If you’re having trouble finding a PGP-ADJ, or you just want to try something different, there are a few rotors available that are a direct replacement for the PGP-ADJ. I’m Dwayne Smith, your Sprinkler Warehouse product specialist.

Finding & Replacing Hunter PGP Rotor Alternatives

You need to replace an old PGP-ADJ. The PGP-ADJ is an amazing rotor and it’s in high demand, but there are alternatives. In fact, there are alternatives that use exactly the same can as the PGP-ADJ, which makes swapping out a broken PGP-ADJ something you can do in just a couple of minutes. If you’re laying out a new sprinkler system and you need an alternative to the PGP-ADJ, these rotors are a great option. I’m talking about K-Rain’s RPS Select, RPS 75, and RPS 75i. If you’re not familiar with K-Rain, you should know they invented the reversing mechanism that is used in the Hunter PGP-ADJ. In fact, all other rotors are based upon that mechanism today. No matter what brand rotor you buy, you’re getting some K-Rain ingenuity in there.

Let’s look at these rotors alongside the PGP-ADJ. You’ll see they look very similar. All have very sturdy retraction springs. The can is identical – very sturdy. They’re the same height and have very similar watering distances. All of these rotors have a 40° to 360° arc just like the PGP ADJ. So, on to installation.

Installation

Before installing the new rotor, choose the correct nozzle for your rotor. It is a little easier to change out a nozzle before you get them in the ground, although changing the nozzle once it’s in the ground is not difficult. Maybe your rotor already has the appropriate nozzle. If it doesn’t, I’ll show you how to do that really quickly. We’ll begin by changing the nozzle on an RPS 75 or an RPS 75i. Nozzle change-out on these two is identical.

Changing RPS 75 & RPS 75i Nozzles

1. For this install, we’re removing the can from the rotor, which makes changing out the nozzle easier.
2. To access the nozzle just push down on the collar. Back out the nozzle retention screw. You want to get the screw all the way out from in front of the nozzle, but not so far that it falls out and you have to go looking for it.
3. Pull out the nozzle with a pair of needle-nose pliers.
4. When you insert the nozzle it will be going in at a downward angle. Pop in the new nozzle; tabs go up. Push it all the way in. Screw back in the nozzle retention screw. You want to screw it in far enough to just break up the stream of water – just barely in front of the hole in the center of the nozzle. This is ready to install.

The RPS Select is unique because it has four built-in nozzles. You change nozzles just by turning this selector here.
The idea of the RPS Select is to choose the nozzle that most corresponds to the arc setting you chose. So, if you’re setting the arc at 90 degrees, you’ll select nozzle number one. If it’s 180°, select nozzle two, et cetera.

Rotor Installation

Now for the quick and easy rotor change-out:

1. Unscrew the old rotor top and pull out the assembly. If the rotor can wants to come unscrewed as well, you can dig down a little bit and hold it in place wiht a strap wrench.
2. You’re going to want to install the rotor with the top facing a particular direction unless you’re replacing a full circle rotor. If the rotor you’re replacing is in the middle of the yard and will be going around a full 360°, you don’t have to do this next part (Step 3).
3. If the rotor you’re replacing will be less than 360° because it’s at the edge of your yard, you’ll need to find the right stop. These three K-Rain rotors all have a fixed right stop. That means if you increase the arc, say from 90° to 180°, only the left stop will change, not the right stop. To find the stop, hold it like this and turn the top back and forth several times to find the right stopping point.
4. When you insert the new rotor assembly, make sure that this little arrow – where the nozzles are – is aiming in the direction where you want the rotor pattern to stop on the right side. So, I want it pointing this directino so it stops at the path here.
5. Slide the guts down in the can, being careful to not get any dirt or debris inside. Tighten the top.

Isn’t that way easier than digging up the whole rotor? Now, adjust your pattern.

Adjusting Your Pattern

On the RPS 75 and 75i, you’ll adjust the pattern here. On the RPS Select, adjust the pattern here. Once you’ve got your pattern set, turn on the zone and adjust your watering distance. The water should reach the next head over. You adjust the watering distance by using the nozzle retention screw when using the RPS 75 or the RPS Select. The RPS 75i has a unique function I’ll cover in a second. Even if you want the maximum distance, you still want the nozzle retention screw down far enough to break up your watering pattern a little. See, like this [screw not breaking up water] versus this [nice water pattern].

RPS 75i

The RPS 75i has Intelligent Flow. That’s this little slot right here. This adjusts your watering distance also known as the radius. Intelligent Flow reduces the amount of water coming out of the rotor when you shorten the distance. That way you’re not wasting water by putting out the same amount of water for say 30 feet of distance as you would for 40 feet of distance.

RPS Select

The RPS Select is a really neat rotor with a couple of awesome features. As I mentioned before, it has four built-in nozzles, which you choose based on which pattern you’ve chosen. The reason for the nozzle change is it reduces the water use appropriately. You don’t want the rotor spraying water at the same rate for a 90° pattern as you would for a 360° pattern. Because then the portion of your lawn serviced by the 90° rotor will get four times as much water as all the lawn serviced by the full-circle pattern rotor.

The other feature I really like on the RPS Select is that it shows the selected pattern with this little arrow here. As you change the pattern adjustment right here. Over here, the arrow points to the degree arc you’ve chosen, takes out the guesswork, and saves you a little bit of time.

The next time you need an alternative to the PGP-ADJ, consider these K-Rain Rotors: RPS 75, RPS 75i, and RPS Select.

When you need to take your trees, lawn, flower beds, and gardens to the next level, Sprinkler Warehouse has the product and the knowledge to assists. If you have any questions, feel free to chat with one of our incredible customer service agents on sprinklerwarehouse.com. They really do know their stuff, and they’ll get you squared away. Subscribe to our YouTube channel for helpful tips, tutorials, and general sprinkler instruction.