Automatic Sprinkler Components for Landscape Irrigation

If you are considering on building an automatic sprinkler system it's a good idea to understand the names of the various pieces and what they are for. Here is a list of the common sprinkler system components that you will find and might want to use for your system:

PVC or poly pipe — lays out the main lines of your sprinkler system and connects to the water supply line. PVC pipe is less expensive and more durable than poly. However, poly pipe is flexible, and can bend around corners without the use of joints.
Backflow preventer and anti-siphon valve — prevents sprinkler water from flowing back into the drinking water.
Sprinkler heads and risers — spray the water over the desired area. There are lots of types depending on the situation: impact, surface, pop-up head, bubbler head, and so on.
Connectors and fittings
Controller — turns the sprinkler system on and off at pre-set times. Sprinkler systems are usually divided into zones or circuits. The controller allows you to turn the different sprinkler zones on and off independently of one another.

Sprinkler Heads

Depending on the shape of the lawn, use different sprinkler heads to provide the best coverage. Typical sprinkler heads include:

Impact — ideal for watering large open areas. A mechanical arm hits the stream of water (you'll know it by the "tick, tick, tick" sound) which helps propel and distribute the spray upwards of 45 feet.
Rotor — gear driven sprinkler heads that rotate to cover wide areas.
Pop-up heads — are inserted flush to the ground and only rise above ground to emit the stream of water when activated
Bubbler head or spray head — ideal for smaller areas (up to 10 feet), such as flower beds

For more information on sprinkler systems please read this article, an overview of irrigation systems.