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FIREPLUG1111
03-18-2009, 04:25 PM
I'm getting ready to install a irrigation system in my yard. My question is-- the rainbird rotorary head sprinklers I have, have a 3/4" inlet. I was going to run 1/2" pipe to the head. ( downsizing as I go along starting with 1") Do I need to run 3/4" pipe to the heads or will 1/2" work?
Thanks Alan

TRILAWNCARE
03-18-2009, 04:44 PM
I'm getting ready to install a irrigation system in my yard. My question is-- the rainbird rotorary head sprinklers I have, have a 3/4" inlet. I was going to run 1/2" pipe to the head. ( downsizing as I go along starting with 1") Do I need to run 3/4" pipe to the heads or will 1/2" work?
Thanks Alan

How many heads per zone are you planning on running and pressure will answer the question of what size the pipe needs to be?

What are the specs for your system static pressure, GPM, Pressure loss, type back flow device, number of zones, number of heads per zone, distance for each zone and so on..... Or did you not figure all this out yet?

Dripit good
03-18-2009, 05:52 PM
( downsizing as I go along starting with 1") Do I need to run 3/4" pipe to the heads or will 1/2" work?
Thanks Alan

No need to downsize, save yourself the trouble. Your working pressure will be better if you don't. Stick to 1" on all your runs.

More importantly are you going to answer TRI?

Did you do your homework??

TRILAWNCARE
03-18-2009, 06:02 PM
More importantly are you going to answer TRI?

Did you do your homework??

But I was watching the Sprinkler Daddy video and....................:hammerhead::hammerhead::hammerhead:

FIREPLUG1111
03-18-2009, 10:10 PM
TRILAWNCARE:
I'll try and answer your questions.

#1 Each zone will have a different amount of heads. That is determined by the area they are covering. Example. My side yard will only have 5 heads all with 1/2 radius coverage. My back yard will have 9 heads 4 of which will be full radius and 5 will be 1/2 radius.
#2 Pressure, My pressure will be between 50 and 65 psi . My pump is putting out an average of 35 GPM at the pump.
#3 Friction loss FL=C,Qsq,L. That cant be determined until water is flowing.
#4 No back flow device its on a well pump.
#5 Not sure how the number of zones determine the size of pipe. But I have 7 zones.
#6 See #1
#7 See #1
#8 distance to the farthest zone is about 155 feet.

FIREPLUG1111
03-18-2009, 10:12 PM
DRIPIT GOOD:

Thanks for your answer short and to the point. I will run 1" pipe and hit the heads with 3/4"

Thanks for your answer.

Alan

Stuttering Stan
03-18-2009, 10:15 PM
Assuming you did the design correctly, will you have a matched precipation rate throughout every zone? If you don't know what ths means, do more homework. It's vital to ensure a quailty system.

unit28
03-18-2009, 10:19 PM
If you don't get #3 before you do #1 then I would get someone who can do #2 to flow better.

FIREPLUG1111
03-18-2009, 10:44 PM
Stan:
Yes I did my calculation on precipation rate. The half radius heads will have a different size nozzle compared to the full radius nozzles. Most likely half the rate on the half radius compared to the full radius. I dont want puddles on my half radius coverage.

FIREPLUG1111
03-18-2009, 10:46 PM
UNIT28:
My pump is pretty much a constant I really cant change that. I can only suck so much water out of the ground at one time.

TRILAWNCARE
03-18-2009, 10:53 PM
TRILAWNCARE:
I'll try and answer your questions.

#1 Each zone will have a different amount of heads. That is determined by the area they are covering. Example. My side yard will only have 5 heads all with 1/2 radius coverage. My back yard will have 9 heads 4 of which will be full radius and 5 will be 1/2 radius.
#2 Pressure, My pressure will be between 50 and 65 psi . My pump is putting out an average of 35 GPM at the pump.
#3 Friction loss FL=C,Qsq,L. That cant be determined until water is flowing.
#4 No back flow device its on a well pump.
#5 Not sure how the number of zones determine the size of pipe. But I have 7 zones.
#6 See #1
#7 See #1
#8 distance to the farthest zone is about 155 feet.

Here is a friction loss calculator. http://www.irrigationtutorials.com/sprinkler09.htm

Study some of the other parts of the web site for determining pipe size, and pressure lose.

Just don't go over the specified feet per sec. velocity for the size pipe you are using. If you are close to max, then it is best to jump up a size off the valve. Or use less heads on that zone.

Looks like you have plenty of GPM and PSI to start with. What size mainline are you planning on using? I would not go any smaller than 1 1/4 on the mainline.


Calculate it all out and let us know what you come up with.

And like Dripit good mentioned, use all 1" preferably schedule 40 on your laterals. 1/2 " for watering flower pots.

And don't forget swing joints on each head or at the least funny pipe.

unit28
03-18-2009, 10:59 PM
what he said...just remember 5 feet per second.

TRILAWNCARE
03-18-2009, 11:01 PM
UNIT28:
My pump is pretty much a constant I really cant change that. I can only suck so much water out of the ground at one time.

Do you know what your well is rated at?

If you run at max. capacity you will suck it dry.

Study the Country Bumkin (http://www.irrigationtutorials.com/sprinkler04.htm) area of the website as well.

Also is this the same well that you drink out of????

You sure have a lot of homework.......

FIREPLUG1111
03-19-2009, 08:41 AM
Nope not the same well I drink out of. Its a shallow well. And pretty much got all my homework done. This aint my first rodeo just a different bull...

Sprinkus
03-19-2009, 08:42 AM
Is the well pump activated by pump start circuit or are a pressure switch and pressure tank involved? If the latter then the system should be designed so that the pump does not cycle on and off while the system is running.
Unless you want to replace your pump frequently.
Also, a backflow preventer should be used to prevent possible contamination of the well.

unit28
03-19-2009, 09:04 AM
Grab a 250 gal. poly tank for reserve.
Need Air gap for filling it.
Raise it so the bottom is 48" minnimum above highest head.
Your well pump will love you better in a different kind of way.

This ain't no roady-o padna. FL needs to be calc'd before you ride for Glory

TRILAWNCARE
03-19-2009, 09:41 AM
Nope not the same well I drink out of. Its a shallow well. And pretty much got all my homework done. This aint my first rodeo just a different bull...

Ya, I see that from these threads. Running a pump full blast does not work to well. Did you ever get that one figured out?

http://www.lawnsite.com/showthread.php?p=2559376#post2559376

http://www.lawnsite.com/showthread.php?t=246546