Controller (timer)The timer that turns each zone on and off on a schedule. Smart controllers use local weather or soil moisture to skip watering when it is not needed.
Zone valvesElectric (solenoid) valves, one for each zone. The controller opens one to water that zone.
PipesBuried pipes carrying water from the valves to the sprinkler heads. Leaks often start at their joints.
ZonesThe areas watered together. Each is switched on and off by its own valve.
Soil moisture sensorA soil probe that tells the controller how wet the ground is. The controller can then skip watering when the soil is already moist.
Sprinkler bodyThe outer case of the head, holding the nozzle. It is buried in the ground and connected to the pipe.
NozzleThe tip on top of the sprinkler body. It sprays the water onto the lawn.
How this list was compiled: Read 2026-09-27. (1) US Environmental Protection Agency, WaterSense: Sprinkler Spruce-Up, https://www.epa.gov/watersense/sprinkler-spruce : irrigation controllers; sprinklers, pipes and valves, with leaks at the joints; sprinkler heads. Irrigation Controllers, https://www.epa.gov/watersense/irrigation-controllers : weather-based controllers and soil moisture-based controllers (soil moisture sensors). Spray Sprinkler Bodies, https://www.epa.gov/watersense/spray-sprinkler-bodies : the sprinkler body, the shell that connects to the piping and houses the spray nozzle. (2) Wikipedia, Irrigation sprinkler, https://en.wikipedia.org/wiki/Irrigation_sprinkler : a network of valves, pipes and sprinklers; sprinklers grouped in zones turned on and off by a solenoid valve; timers and smart controllers, rain sensors and soil moisture sensors; fixed spray heads and nozzles. Licence: own work
The drawing: Drawn for this site by script, 2026-09-27. Own work, nothing traced. Licence: own work
How it works
An unlabeled sprinkler system diagram on one sheet. The upper drawing is a front yard seen from overhead, house along the top. The lower one is one sprinkler head sliced through in the soil. No name is written on either.
Read the full guide
Five lines on the yard
Three leave by the left edge. From the top they are zone valves, the pair in the box by the door; pipes; and zones, the two lawns either side of the path. Two leave by the right edge: controller, the box on the house wall, and soil moisture sensor, the probe standing in the right-hand lawn.
Two lines on the sprinkler head
The left one ends on the case sunk in the soil: sprinkler body. The right one ends on the small cap the spray fans out from: nozzle. The stem between the two takes no name here.
The twelve dots round the lawns are sprinkler heads from overhead. None has a line: the lower drawing names a head's two parts.
Another sheet may print timer for controller and solenoid valves for zone valves. Each pair names one part.
Questions and answers
What is the difference between a sprinkler head and a nozzle?
A sprinkler head is the whole sprinkler. Its body is the outer shell that connects to the piping and houses the nozzle, and the nozzle is the part that applies the water. On this sheet each has its own line.
How many zones does a sprinkler system have?
As many as it has zone valves: one valve and all the sprinklers it turns on make a zone. The sheet shows two, a lawn on each side of the path, and a single line stands for both.
Is a backflow preventer on the sprinkler system diagram?
No. A backflow preventer, rotor heads, drip lines and a rain sensor are not drawn. The house, the path, the valve box, the wires and the spray are drawn and take no name.