# My system design



## Buyanet (Feb 4, 2019)

So I just received my Design back from Rainbird .... I am glad I did a new one because to be honest, my old one wasn't really that well of a drawing. Anyways, attached you'll see their design.

Couple of questions:

1) Looks like 7 Zones (7 valves). Why in the world do they have 2 of them in my Front Lawn? No way I am putting a Valve box in my Front Yard

2) 3/4" Pipe? Haven't I been reading that 1" is best? My Water Meter IS 5/8".

3) No backflow preventer device is on this parts list, unless I am missing it? That'd obviously have to be added too, correct?

4) The 7th Zone (or Zone 4 on this drawing) is a low pressure valve for a drip line. Honestly, the little piece on the side of my house doesn't really need a drip line. I could, technically, adjust the spray head on Q1 in front of it to spray further, therefor reaching this space? It's 3 rose bushes.


My plan is to purchase a little at a time and once have everything, I'll go to town with installing this myself with the help of 2 neighbors.

Thank you for any insight you may have to share! Getting all the parts will take me some time, but I plan on keeping this thread updated, unless I abandon ship with this, :lol: :lol:


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## nathan99218 (Jul 18, 2018)

The Valve box does not have to be where it says on the map I think its just a reference. You can always place it somewhere else. But I don't think you want to go super far with it because I think you can get pressure friction loss. I did the rain bird design also and I was confused my main is 3/4 and they want me to use 1'' at the POC I'm not sure why? I'm sure someone can tell us. haha. For the back-flow you need to check your local code to see what they recommend. I'm excited to see your progress with this. I plan on taking on the same task this summer also! Good Luck! I'm sure some other people will have better answers than me. haha


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## g-man (Jun 15, 2017)

The larger the pipe diameter, the less friction losses you will have as the water flows thru it. But friction losses are a function of distance too. So longer runs will benefit from a larger pipe diameter.

In the bottom left it states the design is for 10gpm and 60 psi per zone. A 3/4 PVC is safe to handle 11gpm. Their part list has nozzles in the 30 to 45 psi range. I think you should be ok with the 3/4. I would use 1in for the main and 3/4 for the laterals. If you want, calculate the flow for all zones (add the nozzles gpm for each)to be sure it is well below 10gpm.


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## SCGrassMan (Dec 17, 2017)

They are likely separating the front due to flow reasons. The only tricky part is going to be running all those zones before sunrise - that's a lot of zones.


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## Buyanet (Feb 4, 2019)

SCGrassMan said:


> They are likely separating the front due to flow reasons. The only tricky part is going to be running all those zones before sunrise - that's a lot of zones.


In my mind, it seems like it too. My parents old house had 5 zones and about 1/4 more area to water than me. Granted, their backyard was just a big square. I don't know a thing about irrigation, so even looking at the coverage map looks way overkill to me. My backyard "main area" (without adding in the sides of the house) is only ~25' x 52', or 1,300 sq ft, but 8 heads.

The purple zone in the front yard next to the driveway, the area is 80' long but only about I think 7' at it's widest point, shouldn't pop up umbrella sprinklers work just as well? I mean, 19 heads for that area .... holy smokes.

I almost think, while probably not completely saturated like this design, that I could get away with almost only half of the sprinklers. Sure, there won't be double or triple coverage, but water will still hit the spots ..... no?


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## SCGrassMan (Dec 17, 2017)

It is definitely not overkill. That's what a properly designed system looks like. It makes sure ALL of the grass gets wet and in equal amounts instead of "here's some sprinkler heads that will probably get your grass wet enough"


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## Buyanet (Feb 4, 2019)

SCGrassMan said:


> It is definitely not overkill. That's what a properly designed system looks like. It makes sure ALL of the grass gets wet and in equal amounts instead of "here's some sprinkler heads that will probably get your grass wet enough"


You seem to have a lot more knowledge than me when it comes to this, so I'll take your word for it, haha. I'll get everything on this list.

I'll also be needing a Backflow Preventer, which surprisingly isn't on this list. Also instead of the Controller Rainbird listed, I'll probably go with the Rachio 3 with Wireless Flow Meter (or maybe they'll have a Rachio 4 by the time I am done purchasing all this stuff).


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## Buyanet (Feb 4, 2019)

g-man said:


> The larger the pipe diameter, the less friction losses you will have as the water flows thru it. But friction losses are a function of distance too. So longer runs will benefit from a larger pipe diameter.
> 
> In the bottom left it states the design is for 10gpm and 60 psi per zone. A 3/4 PVC is safe to handle 11gpm. Their part list has nozzles in the 30 to 45 psi range. I think you should be ok with the 3/4. I would use 1in for the main and 3/4 for the laterals. If you want, calculate the flow for all zones (add the nozzles gpm for each)to be sure it is well below 10gpm.


Thanks! When you say for the main, you mean from the Main POC to the valves, and the laterals as in the ones going from the valves to the sprinkler heads?

I've calculated all Zones (besides 4 in this drawing as I won't be doing that), and came out to:


Zone 1:
4x H1 = 5.2
4x H3 = 2.08
1x E = 0.61
*TOTAL: 7.89 GPM*

Zone 2:
1x Q = 0.93
4x Q1 = 2.6
2x H1 = 2.6
2x H3 = 1.04
*TOTAL: 7.17GPM*

Zone 3:
4x Q1 = 2.6
4x H1 = 5.2 
*TOTAL: 7.8 GPM*

Zone 5:
3x 4A = 3
4x 3C = 6
1x 3B = 1.1
*TOTAL: 10.1 GPM*

Zone 6:
2x Q1 = 1.3
4x H1 = 5.2
2x H3 = 1.04
2x Q3 = 0.52
*TOTAL: 8.06 GPM*

Zone 7:
3x Q3 = 0.78
13x H3 = 6.76
2x S = 2.42
1x E = 0.61
*TOTAL: 10.57GPM*

Looks like they're exceeding the 10 GPM on Zone 5 and 7, should that be cause for concern?


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## SCGrassMan (Dec 17, 2017)

@Buyanet what you want is the Zurn Wilkins 975XL2 in either 3/4 or 1". I also opted for a screw in strainer because it was less than $40 and it was "people also bought".

As for the design, over 10 GPM is not cause for concern if you have 15 GPM available. That's a key detail to find out. Call your town water supply - those guys know a ridiculous amount of specific info down to the street.

I love my Rachio. I have a gen 2 installed, and a gen 3 new in the box with flow meter I just haven't gotten around to putting in.


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## Buyanet (Feb 4, 2019)

@SCGrassMan Thanks! I'll definitely be looking at that Backflow Preventer.

Call me dumb here and uninformed, but I just looked at the Parts list more closely. They have piping and fittings all at 3/4", but some Sprinkler heads (most) are a 1/2" inlet? Most swing arms are also 1/2". Now in my mind, a 1/2" isn't going to fit into a 3/4" fitting and the "Fittings/Accessories" list isn't listing anything in 1/2" either. So how in the world is a 1/2" Swing arm supposed to fit into 3/4" fittings. I am guessing they just didn't list the 3/4" x 3/4" x 1/2" F Tees etc.?

What am I missing here?

Sorry, just planning this in my head way ahead of time so I don't purchase everything on this list blindly, start putting it together and having a "How in the world" moment.


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## SCGrassMan (Dec 17, 2017)

It's common to have a 1/2" outlet on those for swing arms. The Tee fittings allow for it.


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## Buyanet (Feb 4, 2019)

SCGrassMan said:


> It's common to have a 1/2" outlet on those for swing arms. The Tee fittings allow for it.


Walked into Lowe's and played with the fittings. Funny, the 1/2" swing arms fit the 3/4" tees, but one end of the 3/4" swing arms is so tiny, it doesn't fit the 3/4" Tee, but it does fit the 3/4 SOC 1/2 F Tees. Makes sense to me now. I just have to visually look at things for them to make sense.

Prices seem much cheaper purchasing at Lowe's vs the Rainbird store by the way.

Speaking of prices, on the list provided by rainbird it has me purchasing 54 of the "
1804LN - 4 in. 1800 Series Spray Head - No Nozzle" for $2.43 a pop, and then also a bunch of nozzles as you can see like the "8 ft. Half-Circle Pattern Nozzle (180 Degree)" for $2.14 a pop. That's a total of $4.57. Wouldn't this Spray Head be the identical thing? Adjusts 8'-15', Half Circle 180 Degree, and it's only $3.19. That ~$1.40 difference adds up when you buy a bunch. Or am I wrong again on this? Thanks for all your insight! You're in Charleston, I might have to buy ya a cold one some day!


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## SCGrassMan (Dec 17, 2017)

I use only hunter stuff and buy from amazon or a sprinkler outlet store. Get the hunter brand swing joints and not those, just trust me.


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## J_nick (Jan 28, 2017)

I've heard the models they sell at Lowe's and HD are a little different than say their store or Ewing.


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## Buyanet (Feb 4, 2019)

J_nick said:


> I've heard the models they sell at Lowe's and HD are a little different than say their store or Ewing.


Interesting. I'll have to stop by Ewing and get the other 32SA from there to see if I can tell a difference or if it lists different model/part number.


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