# Hunter MP Rotators



## V35B (Jul 23, 2019)

Question- The guy that I have contacted to set up and install my sprinkler system is recommending Hunter MP Rotators (MP 3000) an d the 40 PSI regulated bodies. This will be used on a new seeded 18,000 sqft Bermuda lawn going in next spring. He has them in 2 zones, and I have 40 GPM at 60 PSI of water feeding this from a 2" line. He has 1" PVC running between heads. Zone 1 has 14 MP 3000 heads- 4 90 deg., 6 180 deg., and 4 360 deg. Zone 2 has 15 MP 3000 heads- 3 90 deg, 8 180 deg, and 4 360 deg. Does this seem like there should be more zones? Will the 1" PVC let all the heads perform as needed? What about reliability, are these good components? More info need for an answer?


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## g-man (Jun 15, 2017)

With 2in main, 40gpm, I don't see a problem with running only 2 zones. The components are good.

But, one small negative of just two zones is that you are forced to water all your lawn. For example, the north shaded areas will need less water than the south. Adding more zone will give you flexibility.


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## V35B (Jul 23, 2019)

Makes sense, Thanks.


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## dpainter68 (Apr 26, 2017)

V35B said:


> Question- The guy that I have contacted to set up and install my sprinkler system is recommending Hunter MP Rotators (MP 3000) an d the 40 PSI regulated bodies. This will be used on a new seeded 18,000 sqft Bermuda lawn going in next spring. He has them in 2 zones, and I have 40 GPM at 60 PSI of water feeding this from a 2" line. He has 1" PVC running between heads. Zone 1 has 14 MP 3000 heads- 4 90 deg., 6 180 deg., and 4 360 deg. Zone 2 has 15 MP 3000 heads- 3 90 deg, 8 180 deg, and 4 360 deg. Does this seem like there should be more zones? Will the 1" PVC let all the heads perform as needed? What about reliability, are these good components? More info need for an answer?


I would have to go back and reference some charts, but that flow rate with only 1" pipe concerns me. The 2" sounds right, so my question is when is it going down to 1"? I had about 23 gpm and stayed at 1 1/4" until I dropped below (I believe) 16ish gpm for CL200 PVC. The pressure loss and velocity through the pipe would be extremely high on anything above 20 gpm for 1" pipe.


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## hsvtoolfool (Jul 23, 2018)

I agree that water hammer may be an issue with only two zones. Look at the Jess Stryker irrigation tutorials and run the numbers. The math is easy. You just need to sum each nozzle's GPM to get the total for each zone. Then look at your pipe size. Jess has "rule of thumb" tips for safe velocities. In theory you've got the flow to run over 10 to 15 MP3000 together, but water hammer damage can cost you in the long run.

One advantage of more zones is flexibility. You can water dry areas longer and low, shaded wet areas shorter. Look at your elevations to see if it's worth factoring that in. Finally, you can adjust your schedule across more days. Just spitballin' ideas. Please keep us posted. Sounds really cool!


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## corneliani (Apr 2, 2019)

V35B said:


> Question- The guy that I have contacted to set up and install my sprinkler system is recommending Hunter MP Rotators (MP 3000) an d the 40 PSI regulated bodies. This will be used on a new seeded 18,000 sqft Bermuda lawn going in next spring. He has them in 2 zones, and I have 40 GPM at 60 PSI of water feeding this from a 2" line. He has 1" PVC running between heads. Zone 1 has 14 MP 3000 heads- 4 90 deg., 6 180 deg., and 4 360 deg. Zone 2 has 15 MP 3000 heads- 3 90 deg, 8 180 deg, and 4 360 deg. Does this seem like there should be more zones? Will the 1" PVC let all the heads perform as needed? What about reliability, are these good components? More info need for an answer?


I've just completed my own design & install with all MP Rotators and happen to have the spec book next to me. Running your zone output numbers you're running approx 30 gpm per zone. If you're truly getting 40 gpm then technically you have enough flow to push all these heads at once, but I would bring up a couple points worth considering.

1 - The Friction Loss Charts recommend an ideal flow of 5 FPS (assuming CL200 pvc), with the Irrigation Tutorials saying 7 fps up to max 10 fps if everything is super carefully designed. At the 30gpm you're designed at, 1" pipe is pushing 9 FPS. Water hammer should be a concern at this flow rate, as the others mentioned. 1.25" pipe would allow for that same gpm with a more tolerable 5.57 fps velocity.

2 - why use MP Rotators over such a large area? I would think that lawn rotors like the PGP or i20's would be more efficient (less pipe due to greater head spacing) with similar precipitation rates as the Rotators. For ex, the blue standard nozzle can throw 38' and still remain under 0.50 in/hr precipitation rate, and the water stream would be less susceptible to wind, etc, as it's a more concentrated stream vs the fine streams of the Rotators.

Lastly, I've been told that rotors are less finicky and prone to issues compared to the Rotators, simply due to the physical build & design (Rotator tips are more finicky with pressure, dirt, etc).

I don't mean to sow doubt as i'm completely new at this but I've literally spent the past month reading up on this stuff. If you're using an experienced group and they've done this kind of stuff before I would trust them, but if there's any reason you have to split off a zone and reduce the total GPM of the zone you'd be better off. If you would be maxing out a contoller and didn't have the room for another zone, maybe push it. But for a $15 valve and $25 worth of pipe, I dunno. I'd want to be very very sure everything is calculated perfectly. The risk/reward doesn't seem favorable.


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## V35B (Jul 23, 2019)

All good info, thanks. I am going to ask about the other heads. The velocity concerned me right off the bat, I always used 5 ft/s as a rule of thumb.


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## unclebucks06 (Apr 25, 2018)

18 gallons per minute max on 1". Your way over that.


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## hsvtoolfool (Jul 23, 2018)

corneliani said:


> Lastly, I've been told that rotors are less finicky and prone to issues compared to the Rotators, simply due to the physical build & design (Rotator tips are more finicky with pressure, dirt, etc).


Forgive me if I've said this elsewhere, but I disagree strongly that MP Rotators are "finicky" or "more prone to issues" than rotors. Irrigation companies have been making, selling, and supporting these gadgets for many years. If they were that much trouble, they'd be off the market by now.

Search the web for any type of irrigation gear (or brand), and you will find tons of complaints and problems for all head types. I suspect the root cause is poor system design and/or implementation and that most chronic issues are due to water hammer. Water hammer especially seems to be an issue that "pro" installers are either clueless about or just don't care about. This thread is a good example! Excess water velocity probably won't cause problems during a 1-year warranty period. So why should installers care if nozzle gears break, rotors gears are jammed, pipes burst, or valves stick open two or three years later?

MP Rotators (and regular spray heads) are certainly more sensitive to dirt contamination than large rotor nozzles. However, that issue is easily resolved with a primary 100 mesh filter before the valve manifold and a thorough system flushing during install. Granted, you may want to avoid using spray heads or MP-Rotators with non-potable water sources that are more likely to contain sand and rocks. You'd probably need to clean the filter several times a year.

Overall, we don't have enough details about the OP's yard to tell if their yard is a poor choice for MP-Rotators, just that there's way too much GPM for two zones. I also thought I-20s may be a better choice given his 18K SF size, but I assumed the areas are broken up by landscaping. My back yard is presently an open square at 10K SF. If I planned to leave it that way, I'd likely use Hunter I-20s and never look back. But after I build a garden shed, add a large patio and mulch beds, the MP-Rotatars are a no-brainer for me.


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## corneliani (Apr 2, 2019)

@hsvtoolfool

You may be right about the reliability / finickiness of the Rotators, I was passing along what the irrigation guy at SiteOne told me.. mind you he's the same guy who looked long at me when I asked about using the PSR40 heads. He said nobody uses those, only in very rare and unique situations.. and the box of heads I picked up (at half price, mind you) would confirm that as it had been sitting on the shelf for a couple years already! So you may have a point about the design being more of an issue than the product... BUT I can completely foresee having more issues with a spray head like the Rotators vs a gear-driven rotor. I dunno. It's in my head now.

As for the choice of i20's vs Rotators... he has 30 MP3000 heads covering 18k sqft. What is that, 600 sqft pet head?? it's gotta be open space in order to cover that much area. I'm super curious to see the design now cause I ended up with 30+ MP2000 heads covering 6,250 sqft. (200'ish sqft per head).


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## hsvtoolfool (Jul 23, 2018)

corneliani said:


> ...I was passing along what the irrigation guy at SiteOne told me.


I don't know about your SiteOne store, but the guys at my store just run the cash registers. They're nice folks. they mean well, and I really like my store overall, but I don't really listen to their advice any more. They steered me into buying an expensive, incorrect surfactant because they were out of what I actually needed. I got home and researched and saw it was wrong for my needs. I got a refund soon as possible and ran to Tractor Supply for their 80/20 surfactant. In the future, I'll just read what my TLF comrades have to say.

By the way, your SiteOne may be different, but my store charges 4X to 5X for Hunter irrigation products relative to on-line prices, or even a local irrigation company. I can buy a bag of MP-Rotator nozzles for what my local SiteOne store charges for ONE nozzle! I don't know if it's just Hunter products or all irrigation stuff, but I don't bother going to the irrigation counter at SiteOne for any more. Weirdly, that's the only area where SiteOne is crazy expensive. They have very fair prices for chems, fert, tools, etc. Go figure!



corneliani said:


> As for the choice of i20's vs Rotators... he has 30 MP3000 heads covering 18k sqft. What is that, 600 sqft pet head?? it's gotta be open space in order to cover that much area. I'm super curious to see the design now cause I ended up with 30+ MP2000 heads covering 6,250 sqft. (200'ish sqft per head).


I also wish the OP would put up a diagram of his property. Without it, there's no point guessing how they might arrange the heads or which type is best. Is it wide open? Are there paths, sheds, pools, and landscape beds to avoid? Of course, we are assuming correct head-to-head coverage. The OP's installer may not care about water hammer, but we also can't discount that he's planning to use half the total heads actually required for even irrigation.

In theory, the MP3000 and MP3500 can shoot about the same distance as a I-20 rotor at around 30 to 35 feet. I have no experience with those extreme MP3x00 nozzles, but I would overlap them by at least 2 or 3 feet since those specs are always optimistic. But the flow requirements at 3.6 GPM is just appalling since the 360° head sprays the entire area all a once.

On the other hand, the I-20 offers a 1.5 GPM nozzle which can shoot 30 feet (in theory) and has about the same precipitation rates as the MP3x00 nozzle. So I agree 100% that the I-20 may be a much better choice from lower flow rates (1.5 vs 3.6 GPM) and better wind resistance. I'd still overlap the I-20 heads by 1 or 2 feet just to be safe. The distance specs are always under ideal no-wind conditions.


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## jayhawk (Apr 18, 2017)

The last few irrigation CO's I've dealt with would only use a pressure regulated, check valve (PSR40) if you insisted.....otherwise it's a rainbird 1800 all day @corneliani. Residental contractors ...you wonder what gets them out of bed each day, clearly not into their work


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## Thor865 (Mar 26, 2018)

jayhawk said:


> The last few irrigation CO's I've dealt with would only use a pressure regulated, check valve (PSR40) if you insisted.....otherwise it's a rainbird 1800 all day @corneliani. Residental contractors ...you wonder what gets them out of bed each day, clearly not into their work


All of my bodies are rainbird 1800. Never ran into any problems that I can tell


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