Rotor Head Performance Charts
You can use these charts to get a baseline GPM (Gallons Per Minute) for each of your rotor style sprinkler heads. It’s also important to know when calculating PR (Precipitation Rate) many methods assume you have a matched precipitation rate. Spray head nozzles match themselves as long as they are all from the same manufacturer.
With rotor heads, you have to match them manually. So if you have a 6.0 gallon nozzle on a 360° head. In order to match your precipitation rate, you must put a 3.0 gallon nozzle anywhere you are only spraying 180°, and a 1.5 gallon nozzle spraying 90°. This is matched precipitation.
Rotor heads come with a nozzle tree, that has different size nozzles to install that allow you to match your precipitation rate. Some say LA for Low Angle.