Rotors move water and move it quickly. Jeff Johnson, senior product manager for Rain Bird, gives LM his insights on why a rotor is a useful tool for irrigation pros.

LM: What do irrigation pros need to understand when designing an irrigation system with rotors? 

JJ: What you’re looking at is a single-stream water distribution device. A single stream is preferred for wind penetration and longer throws because the water stays together, and you get better distribution. So, when you’re looking at larger green areas — anything over 15 feet — a rotor is your best option.

LM:  What are some common questions you get from pros about rotors?

JJ: What’s the warranty? How long is it going to last? What’s the ease of installation and maintenance?

There are two types of contractors; one that goes in and installs and one that comes in after the fact and to do maintenance. The first contractor wants the rotor to go into the ground fast and install easily. They want to set the rotor up, set the settings for the throw, link it quickly and move on to the next one. The maintenance contractor wants to know how easy it is to clean debris out of the rotor. If I have to change the nozzle, how easy is that? Or are there any minor setting changes I need to make? 

Those are the two things I would say they look for both on the installation and on the maintenance side.

LM:  How should pros maintain their rotors? Are there specific parts that wear quickly?

JJ: There are not too many field-replaceable parts in a rotor. So, the first thing you can look at is the inlet filter screen. That cleans out any significant debris that comes in from the water source; it can be removed and cleaned or replaced. Beyond that, I would say the next easiest thing is to replace the guts of the rotor. Spin out the internals and then reinstall new ones. The next step would be to dig up and replace the full rotor. Changing the internals is probably the easiest and most common means of doing maintenance.

LM:  What are some common misconceptions about rotors?

JJ: Rotors tend to get a bad rap. If you go out to a large site, you might see a dozen rotors shooting 30 gallons a minute and people will go, ‘That’s a lot of water. Why don’t we tear all of these out and put in a drip system?’

But there’s a reason you’re putting down 30 gallons a minute, and you’re doing it in a sustainable way if you’re using the correct rotor. And it’s what the turf needs anyway, so even if you’re doing it with a subsurface system, the turf is going to need those 30 gallons.

LM:  Pressure-regulated spray bodies are a big talking point in the industry at the moment. Has that started to work its way into the rotor space?

JJ: It hasn’t yet, but our Rain Bird 5000 series rotors have pre-installed pressure regulation. We have a pressure-regulating swing joint for the larger rotors; pressure regulation can give 50 percent water savings. 

It can depend on the pressure and flow, but you’re saving a ton of water if you have a check valve — an internal valve that prevents external leaking — or a SAM (Seal-a-Matic) system. Without that, there’s a waste of water. That water is going somewhere that you don’t want it to go.