# MP rotator question



## Maritimer 99 (May 31, 2021)

I'm thinking about pulling the trigger on an irrigation system for a lawn I'm planning to install next year. I don't know much about irrigation systems so I'm trying to get my ducks in a row.

I'm looking at getting Hydrorain HRS 200 bodies and installing MP 3500 for nozzles. My question is,

Hydrorain HRS 200 accept female threaded nozzles, and I believe on the hunter website their male nozzles are not available on MP 3500. I just want to be certain that my set up will work before I order them. Anyone with knowledge on the two I would appreciate their approval.

Thanks!


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## bernstem (Jan 16, 2018)

Spend the extra 4 dollars per spray body for pressure regulated spray bodies from Hunter or Rainbird.


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## Maritimer 99 (May 31, 2021)

bernstem said:


> Spend the extra 4 dollars per spray body for pressure regulated spray bodies from Hunter or Rainbird.


The difference in price for my order is $45 which isn't what I was going for. I like the fact that I can change the pressure regulator from 30 psi to 40 with the twist of a screw driver. Are they not a very reputable brand?


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## bernstem (Jan 16, 2018)

Maritimer 99 said:


> bernstem said:
> 
> 
> > Spend the extra 4 dollars per spray body for pressure regulated spray bodies from Hunter or Rainbird.
> ...


I have no direct experience with them, but they do not have as good a reputation as Hunter or Rainbird.

Why do you want to change the pressure after installation? The heads are designed to work best at 40 PSI. If you need to decrease throw distance, you can do it at the head without changing precipitation rate. I honestly can't think of a reason to need a lower pressure on some heads but not others or to change pressure after install.


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## Maritimer 99 (May 31, 2021)

bernstem said:


> Maritimer 99 said:
> 
> 
> > bernstem said:
> ...


My knowledge of irrigation is very limited. But I was thinking that if I ever want to switch nozzles down the road that operate better with 30 psi it would be a nice option to do so.

I was also thinking that if I don't have the pressure necessary to operate the system I could run it on 30 psi until I have the funds and means to install the necessary booster pump near the lawn. It is about 100 ft from my house and I'm on a well. Not sure if that is a legitimate concern.


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## bernstem (Jan 16, 2018)

Maritimer 99 said:


> My knowledge of irrigation is very limited. But I was thinking that if I ever want to switch nozzles down the road that operate better with 30 psi it would be a nice option to do so.
> 
> I was also thinking that if I don't have the pressure necessary to operate the system I could run it on 30 psi until I have the funds and means to install the necessary booster pump near the lawn. It is about 100 ft from my house and I'm on a well. Not sure if that is a legitimate concern.


There isn't much difference between 30 and 40 PSI for many spray nozzles. I wouldn't worry about running a 30 PSI nozzle at 40. FWIW, I have MP rotators on unregulated spray bodies and they work just fine.

As for pressure, you do have a small pressure drop from a regulated head. That can impact performance if you are borderline in pressure. You should measure pressure and calculate pressure losses before installing anything. The same for flow rates. https://www.irrigationtutorials.com/#gsc.tab=0


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## burntfire (Dec 10, 2020)

@bernstem is absolutely correct.

Before you try to spec out a system you should first calculate your flow and pressure. At that point you can send it in to Rain Bird for a free design or see if your local irrigation supply house knows any designers.

You can worry about the extra $45 or more in parts now or the $100s in repairs/re-designs in the future when the system doesn't work properly.


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