how to Add a Rotor or Spray Head to an Existing Irrigation Zone
If you have increased the size of your garden, you can add new risers and heads to a irrigation zone as long as you have left room for growth. If the existing zones cannot handle more output, or the devices you want to add do not have the same flow rates as those already installed, you will need to add a new zone to the system.
Adding Irrigation / Sprinker Risers
You can add new risers to an existing circuit (zone) in two ways: either along an existing line of PVC pipe or on a new line you branch off from an old line. The steps below will show how to add risers to an existing line.
Locate the spot where you want to add a riser. Dig very carefully down to the pipe, making a hole wide and deep enough to work with the pipe easily without getting soil into the system. Using PVC ratcheting cutters, cut out a section of the PVC pipe wide enough to insert an adjustable slip-fix coupling and a tee fitting with a threaded outlet for the riser.
Install Fittings Cement the slip-fix to one cut end of pipe and the tee to the other. Adjust the fittings to fit the space as necessary. Make sure to plan ahead so that the tee is facing straight up; remember that solvent cement dries very fast.
Attach the Riser Using the appropriate height and type of riser for the location (here we use a Hunter Swing Joint Riser), wrap the riser threads with pipe-thread tape and screw the riser into the tee fitting.