Hunter MP Rotator GPM, radius, and precipitation rate

A Hunter MP Rotator nozzle delivers water to a zone through multi-stream rotation instead of a single fixed fan. Two numbers matter when sizing the zone. Flow (gallons per minute, GPM, at design pressure) sets how much of the lateral's hydraulic budget each head consumes. Precipitation rate (inches per hour) sets the runtime needed to deliver a target depth of water. Hunter publishes both at 40 PSI dynamic at the nozzle, the design point for the entire family.

The defining feature of the MP Rotator line is matched precipitation: every nozzle in a family delivers the same depth of water per hour to its footprint, regardless of arc or radius setting. A 90° corner nozzle and a 360° island nozzle on the same zone both lay down water at the same rate per minute on the ground they cover. This is why MP Rotators are the standard answer for zones with mixed arcs and why head-to-head triangular spacing is straightforward to size — a single runtime works across the whole zone.

The standard MP Rotator families (MP1000, MP2000, MP3000) share a matched precipitation rate of roughly 0.4 in/hr. The short-radius MP800SR family delivers about 0.8 in/hr, twice the rate, because the smaller footprint means the same flow lands on less area. Never mix MP800SR and standard MP Rotators on the same zone; their precipitation rates will not match, and the zone will under-water the standard heads or over-water the MP800SR heads at any single runtime.

MP Rotator chart at 40 PSI

Source: Hunter Industries MP Rotator performance data, cross-referenced against the Nelson Irrigation MP Rotator Application Guide. Radius and flow are at full-radius (no radius-adjustment reduction). Precipitation rate is reported for both head-to-head square layout (HS = radius) and triangular layout (equilateral, HS = radius), calculated as 96.25 × GPM₃₆₀ ÷ (HS × RS) for square and 96.25 × GPM₃₆₀ ÷ (HS² × 0.866) for triangular. Triangular spacing has the higher rate because each head covers less area.

Hunter also publishes data at 25, 30, 35, 45, 50, and 55 PSI in the same chart. The MP Rotator operating range is 30–55 PSI; outside that range stream carry degrades. To run a family at its minimum radius (the bottom end of each radius range), regulate to 30 PSI with a PRS30 spray body; for everything else, 40 PSI on a PRS40 is the design pairing.

MP Corner footnote: Hunter does not publish per-arc precipitation cells for MP Corner because the wedge geometry breaks the standard head-to-head head-spacing × row-spacing calculation. The 0.40 / 0.45 in/hr values shown for MP Corner are the family-matched rate (the value at which an MP Corner nozzle waters in unison with adjacent MP1000 / MP2000 / MP3000 standards on the same zone), per Hunter's matched-precipitation guarantee. The radius and GPM cells are verbatim from Hunter's published MP Corner chart.

How to size a zone

Three numbers turn the chart above into a working zone design.

1. Add up the GPM. Sum the Flow column for every nozzle in the zone, picking the row that matches each head's arc. A residential zone with four MP2000-180° edges plus two MP2000-90° corners draws 4 × 0.74 + 2 × 0.40 = 3.76 GPM. Check that against the lateral and valve capacity (residential 1-inch service typically clears 8–10 GPM at the manifold; check the controller's per-zone budget too). If you're over, drop a nozzle family or reduce arcs.
2. Confirm the precipitation rate. Read the Precip column. For a standard MP zone (any mix of MP1000 / MP2000 / MP3000 nozzles) the answer is roughly 0.4 in/hr regardless of arc. For an MP800SR zone, roughly 0.8 in/hr. Use the square or triangular value depending on how your heads are laid out; triangular is preferred when geometry allows because the distribution-uniformity is higher.
3. Set the runtime. Target depth ÷ precipitation rate = minutes. For a 0.5-inch irrigation event on a standard MP zone: 0.5 ÷ 0.4 = 1.25 hours = 75 minutes. For the same depth on an MP800SR zone: 0.5 ÷ 0.8 = 0.625 hours ≈ 38 minutes. Split into multiple short cycles if you see runoff on slopes or compacted soil.

If the chart shows a row's GPM that pushes the zone over budget, the matched-precipitation property means you can drop one head's arc (and its GPM) without changing the runtime calculation; the remaining heads still water at the same rate. That's the lever standard fixed-spray zones don't have.

MP Rotator nozzles, by family

Representative female-thread SKUs from each family, all in stock at Total Sprinkler:

	Family / arc	Color	SKU
	MP-800SR-90 (90°–210°)	Gray + orange	HUN-58-1553
	MP-800SR-360	Gray + lime	HUN-58-1554
	MP-1000-90 (90°–210°)	Maroon	HUN-58-0015
	MP-1000-360	Olive	HUN-58-0014
	MP-2000-90 (90°–210°)	Black	HUN-58-0017
	MP-2000-360	Red	HUN-58-1203
	MP-3000-90 (90°–210°)	Blue	HUN-58-0020
	MP-3000-360	Gray	HUN-58-0019
	MP Corner (45°–105°, male thread)	Turquoise	HUN-58-1212

Male-thread (HT) variants and the 210°–270° models exist for each standard family; see the Rotary Nozzles category for the complete in-stock list.

Keep going

The MP Rotator's design pressure is 40 PSI dynamic at the nozzle, which is exactly what a pressure-regulated PRS40 spray body delivers. PRS30 bodies regulate to 30 PSI and are reserved for MP800SR zones running at their minimum radius. For arc and radius adjustment in the field, the Hunter MP Rotator Adjustment Tool (HUN-58-1077) is the standard key. For the rest of the Hunter line (Pro-Spray bodies, PGP and I-25 rotors, Pro-C and Hydrawise controllers) browse the Hunter brand category.