Comparing Sprinkler’s

Our rundown of sprinkler features will help you choose
the type that’s right for your application and budget.

By Jodie Carter, regional editor

A sprinkler head consists of three major components: the main body of the device, the nozzles through which water flows out of the body, and the swing joint at the bottom of the body which maintains the sprinkler’s connection to the lateral lines.

Sprinkler heads have been gradually downsized over the years, primarily for safety purposes. Some newer heads have a small surface diameter and include a protective thick rubber cover, which makes them a very safe alternative to the older-style sprinklers. Many new sprinkler heads use strong springs for positive retraction so the heads will not endanger the public by staying in the up position after watering is completed.

Today’s safer heads also have heavy-duty body caps that can stand up to the large equipment now being used in routine maintenance. Irrigation designers often choose a rotary sprinkler with a large nozzle selection, which allows users to fine-tune the flow of water out of the system. An experienced irrigation system designer will specify correct nozzle sizes to obtain “matched precipitation”–the rate (expressed in inches per hour) at which water is applied over the surface of the turf. “Matched precipitation” means the entire area is receiving a consistent amount of water.

Selecting Sprinkler Nozzles

Selecting the correct nozzle, whether it’s for a spray head or a rotor, is one of the most crucial, yet overlooked, elements in irrigation system design. Using the proper nozzle for your specific application will help you conserve water and, as a result, save money; it can also make the difference in the health and appearance of your turf grass.

Selecting a Nozzle for Your Application

For slopes and compacted soils, select a nozzle with a lower precipitation rate. For windy areas, select a nozzle with a low nozzle outlet trajectory.

To achieve even water distribution without having to separate part-circle from full-circle sprinklers, select a nozzle set that features a matched precipitation rate.

To ensure uniform watering using spray heads, select products that have an undercut nozzle?EUR??,,????'??+these have a second, undercut orifice for watering closer to the head.

For throw flexibility with spray heads, select a nozzle with an adjustable or variable arc.

The Right Nozzle for Your Water Pressure

Because nozzles are designed to work within a wide range of pressures, it’s important to ensure that you have the correct pressure at the base of the nozzle. Too much pressure, as is commonly the situation with spray heads, will result in misting. Misting creates a reduction in the radius of throw and which can cause uneven coverage, along with wet and dry spots. When choosing nozzles, water pressure will always affect the radius of water throw. Make sure you select a nozzle that will work with your water pressure and still achieve the correct throw for your existing system.

If you’re working primarily with rotors, keep in mind that too much pressure can cause the rotor to rotate too quickly. The nozzle stream of a fast moving rotor will “horsetail” and cause a severe reduction in the radius of coverage. Too little pressure will also result in a reduction in the radius of throw and uneven water distribution. Matched precipitation rate nozzles, for example, can eliminate the need for fixed arc patterns. This is a new innovation that allows landscape contractors to achieve more efficient water use and management.