Nozzle Selection and Maintenance for Efficiency and Precision

 

Top color-coding makes it easy for contractors to verify proper nozzle installation. This image shows a black-topped 15-foot nozzle. Red, green, blue and brown tops have become standard for Rain Bird, Toro and some other 5, 8, 10 and 12-foot (respectively) nozzle tops.

Can You Mix and Match Sprinklers?

It?EUR??,,????'???s best not to mix different types of heads on the same circuit, because each type of sprinkler applies water at a slightly different rate. For instance, an impact sprinkler might apply 1/4 inch of water per hour, while a spray sprinkler might deliver 3 inches per hour. If they are on the same circuit, you may have to over-water parts of your lawn in order to get the right water coverage in other areas.

How Do I Clean my Pop-up Sprinkler Nozzles?

One of the advantages of modern molded plastic sprinklers is that they are easy to flush and clean. To remove the nozzle simply pull up the pop up part of the sprinkler (the stem) and the nozzle is on the very top. Holding tightly onto the stem with one hand, turn the nozzle counterclockwise until it separates from the stem. You do not need to turn the screw on top to remove the nozzle; it is just for adjusting how far the stream throws. As you remove the nozzle, you should see a screen inside the riser. Pull out the screen and rinse both the nozzle and screen in clean water. Never clean plastic nozzle orifices with wire or a wire brush because this can deform the interior passages and lower the quality of nozzle performance. If the nozzle is blocked and cannot be cleaned, you will have to replace the nozzle with another one of the same type. The type of nozzle is stamped into the top of the nozzle and is designated by numbers and some letters. A few examples of this would be “15H”, “9SST”, or “10VAN”. Before replacing the screen and nozzle, open the valve and flush out the head. Turn off the station, then put the screen and nozzle back into place and turn the zone back on. After this cleaning, you may need to re-adjust the direction of the sprinkler’s spray. You can make these adjustments by grabbing and twisting the stem (the part that pops up) left or right until the spray of water is confined to the area that needs to be watered. The stem may be somewhat difficult to turn and will make a ratcheting noise when turned, which is normal.

Using 30 percent less water, this plastic nozzle employs a second orifice for close-in watering and more uniform water distribution. The design cuts watering times, saves water and money and reduces waste.Photos courtesy of Rain Bird Corporation

How Do I adjust the Spray?

First look at the designation on top of the nozzle. Many of the nozzles have certain patterns and arcs that are non-adjustable. For example a 12Q nozzle will throw a twelve- foot long quarter of a circle (90 degree) arc spray. The only thing that can be adjusted on these fixed arc nozzles is the distance. To do this, simply turn the silver screw on the top of the nozzle to the left to increase the water flow through the nozzle. Turn it to the right (tighten the screw) to reduce the throw. The recommended minimum throw distance on the 15-foot nozzle is 10 feet. You can also aim the nozzle by firmly grasping and turning the pop-up stem. The stem incorporates a ratchet that will hold the spray nozzle in its new orientation.

Irrigation Insights

15-30: Psi, a good range of pressure at the nozzle on irrigation systems. Source: North Carolina State Extension Service

37: Percent, the highest recorded water savings in Douglas Community, Ga., after replacing nozzles on a series of rotating sprinklers. The average savings reported was 20 percent. Source: University of Georgia