Selecting the correct nozzle is one of the most crucial, yet overlooked, elements in irrigation system design.
Choosing the correct nozzle, whether it's for a spray head or a rotor, is easy if you take the time to study the nozzle charts in a manufacturer's product catalogue and select one that best suits your needs; irrigation equipment manufacturers have put a tremendous amount of effort into developing nozzles to fit almost every application:
For slopes and compacted soils, select a nozzle with a lower precipitation rate.
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.
For flexibility with spray heads, select a nozzle with an adjustable or variable arc.
Because nozzles are designed to work within a wide range of pressures, it is important to ensure 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 you may experience uneven coverage, and cause wet and dry spots. To correct this, several manufacturers offer devices that can be installed at the nozzle or are integrated in the sprinkler, such as the Rain Bird PRS Series.
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.