Tag Archives: nozzles

Jul 31 2012

In the Time Before Plastic there was Brass.


There was a time when brass nozzles where all you saw in irrigation systems. Why? Well, there were no plastic ones. Hard to imagine pre-plastic, isn’t it?  You had brass, zinc and steel. Brass dominated because of its looks and durability.

The first generation or three of plastic nozzles were rough. Manufacturing technology was not at the level needed to produce a truly efficient, uniform pattern spray nozzle. If you wanted quality and efficiency you went with brass.

Today’s plastic nozzles are very efficient and provide good, uniform coverage. Many of them provide coverage as consistent as brass nozzles. They are also cheaper than brass. Why, then, would people continue to buy brass? There are a number of good reasons.

Normally about now I’d start throwing some numbers and statistics at you to show you why this product is so much better. Not today.  I will note that brass nozzles are available with a 24’ radius. Plastic nozzles tend to stop at 15’.

Our wonderful graphics group had absolutely nothing to do with this graphic.

Why buy brass?

Well, if you are designing a system and can space heads every 24’, as opposed to every 15′,  you save on parts and labor. Parts may be cheap but labor is not. Eliminating heads while maintaining coverage can make a noticeable difference in your costs.

Durability. It’s easy to find brass nozzles 50 years old still in service. Brass is corrosion resistant, withstands hot and cold easily, and resistant to abrasion from debris.  If you see a plastic nozzle 15 or 20 years old you have found an exceptional system.

Abrasion resistance. As clean as it is, your water can still carry sand and other debris. Even with municipal water there can be fine sand and, in some areas, metal particles from inside your old galvanized supply line. When metal pipes break down they tend to do it from the inside out, releasing abrasive metal particles into your water. This fine abrasion can have a cumulative effect on any nozzle. Plastic, being softer than brass, will show wear far earlier. The particles will also adhere to the side more readily, causing a build-up that has to be cleaned more often than brass.

Hot and cold. REAL hot and REAL cold. Extreme temperatures: brass has survived them just fine for centuries. Get cold enough and plastic can get brittle. Fine if no one bothers it until it warms up again, not so fine if someone steps on it.

And the main reason people still buy brass nozzles: they look good. Architects don’t recommend brass for door handles, desk trim, railings, faucets, lighting, fountains and more because it’s the latest thing. They use brass because it looks good and stays looking good for a long time. Brass gives everything a classic, finished look.

You work hard to make your place attractive. Very few parts of your irrigation system show to the public. Shouldn’t those parts reflect the pride and work you have in the rest of your home and last just as long?

Jul 11 2012

Specialty nozzles to nuzzle.


Ok. Not nuzzle. Couldn’t think of a good title. Some people say I never do.

I’ll get down to business. Most people know about the average, used everywhere nozzles. If you don’t then check out sprinkler nozzles. These generally do the job and are all most people will ever need.

There are a number of specialty spray nozzles available for increased water efficiency, problem areas or special applications.  Normally I avoid naming particular brands and products, preferring to give general information. This is the exception.

The first is the Toro Precision Series spray nozzle. While this is not technically a specialty nozzle it has some advantages over competing spray nozzles. The Precision Series has something they call H²0 technology which puts an oscillation on the spray . I’m sure the H20 name has nothing to do with the scientific name for water. Pure coincidence.  Anyway, quoting Toro, “Using patented H²0 chip technology – and no moving parts – each Precision Series Spray nozzles creates one or more high frequency oscillating streams to achieve the desired arc and radius with 1/3 less water usage.”  Yup. Sounds cool. But looks even better.

Ok. Pretty pictures and lots of marketing fluff don’t mean much without the facts. Comparing the Toro Precision nozzle to two major competitors:

Radius/ Feet Pattern GPM @ 30 psi Difference GPM
Toro 15 Full circle 2.31 —–
Brand A 15 Full circle 3.72 +1.41
Brand Z 15 Full circle 3.70 +1.39
Toro 15 Half circle 1.16 —–
Brand A 15 Half circle 1.86 +.70
Brand Z 15 Half circle 1.85 +.69

You might ask “If these are so good, why aren’t more people using them?”  Good question. Thanks.  The only downside to these nozzles appears to be the price. The Toro Precision sells for roughly 2.5 times the cost of standard nozzles. That can make noticeable difference in installation costs for an entire system. However if you are in a retrofit or repair situation and need to have better control over your precipitation, fix a zone that has been expanded beyond capacity, or control run off on slopes they offer you some valuable options.

Let’s talk about Rain Bird Rotary Nozzles.  These cover a radius of 13 to 24 feet. Their big advantage is the ability to match these to the Rain Bird 5000 rotor series and get the same precipitation rate.  Let’s say you have a large area that will be covered by rotors and a small area next to it, say 20’ x 20’. Normally the smaller area would require its own zone using spray heads on pop ups. With Rain Bird Rotary nozzles you can now cover the area with one zone and get the same precipitation rate. Use the 5000 rotors for the large area, the rotary nozzles for the small one. You’ve eliminated one valve, the wiring and one zone requirement on the controller.

Because of their low precipitation rate they are very good for watering slopes. The slower precipitation rate gives the soil more time to absorb the water, minimizing run off.

Next is the Rain Bird U-Series.  In a perfect system you have head to head coverage. Most sprays do well on the far  coverage but lack real coverage in the first couple of feet out from the nozzle. Head to head coverage means that the area missed by head A is now covered by head B. In many cases, due to poor design, changing landscape or deteriorating systems, this no longer occurs and you get dry areas around the head. The U-series has a second nozzle for greatly improved close in coverage. While not as good as head to head coverage it sure comes close.

This is beginning to sound like a Rain Bird advertisement. Not intentional, it’s just the way the nozzle sprays…

Now we have the lovely and talented Rain Bird SQ series nozzles. The SQ stands for square pattern. These put out a true square or rectangular pattern with edge to edge coverage. Most square pattern nozzles aren’t. On that I can speak from experience.

The SQ offers two settings so one nozzle throws 2.5′ or 4′, changeable with a simple twist of the top ring. It has a pressure compensator built in and fits standard pop ups and risers. It is also pretty low flow, using only .46 gallons per minute at its largest setting. Having a square pattern helps eliminate the waste that occurs when you try to match half and quarter circles to cover a narrow rectangular pattern.

And remember, if you are getting enough rain you need to muzzle your nozzles. Get a sensor.

Jul 5 2012

The sprinkler rotor keeps moving and the spray head won’t budge. Which one is right?


Congratulations. You just bought a football team. Now you have a football field to water. You decide to use pop up spray heads with a 15’ radius. You can get a very efficient pattern of coverage with only 147 spray heads. Of course, you’ll constantly repair them as the players will stomp them into the ground. If, after a tackle, a player comes up with a spray nozzle in his nose I extend my sympathies to you.

How about planting a flower garden? Oh, about 6’ wide x 20’ long. Now I’ll use a rotor to irrigate it. For highest efficiency I’ll plant the rotor about 20’ past the end of the garden, spraying back in. I’ll also set it’s rotation to the standard minimum 40o angle, which means it also waters an extra 21’ of yard at the end of its arc. Hope that doesn’t hit your sidewalk.

People get confused about which type of sprinkler to use. On the one hand rotors put out a lot of water and move all around. Must be good, right?

Spray heads have a fixed radius, usually 15’ or less, and just serenely apply this efficient fan of water. No wasted movement, no back and forth agitation. Must be good, right?

The decision on which to use is simple. Answer these questions and the answer falls into place.

1. Is your distance less than 25’? If so, go with popup spray heads. The most popular rotors can’t get any closer than 22’, usually 25’ plus.

2. Wide open area? More than 25’ each direction? Rotors would work.

3. In a planter? Spray head

4. Following the curve of a walkway? Spray head

5. Narrow strip between houses? Spray head

6. Open area now, as in question #2, but you intend to put in planters later? Spray head

7. Football/baseball/soccer field? Rotors

8. Around your deck and pool in back yard? Spray head

The differences

Rotors are designed for open areas. They spray a large volume of area in a back and forth motion, either full or partial circle. Typical distances for residential are 22’ to 50’. There are some that will go down to 15’ but these aren’t normally used in good efficient designs. They are usually used to fix a problem somewhere or to help compensate for a bad design.

Spray heads are usually used on pop up bodies. They spray a consistent amount of water over a fixed area. They are available in various radii and patterns, along with adjustable pattern spray heads. This makes them very adaptable to any situation. In the eight questions above, notice that only two indicate rotors. Also that #2 and #7 are essentially the same thing, so only one situation fits rotors. After that, it’s spray heads.

Or drip. But there is already an article on that.