The web's mother lode of free irrigation information!
Irrigation Product Listings & Reviews
MP Rotator Stream Rotor Nozzle
Hunter's MP Rotator is a small stream rotor-type nozzle that fits onto a spray sprinkler body. This combines the low precipitation rate and greater radius of a rotor-type sprinkler with the small size and lower cost of a spray-type sprinkler. The sprinkler body is not included, the nozzle fits on any of Hunter's standard spray-type sprinkler bodies. In other words for this sprinkler you would need to buy a spray sprinkler pop-up body, and then you would install the MP Rotator nozzle onto the body in place of the standard nozzle. In addition to the Hunter bodies, the MP Rotator nozzle will fit on all brands of pop-up bodies that use universal threads. It is available in both female and male threaded nozzle versions.
The MP Rotator was formerly made by the Walla Walla Sprinkler Company. Hunter bought the rights to the product in 2007 and it is now distributed in the USA under the Hunter brand name.
The MP Rotator nozzle is turned by a turbine powered by the water flow through the nozzle. Unlike other rotors, it does not have a gear box to control the rotation speed. Instead, a thick fluid encased in the body is used to control the speed. The nozzle has held up well over time in my tests of it.
- Matched precipitation rate. You select the nozzle size based on the radius. Different radius nozzles may be mixed together on the same valve zone.
- Adjustable arc. The arc can be adjusted by turning a collar on the nozzle. The precipitation rate remains the same when the arc is changed.
- Adjustable radius. The radius can be reduced using a screw on top of the nozzle. As you reduce the radius the precipitation rate will stay reasonably uniform.
- Low water application rate. The precipitation rate is very low which reduces run-off potential and also allows the use of smaller pipe. However, the trade off for lower precipitation is that you must water for a longer time to give the plants enough water. Lower precipitation rates also increase the susceptibility to wind distortion of the sprinkler uniformity.
|MP1000 90-210||8'-15', 90-210 degree pattern, female nozzle.|
|MP1000T 90-210||8'-15', 90-210 degree pattern, male nozzle.|
|MP2000 90-210||16'-21' 90-210 degree pattern, female nozzle.|
|MP2000T 90-210||16'-21' 90-210 degree pattern, male nozzle.|
|MP2000 210-270||16'-21' 210-270 degree pattern, female nozzle.|
|MP2000T 210-270||16'-21' 210-270 degree pattern, male nozzle.|
|MP2000 360||16'-21' 360 degree pattern, female nozzle.|
|MP2000T 360||16'-21' 360 degree pattern, male nozzle.|
|MP3000 90-210||22'-30' 90-210 degree pattern, female nozzle.|
|MP3000T 90-210||22'-30' 90-210 degree pattern, male nozzle.|
|MP3000 210-270||22'-30' 210-270 degree pattern, female nozzle.|
|MP3000T 210-270||22'-30' 210-270 degree pattern, male nozzle.|
|MP3000 360||22'-30' 360 degree pattern, female nozzle.|
|MP3000T 360||22'-30' 360 degree pattern, male nozzle.|
- Minimum pressure: 30 PSI
- Maximum pressure: 50 PSI
- Universal Female or Male Threads on nozzle.
This model is a type of rotor known as a "stream rotor". A typical rotor type sprinkler has a single stream of water that moves back and forth. A stream rotor has multiple streams of water that rotate around the rotor, one following the other. The streams of water always rotate in the same direction. The result is an interesting appearance, often described as spider legs moving around in a circle. On part circle models a stream appears at one edge of the arc, and then begins to rotate toward the other end of the arc. After it has gone a short distance another stream starts. As each stream reaches the end of the arc it disappears.
Special considerations when using stream rotors:
Stream rotors are very sensitive to spacing issues. The main problem is that with a stream rotor the water is divided into multiple streams. This means each individual stream of water is smaller than it would be for a standard rotor. These smaller streams are much more sensitive to wind. So it is best to avoid using stream rotors in windy areas. Do not space stream rotors farther apart than the actual radius given by the manufacturer. This is a critical rule, stream rotors are not forgiving if you make a mistake in the design. So if the manufacturer says the stream rotor has a 25 foot radius, you should never space the rotors more than 25 feet apart.
Stream Rotors and Slopes:
Stream rotors are popular for use on steep slopes. This is because the small streams apply water more slowly to the ground than either spray heads or standard rotors. A slower application rate of the water allows more time for it to soak into the ground, which results in less water run-off and related soil erosion. However this advantage comes at a cost, as slopes and wind tend to go together. As noted above, stream rotors are very sensitive to wind. So it is best to space stream rotors even closer together when used on slopes. If possible it may be advantageous on slopes (when wind will be a factor) to space them close enough that they will actually spray over and past the next sprinkler head in each direction. This might seem to be overkill, but it is better than having plants die due to lack of water.
Unlike most rotors, stream rotors do not require the use of a different size nozzle when you need a different arc pattern (ie; a quarter circle pattern verses a half circle pattern.) Technically, this is because the precipitation rate does not change when you adjust the arc. So you can use the same nozzle for a quarter circle as you would for a half circle, assuming both have the same radius. Examples; if your stream rotors are all spaced 25 feet apart, they will all use the same nozzle size. If some are spaced 20 feet apart and some are 30 feet apart, you would want to use a smaller nozzle for the stream rotors with the 20 foot spacing.
Manufacturer's Performance Data:
The Hunter company has performance data on their MP Rotator website. See the MP Rotator website at http://www.mprotator.com/.
For an in-depth description of features found on this and other rotors, see the faq on "How to Select the Best Rotor-Type Sprinkler".
Text and Images by Jess Stryker unless noted. Copyright © Jess Stryker, 1997-2018. All rights reserved.