Need Sprinkler Help

[cabinetman]

The drawing below shows the front of the house. The dotted area, marked "new area" was a gravel section we used for additional parking. We have since sodded that area, and now the sprinkler coverage is short. The markings "H" are half pattern, and "F" are full coverage. There is a ">>" for the direction of water source.

What I would like to do is add another head at the ends of four towards the front. The distance between existing heads is about 12'. What if any changes should I make, and PVC diameters that would work. The heads being used are the plain brass screw on from HD.
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[Rand]

The answer depends on how many Gallons Per Minute you are able to flow.

It appears to me that you already have a lot of heads on one circuit. Adding 4 more heads might reduce the pressure so much the system won't work anymore.

An easy solution would be to replace the heads near the new area with rotor sprinkler heads that have a longer throw.

[Uncle Cracker]

An easy solution would be to replace the heads near the new area with rotor sprinkler heads that have a longer throw.

Not as easy as you might think... You should not mix rotor heads with spray heads on the same zone, because the precipitation rate for rotor heads is only 25-30% of the spray heads. Hence, you would be overwatering the spray areas and underwatering the rotors, since the timing for both would be the same.

C-man, if you are planning to add four 12'-full-circle spray heads to your existing zone, then you are adding roughly 10-gpm to your supply requirement. Even if you have large enough piping, you may not have the surplus supply volume available to do this. I think you may need to add another zone. This may or may not be easy, depending on your distribution and control setup. If I knew more about the rest of your system, I could suggest the most doable means. Irrigation is my life...

[cabinetman]

If I knew more about the rest of your system, I could suggest the most doable means. Irrigation is my life...

I don't know if this will help, but the pump is 2 HP, and the run to the first head is about 25'. I'm open to any suggestion.
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[Chris_B]

Not as easy as you might think... You should not mix rotor heads with spray heads on the same zone, because the precipitation rate for rotor heads is only 25-30% of the spray heads. Hence, you would be overwatering the spray areas and underwatering the rotors, since the timing for both would be the same.

This is generally true, and mixing pop-ups and rotors definitely makes things more complicated.

However it *is* possible to get low-flow pop-ups that are a much closer match to rotors.
See http://www.hunterindustries.com/products/mprotator/ for a 8' minimum throw pop-up
and http://www.hunterindustries.com/Prod...otors/pgp.html for a classic rotor with 22' minimum throw.
In both cases, click on the "Charts" tab. The precipitation rates are remarkably close.

While certainly challenging in smaller areas, rotors are generally FAR better than sprays if you can manage the longer throws:
1) Precipitation rate is much lower (less run-off)
2) Very easy to adjust for angle and distance
3) Cover a much larger area with a single valve (lower flow)
4) Less affected by wind
5) Installation is much easier (less pipe/joints/heads).

From speaking with a few commercial installers, Hunter makes the best rotors, and the PGP is the most widely installed rotor in the US for commercial applications. The PGJ is also a good rotor (with 15' minimum throw), and mixes easily with PGPs.

I'd recommend against getting rotors at the big-box stores, as the ones they sell are apparently inferior. There are lots of places online with excellent rotors at good prices.

[Uncle Cracker]

I don't know if this will help, but the pump is 2 HP, and the run to the first head is about 25'. I'm open to any suggestion.
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I figure your existing zone is about 30-gpm total (those full-circle heads really add up). I would hesitate to add another 10-gpm to this without knowing your pump make, model, water source, vertical suction lift, and suction line size. Running 40-gpm through 1-1/4" pipe is gonna hurt your pressure also, so even if your pump gots the nutz, you'd be better off running a new line over to it across that 25+ feet for any new heads. Do you have a zoned system with a timer, or does what you show comprise your whole system?

[Uncle Cracker]

This is generally true, and mixing pop-ups and rotors definitely makes things more complicated.

However it *is* possible to get low-flow pop-ups that are a much closer match to rotors.
See http://www.hunterindustries.com/products/mprotator/ for a 8' minimum throw pop-up
and http://www.hunterindustries.com/Prod...otors/pgp.html for a classic rotor with 22' minimum throw.
In both cases, click on the "Charts" tab. The precipitation rates are remarkably close.

MP rotators are not giving great results in Florida, and I would certainly not recommend replacing all the spray heads with them. They have extremely small orifices and do not like water with any solids in it. They are also even more susceptible to wind disruption than fixed spray heads, regardless of the marketing propaganda. If you've seen them run, you understand why. We can get away with them in shrubbery here, but turf use is risky, at best.

[Wood_workur]

What if you break it up into two zones one on the left and one on the right. So you'd have to take the piece of pipe connecting them now, cut it, cap one side and run the supply to get to the right side to the begging of the circuit. Then you know that you are not gonna exceed any GPM ratings.