SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Hello All,



Pretty much brand new to irrigation although I
have been trying to read as much as I can lately.



I am going to install a new sprinkler system this
fall before winter to be ready for spring and I am having a hard time trying to
figure out what rotors I should go with. Listed below is a little background of
what I am working with.



I took the bass ackwards approach and ran a
mainline out to the area where the valves would go. My service line is
3/4" as well as the meter. I tee'ed into the 3/4" line after the
meter and rain a 1" pvc line to the valve location. Doing a pressure test
and GPM test at the valve location, I have 80 PSI at 15GPM. My area to water is
very simple. It is basically a 90'X90' square.



I was "planning" to do 4 zones with 16
heads total at 30' a distance. The Zones would look like below.



1. 90, 180, 180,90

2. 180,360,360,180

3. 180,360,360,180

4. 90,180,180,90



I "planned" to use the Hunter i20 rotors
with a 4GPM nozzle. Using the 4GPM nozzle, seems like I would only be able to
get .25" an hour down per zone. I've already purchase hunter jartop
1" valves. Does this seem right? Would you change anything? Do anything
different?

Quoted from "hi.todd"

""I would use the Rainbird 5000 series heads.""

I was looking at the 5004 with Pressure control. Do you think the pressure control is a good feature and worth while considering my pressure is 80PSI right off the bat?

So I went ahead and mocked up one zone with 1" pipe and 4 Orbit Heads that I bought from lowes just to make sure that my design looked good. I used pvc and connected the 3/4" female inlet head to a female 1"x1"x3/4" femail tee via a male 3/4" adapter. I got decent coverage but not as much as I expected using the 4gpm nozzle. I was only getting around 27 feet. I was wondering If I need to step down the inlet pipe to the head to get better pressure? Am I way off in my thinking?

Quoted from "Wet_Boots"

Yes, you are way off in your thinking.

It is now safe to assume you have overdrawn your account, so far as pertains to system flow. Remove all the nozzles and try a size smaller. That would be two 3 gpm nozzles for the middle heads on a zone, and two 1.5 gpm nozzles for the end heads. (since we are assuming you now are using 4 gpm and 2 gpm nozzles)

Before doing anything, take more pressure measurements. Again, with the system off, and then, with the zone turned on.

okay, I figured as much. What's the easiest way to accomplish the pressure test withthe zone on? I have a boiler drain after my manifold for draining purposes. Can I check static pressure there with a pressure gauge and test it there as well while the zone is on?