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Old 04-25-2013, 08:17 PM
iTom iTom is offline
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Too many head for a zone?

Hello,

I currently have a zone near my driveway with 6 heads in it. The sidewalk grass never had irrigation in it and I am planning to extend the driveway zone to the sidewalk. According to my calculations, I would need 7 spray heads to cover the sidewalk grass. These would probably be Hunter heads (the ones designed for sidewalks) The first 6 heads are all spray heads and the water line runs downhill, so I don't think much pressure is being used. So is 13 low velocity spray heads running down hill too much for one zone? My area has good water pressure by the way. If there is not enough pressure, is there some valve or gadget out there that will give the necessary boost?

Thanks!

Tom
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Old 04-25-2013, 08:26 PM
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1idejim 1idejim is online now
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Start by finding your supply (GPM)

Next, calc your demand (GPM)

Measure your pressure (PSI)

A little math will tell you.
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Old 04-25-2013, 08:26 PM
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Mike Leary Mike Leary is online now
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Quote:
Originally Posted by iTom View Post
If there is not enough pressure, is there some valve or gadget out there that will give the necessary boost?
I'm dreaming that you have some spare controller wire and a mainline close, it should be a separate zone.
That has been the biggest problem I've seen in amateur systems; never planned for expansion.
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Old 04-25-2013, 08:28 PM
bx24 bx24 is offline
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You need to do some homework on what is "good pressure", pressure lose(s) at locations, nozzles per zone, GPM before and after backflow, after valves etc....

Putting in systems is like working at walfart with some basic math but you are a little off.
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Old 04-25-2013, 08:30 PM
iTom iTom is offline
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Okay, I will run the numbers. I can't really run another zone because it would require a trench to be dug 270 degrees around the house to the valve box. The landscaping is already in. Ouch.
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Old 04-25-2013, 08:33 PM
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mitchgo mitchgo is offline
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From a profession standpoint and the actual right things to do

Couple things to factor:

Measure your Static Pressure
Measure your Dynamic pressure when the zone is running

- It would be nice to know your maximum water flow rate. Though just keep it standard to water flow rates for pipe size
-Calculate your current water flow on the zone
-Inspect Water meter size, More importantly inspect zone pipe size.
-Follow water flow rates based on pipe size and FPS ( Feet per second) Try to keep it under 5-7 FPS to help prevent water hammer ( Follow flow chart guide)

- Can the pipe that you are extending support the additional water flow to the requirement of the new sprinkler head addition? Can the entire zone support this much usage with out going over recommended FPS?


If there is spare wire available, spare room on the controller you can add a zone.
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Old 04-25-2013, 08:35 PM
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1idejim 1idejim is online now
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Quote:
Originally Posted by iTom View Post
Okay, I will run the numbers. I can't really run another zone because it would require a trench to be dug 270 degrees around the house to the valve box. The landscaping is already in. Ouch.
You have to understand that we can't see the system or do any testing. you have to do the leg-work
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Old 04-25-2013, 08:36 PM
iTom iTom is offline
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Quote:
Originally Posted by 1idejim View Post
You have to understand that we can't see the system or do any testing. you have to do the leg-work
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I do. I will hook up a gauge and check it out.
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Old 04-25-2013, 08:37 PM
bx24 bx24 is offline
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Quote:
Originally Posted by iTom View Post
Okay, I will run the numbers. I can't really run another zone because it would require a trench to be dug 270 degrees around the house to the valve box. The landscaping is already in. Ouch.
I ran into this situation on my own house. Had to run around 200ft of 1.25" pipe around my house to a 4-zone valve manifold to avoid pressure drops etc. That is part of the game. Not to hard if you do it correctly and not hack it. In the end, 107 Hunter heads and pipe cost me $1,800 and running pipe (1/4 mile) was about 2.5 hours with tractor attachement; can pull pipe at 8 mph!!!! All the sprinkler people wanted $8,000 to $10,000 to install...RIP off. Sorry I was in the business. Just as bad as he fert people.....$800+ for $200 of product.

Last edited by bx24; 04-25-2013 at 08:43 PM.
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Old 04-25-2013, 08:40 PM
iTom iTom is offline
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Quote:
Originally Posted by bx24 View Post
I ran into this situation on my own house. Had to run around 200ft of 1.25" pipe around my house to a 4-zone valve manifold to avoid pressure drops etc. That is part of the game. Not to hard if you do it correctly and not hack it.
It's not hard for the most part other than the multiple walkways, flower beds, steps, cement, and driveway I would have to dig under. I'm really hoping there is enough pressure.
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