A blank nozzle is available as part of the Low-Angle Nozzle Set (PGP-ADJ P/N: 233200 & PGP Ultra/I-20 P/N:356605SP), which can be inserted into the rotor to shut off the flow of water.
The riser will still pop up as if the rotor is going to water so be sure not to use the plug as a permanent alternative to properly capping off head. These nozzles should be used as temporary plugs to help flush lateral lines and assist in maintenance procedures. The blank nozzle must be removed if the system will be winterized. Capping or removing a sprinkler must be done differently if the area you live in requires winterization.
PGP Ultra/I-20 Nozzle Rack with Shutoff Nozzle
PGP-ADJ Nozzle Rack with Shutoff Nozzle
The PGJ does not have a blank nozzle to shut off flow to one rotor. If you want to shut off one PGJ rotor, use a ½" plug to cap off the sprinkler head. These PVC parts are available at most local hardware outlets.
The I-20 has built-in FloStop Technology that allows the flow to be shut off at the rotor. The Flo-Stop is the hole in the center of rubber cover. When the I-20 is operating, insert the Hunter Adjustment Tool and turn clockwise until the flow of water stops.