source, climates, size and shape of the area, compatibility of the components used on the same valve and the operational goals.

The irrigation components must have a performance range that fits within the available flow and pressure criteria, they add. On sites with high water pressure, pressure-regulating sprayheads can help avoid issues like misting and fogging. Technicians should pay attention to the varying needs in terms of hydraulics, local government restrictions and the customers’ wants as well, Williams says.

Factor in environment

Effective irrigation system designs must have head-to-head coverage and consistent distribution uniformity, says Michael Derewenko, Jain Irrigation solutions manager. Contractors need to consider the amount of site traffic and environmental variables like wind and sun coverage. There should be some overlap to prevent dry spots and account for wind.

Before installation, professionals should reference a spec chart to understand the operating pressures for different nozzles. For example, streaming rotor nozzles provide a slower, more consistent application of water to help cut through the wind, Derewenko says.

Technicians should space the sprinkler heads for the proper head-to-head coverage using a safety buffer based on site conditions like wind, says Kelsey Jacquard, category manager for mechanical irrigation products at Hunter Industries. 

“The distances provided by the manufacturer are in no-wind, perfect conditions,” she says.

Selecting the right sprinkler heads and nozzles will determine whether the irrigation system functions properly, manages water effectively and maintains a healthy landscape. In addition to knowing the available pressure and flow for the system, professionals must consider the landscape size to set the head spacing for good coverage, Jacquard says. The plant material on site also will determine the sprinkler pop-up height and water application.

Mistakes to avoid

Common mistakes irrigation professionals make when selecting nozzles and heads include oversizing the zone for the available pressure and spacing the heads too far apart, Jacquard says.

 “Knowing the available pressure and flow for a site provides the upper threshold for the size of the zone,” Jacquard says. “Include a safety buffer of at least 75 percent for available flow, and calculate the number of heads for the zone using the nozzle flow information from the manufacturer.”

After installation, contractors should run the system to ensure they’ve achieved head-to-head coverage — and ask customers to watch the system run once a week to note issues. Contractors also should monitor plant health.

“Dry or yellowing patches of grass in between heads or unusually green or soggy spots indicate that some areas are getting too little or too much water,” Duarte says. “Another telltale sign can be patches of mold, mildew, fungus or water pooling in caused by overirrigating.”

When contractors find a product they like, it can be tempting to use it for every project. 

“It may be a comfortable choice, but it might not be the best one for a particular application,” Duarte says.

Irrigation contractors should also pay attention to every site’s variations so they don’t max out the number of heads on a zone or space them too far apart. 

“The goal is to maintain a properly functioning irrigation system with effective water use, all while keeping the landscape healthy,” Jacquard says.