Sprinkler Zone Flow for a Target Precip Rate

gpm = PR x zone area / 96.3 -- how a designer picks nozzles to sum to the right flow. A 1.5 in/hr rate over 1,200 ft^2 needs about 18.7 gpm of heads. Answers 'how much flow for this rate' instead of the rate from a set flow. Keep sprays and rotors on separate valves; the supply and valve must pass the flow. A design estimate, not a system audit.

required_gpm = target_precip_in_hr x zone_ft2 / 96.3, the inverse of precip_in_hr = 96.3 x zone_gpm / zone_ft2 (the 96.3 constant = 231 in^3/gal / 144 in^2/ft^2 x 60 min/hr spreads 1 gpm over 1 ft^2).

First-principles precipitation-rate relation with the Irrigation Association design references and the Rain Bird / Hunter design manuals (by name), solved for the flow; no edition cycle.

The precipitation-rate relation and the 96.3 constant are public irrigation-design practice. The nozzle chart and the matched-precipitation rule are in the manufacturer's design manuals.

Estimate. AHJ and licensed professional govern.

Field names used by the API: target_precip_in_hr, zone_ft2, required_gpm

• Precipitation-rate relation required gpm = target PR (in/hr) x zone area (ft^2) / 96.3Irrigation Association / manufacturer design manuals
• Head flows the per-head flows are the manufacturer's nozzle-chart values at the operating pressureRain Bird / Hunter nozzle charts
• Matched precipitation sprays (~1.5-2 in/hr) and rotors (~0.4-0.8 in/hr) apply water at very different rates and must not share a valveIrrigation Association design references