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
These are the parts of a lawn sprinkler system, drawn as a front yard from above with the house at the top, and then one sprinkler head in the ground, cut open.
Read the full guide
Around the yard
The controller on the house wall is a timer. When a zone is due, it opens that zone's valve in the box by the house, and water runs through the buried pipes to that zone's sprinkler heads. A soil moisture sensor tells it when watering is not needed.
At each head
The sprinkler body is the case buried in the ground on the end of a pipe. It holds the nozzle, which sprays the water onto the lawn.
Leaks often show up at the joints between the sprinkler heads and the pipes: look for soggy patches.
Questions and answers
What are the main parts of a sprinkler system?
The controller, the zone valves it opens and closes, the pipes, and the sprinkler heads, each a body with a nozzle. Some systems add a rain or soil moisture sensor.
What is a zone in a sprinkler system?
A group of sprinkler heads that water together, switched on and off by one valve.
What does a smart sprinkler controller do?
It uses local weather data or a soil moisture sensor to change the watering schedule, so it does not water when the plants do not need it.