Rotor Head Precipitation Rate


Just curious, your default precipitation rate for Rotor Heads is 1"/hr. My system has Hunter PGP ADJ heads and Hunter specs them at around .35/hr for 180 arc and half of that for a 360 arc. Is your assumption of 1"/hr too high? Most rotor heads don’t put out nearly that much


Precipation rates specified on nozzle charts are theoretical values based on ideal geometric layout of the sprinkler heads in laboratory conditions. In the field conditions rarely mimic these experimental values. As soon as one changes the layout of the sprinklers, turns the nozzle reduction screw, or changes the arc, the precipitation rates change. I myself have seen Hunter PGPs put out 1"/hr in certain situations. I assume Rachio is attempting to be conservative in their defaults to avoid run-off. Only way you can really tell is to do a catch cup test or if you have a water meter measure precip rates from that. Then create your own nozzle in the zone settings. Good luck


Thanks. sounds like I need to put down some catch cups.