Rotor and Nozzle Selection Guide
The correct rotor is the model and nozzle combination that reaches the required spacing at the actual operating pressure while keeping flow within the zone's capacity. Manufacturer performance tables, not nominal product names, are the final reference.
Which rotor suits a particular radius?
| Design question | What to check |
|---|---|
| Required radius | Distance between heads and the manufacturer's tested radius at operating pressure |
| Arc | Full-circle or adjustable part-circle operation |
| Available pressure | Dynamic pressure at the operating head after all losses |
| Available flow | Combined nozzle flow for every head operating on the zone |
| Application | Residential, commercial, sports-field or golf duty |
| Site conditions | Water quality, filtration, wind, slope, reclaimed water and vandal resistance |
For even coverage, layouts commonly use head-to-head spacing: each sprinkler should reach the next sprinkler. Final spacing must account for wind, pressure variation and the selected manufacturer's data.
How pressure affects nozzle performance
Too little pressure can reduce radius and disturb distribution. Excessive pressure can increase misting, wind drift and flow. A pressure regulator or pressure-regulated body may be appropriate where pressure is higher than the nozzle's intended range.
How flow affects zone design
Add the published flow of every nozzle on the zone at the proposed operating pressure. The total must remain below the reliably available supply after allowing for simultaneous demand and hydraulic losses. A larger nozzle generally needs more flow; increasing pressure also changes flow.
Match precipitation rates
Heads operating together should apply water at compatible precipitation rates. Full-, half- and quarter-circle nozzles may need different flow rates to apply a similar depth over their respective areas. Do not mix sprays, rotary nozzles and large rotors on one zone unless their precipitation rates and operating requirements have been deliberately matched.
Example selection ranges
Manufacturer data illustrates why model-level checks matter. Rain Bird publishes landscape rotor ranges around 4.6–10.7 m for specified models and pressures, while Hunter I-25 configurations extend into approximately 12–22 m depending on nozzle and pressure. Sports-field and golf rotors can operate at materially greater radii and flows. These are examples, not substitutes for the exact performance table for the selected model.
Browse Rotors, Sprays and Nozzles.
Information TMI needs to check a selection
- Required radius and arc.
- Dynamic pressure at the proposed head.
- Available flow at that pressure.
- Number of heads on the zone.
- Pipe size and approximate run length.
- Elevation difference and water quality.
- Residential, commercial, agricultural, sports or golf application.
Manufacturer references
Use the current model-specific performance data from Hunter Industries and Rain Bird. For broader hydraulic design principles, see the Rain Bird Landscape Irrigation Design Manual.