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

Hi there,

Heredown an irrigation plan with the datas. Is this feasable with 2 circuits or do I have to consider 3 circuits ?

Thanks for your comments about this project.

The plan can be viewed here as well :

http://img697.imageshack.us/img697/7610/print4forum.jpg

Quoted from "Wet_Boots"

It is difficult to do a picture-perfect design on an irregularly shaped property. No head in the middle of the lawn? You have a dry spot in the making. A crafty veteran would move head #8 from its current location to one where it could do a larger half-circle, and cover the center of the lawn.

Hi Wet_Boots,

Thanks a lot for your comment. Yes, I am aware about the dry spot. I don't want to have a spray in the middle of the lawn but I didn't have the idea about a 180 - 30 feet head for #8. Actualy, regarding the sun exposure, it make more sense even if I don't move it from its current place. And I could change the #12 and reduce its circle. Thanks

What do you think about the GPM of each circuit against the GPM I have (~1800 a circuit vs 2200). This is ~20% of loss and I have read somewhere you have to count on 25% of loss. Do you think I am too short and should consider 3 circuits ?

Quoted from "Wet_Boots"

Make your system connection, then measure the flow and pressure it provides. Only then will you know if your design is correct.

??
I know already the flow and pressure where the manifold for my pipes will connect (measured : 9,7 gpm - 58 to 72 PSI).
My issue is to know if with ~9,7 gallons per minute flow and 58 to 72 PSI pressure, 2 circuits are sufficient. One needs 8,25 gpm and the other 8,8 gpm. Pressure is in my opinion not an issue in my case as the sprinklers I choose need ~50 psi. On the paper, everything works fine. But I have read somewhere that I have to count on 25% flow loss. This would mean that from a 9,7 gpm there is in the reality only ~7,3 gpm available. This would mean that 2 pipe circuits are not sufficient and should consider in my design a third one.

In your opinion, is the flow loss of 25% realistic ?


Well sorry for the mistake in my previous post I jump from metrics liter to gallons inches, etc.. . Of course, when I say 1800 gpm, I thought 1800 liter per hour.

Quoted from "Wet_Boots"

Frankly, with the 'requirement' that there be no heads in the middle of the lawn, I would not use MP Rotators.

Well this a not a requirement, it's a wish. Actually, I am reconsidering it with my different drawings I have made. I am more and more on a solution with a spray in the middle.

Do you know where I can get a documentation how to calculate the pressure loss, considering the pipe size and diameter, T pipe elbow, connected sprays, etc... ?