# System Design for SCGrassMan



## SCGrassMan (Dec 17, 2017)

So I am doing a front yard and a back yard for somebody.

For the back yard, it's a 17x44 area. I have been working with limited flow from a well which we are working to improve upon. In the meantime, I am proceeding with the system design based on how many heads are needed, and calculating flow etc.

I plan on feeding each zone with 1" PEX. Then, I can either use 1" Schedule 40 PVC for the zones themselves, or more PEX.

I am leaning towards Option 3, which has:

4xMP1000-90s
6xMP1000-180s
2xMP1000-360s

I came up with 4.62 GPM for this layout, using the 40 PSI numbers. The well is putting out 6 GPM at 30 PSI, so the flow rate through those heads will actually be slightly less than that. Those heads are rated for 8-15' between heads, so with this layout they are all 9-11 feet apart.

Pic is below.


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## SCGrassMan (Dec 17, 2017)




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## zeus201 (Aug 30, 2017)

Option 3 is my vote.


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## g-man (Jun 15, 2017)

The MPs use a 40psi body. If your pump is 30psi, it wont lift the bodies. Hunter does sell a 30psi body, but your radius is reduced (per the tables). Again, if the pressure at the bodies is less than 30psi (likely with all the friction losses), then the nozzle will not lift.


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## SCGrassMan (Dec 17, 2017)

g-man said:


> The MPs use a 40psi body. If your pump is 30psi, it wont lift the bodies. Hunter does sell a 30psi body, but your radius is reduced (per the tables). Again, if the pressure at the bodies is less than 30psi (likely with all the friction losses), then the nozzle will not lift.


Hmmm.... will not lift at all? Are you sure? The tables show it at 30 PSI, but I wasn't sure if that meant I needed to get the 30 PSI bodies. I think it will hit 40 PSI at less than it's full flow rate.


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## SCGrassMan (Dec 17, 2017)

I should also state that while I don't know how well it was running because there were a lot of broken pipes, this setup WAS using MP rotators before with this same pump.


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## J_nick (Jan 28, 2017)

g-man said:


> The MPs use a 40psi body. If your pump is 30psi, it wont lift the bodies. Hunter does sell a 30psi body, but your radius is reduced (per the tables). Again, if the pressure at the bodies is less than 30psi (likely with all the friction losses), then the nozzle will not lift.


I'm not sure about this. I think they just limit the psi to 40 at the heads.


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## SCGrassMan (Dec 17, 2017)

Yeah I'm 80% sure that's the case. I guess I can hook it all up after designing as best I can, and then just letting the well guy figure out how to get me the flow I need lol


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## g-man (Jun 15, 2017)

I had that wrong. I found the info. It was hard to find. The min pressure for the bodies is 15psi, max is 100psi. The radius for the mp nozzles is a function of the psi. Their tables only go to 30psi.


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## SCGrassMan (Dec 17, 2017)

g-man said:


> I had that wrong. I found the info. It was hard to find. The min pressure for the bodies is 15psi, max is 100psi. The radius for the mp nozzles is a function of the psi. Their tables only go to 30psi.


Yeah they have from 30-55 psi listed, so I was just building based on 30 PSI.

The real challenge is going to be another area which I will draw out in a minute.


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## SCGrassMan (Dec 17, 2017)

Here is the second area, which isn't to scale, but is labeled with accurate measurements. I don't know what to do in that semicircular area to get head to head coverage.

This area also concerns me from a GPM POV. I was thinking maybe a semi circle of sprays facing inwards from the edge on a separate zone. But this whole area is full sun so it definitely needs water.

I could also do a second 360 head in the middle, or maybe 4 feet south of the other 360 set to 8 feet so there is at least overlap for that head.


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## Greendoc (Mar 24, 2018)

Add 270s to the corners entering the semicircle area. Place MP 1000s fanned out to cover the area starting where the arc of the 270s ends. Three should do it.


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> Add 270s to the corners entering the semicircle area. Place MP 1000s fanned out to cover the area starting where the arc of the 270s ends. Three should do it.


Can you draw a little pic of what you mean?


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## Greendoc (Mar 24, 2018)

I need that guy that was all over yahoo news to teach me how to draw on a tab. But the 6 additional MP 1000s should be spaced such that they cover one edge but do not overspray onto the hard surface outside.


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## SCGrassMan (Dec 17, 2017)

Oh I gotcha. So by 270s you just meant on those two corners, and then the 3 extras in that semicircle, maybe somewhere in the 90 to just less than 180 degree range? I count 5 extra and not 6, did I miss one?

And thanks as always. I'm thinking this is gonna have to be two zones with my existing GPM issues, or we will just have to bite the bullet and put that bigger pump in.


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## Greendoc (Mar 24, 2018)

5 it is. 270 goes on the corners and then the others on the arc are between 90-180. Split it. If anything, I would run the half circle of the area special and not as part of the rest of the irrigation system. In case that area is affected more by wind or hot concrete. I am having a hell of a time right now managing a 5000 sq ft Zeon lawn. Zones are split up in such a way that some of it is too dry or some is too wet. I need to put into pictures how it was configured. The South side of the lawn goes right up to the beach. East side faces into the wind.


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> 5 it is. 270 goes on the corners and then the others on the arc are between 90-180. Split it. If anything, I would run the half circle of the area special and not as part of the rest of the irrigation system. In case that area is affected more by wind or hot concrete. I am having a hell of a time right now managing a 5000 sq ft Zeon lawn. Zones are split up in such a way that some of it is too dry or some is too wet. I need to put into pictures how it was configured. The South side of the lawn goes right up to the beach. East side faces into the wind.


yeah, I have a special hatred for the strip along my neighbors yard and along the sidewalk. Despite specifically INSISTING I wanted head to head coverage.

So I'm looking at the JRS10 pump and the GT15 pump. Without knowing what the specs of the WELL are, I know its getting 6 GPM, so if I look at the GT10, which is also 1 HP, and follow the performance guide chart to 6 GPM, it *could* be that its trying to pull 120 feet of "Total Dynamic Head". In which case, the GT15, at that same amount of head, should do close to 20 GPM.

Does half a horsepower make that big of a difference? And also, it seems like its a lower pressure pump at 20-40 PSI than the current one, which is 40-60 PSI.

Lastly, OK on the heads. Its actually completely surrounded with boxwoods, so they won't mind the extra water.


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## Greendoc (Mar 24, 2018)

If surrounded by boxwoods that is a special case yet again. Areas covered by greenery/shade need less water. GT15 pumps are high head pumps made for running irrigation.


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> If surrounded by boxwoods that is a special case yet again. Areas covered by greenery/shade need less water. GT15 pumps are high head pumps made for running irrigation.


I guess what I'm saying is, is before I tell this lady she needs a new outlet run and a $400+ dollar pump, is this likely to get me where I need to be flow wise? Best guess, working backwards from getting 6 GPM from the other running at 115V presently.


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## Greendoc (Mar 24, 2018)

Yes. You need this. Also, MP Rotators are optimum when you have 40 PSI at the heads. less than that you give up close in coverage and distance. Other thing to think about is how harmful it is to dead head or restrict flow out of a low head pump. Hooking up her present pump to the MP Rotator irrigation system may burn it out. Not as much of a problem when using Rainbird or Toro fixed head sprays at 3 GPM a piece at 25 PSI. Using MP Rotators will increase the back pressure.


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> Yes. You need this. Also, MP Rotators are optimum when you have 40 PSI at the heads. less than that you give up close in coverage and distance. Other thing to think about is how harmful it is to dead head or restrict flow out of a low head pump. Hooking up her present pump to the MP Rotator irrigation system may burn it out. Not as much of a problem when using Rainbird or Toro fixed head sprays at 3 GPM a piece at 25 PSI. Using MP Rotators will increase the back pressure.


Ok, sounds good. I appreciate your input as always man, your knowledge with this stuff is unmatched.


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## SCGrassMan (Dec 17, 2017)

Does it matter that I'm plumbing it for 1.25" on the inlet and 1" on the output side instead of the 1.5" it's set up for by default?


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## Greendoc (Mar 24, 2018)

Not really. As long as you are not exceeding flow velocities for the pipe size. Remember that pump inlets and outlets should not be plastic of any kind. Meaning PVC or other plastics connect to the system after so much copper, brass or steel.


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> Not really. As long as you are not exceeding flow velocities for the pipe size. Remember that pump inlets and outlets should not be plastic of any kind. Meaning PVC or other plastics connect to the system after so much copper, brass or steel.


Thanks for that, that's a good point. That explains why they have metal on both before changing to plastic.

Also we got lucky - turns out it's already wired for 230V, so all we have to do is change the pump out.

I told her if that doesn't fix it, the well guy will have to take a look, but had her order the GT15.

The JRS10 is like a year old so we may try and sell it.


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## SCGrassMan (Dec 17, 2017)

So for those interested. We have ordered the well pump, and I have completed the system design with some help in this thread. I have opted to go with Blu-Lock 1" tubing from Sprinkler Warehouse.

I want to say my final count was 34 heads, and 850 linear feet of tubing. Blu-Lock is all snap together fittings. The Tee fittings are nice because they have a 1/2" threaded connection to attach the swing arms to.

Also went with a 4 zone hunter valve manifold pre built. I probably could have built one myself and even saved a few dollars, but it seemed like a good idea to just get one already done.


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## Greendoc (Mar 24, 2018)

Glad it came together. Did you fire it up yet?


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## SCGrassMan (Dec 17, 2017)

Greendoc said:


> Glad it came together. Did you fire it up yet?


Waiting on all of the parts. Blue Lock listed a local vendor as carrying it, I drove 40 min (without calling my fault) and they're like "Do we carry what?!?"

I was fully prepared with part numbers, etc. but I ended up ordering them online.

There was a misunderstanding and the customer only just ordered the pump yesterday. So probably next week sometime. Then I can level the dirt and order the sod!


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