Tuesday, July 1, 2008

Hello again Craig!

I hope that all is well with you. I just picked up a few rotors and received 12 red nozzles to go with each. My question is how do I determine which nozzle is appropriate for a particular property?

I’m learning as I go on your lawn irrigation repair website and thank you so much for the support. Have a great week!

Nate S.

Hi Nate,

I'll try to make this explanation as basic as possible, as it could go on for pages. You can find more detailed information in the members troubleshooting Power Points section at www.IrrigationTV.com

Lets say you want to irrigate a square piece of turf that is 30 x 30 feet. In order to maintain an even amount of water over the area, each nozzle would be the same size (lets say 3 gallon per minute) because each head is watering a quarter of the area.

Lets say you are now watering a 30 x 60 rectangle of turf. Now you would have four heads in the corners watering 90 degrees, and two heads in the center watering 180 degrees. Because the center heads are watering twice the area, the nozzles need to be twice the size (6 gallon) to keep the precipitation rate even.

So if you have quarter, half and full circle rotors on the same zone, if the 90 degree heads have 3 gpm nozzles, then the 180 degree would have 6 gpm nozzles and the 360 degree would have 12 gpm nozzles.

The exception to this rule would be on zones that cover both sun and shade areas. A 90 degree rotor watering full sun would have the same nozzle as a 180 degree rotor watering full shade as the water requirement is roughly half for the shaded area.

Of course, in a well designed system you would not find this exception, because zones should be separated into hydro-zones (sun/shade zones). Unfortunately, well designed systems are the exception, not the rule.

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