How does an automatic sprinkler system work?
The following diagram provides a simple look at the anatomy of a sprinkler system. The starting point is the source of water for the system. In this case there is an existing supply from a city meter to the house. Local codes may regulate who and how you can tap into your source. A mainline pipe carries water from the water source to a backflow prevention device which helps keep the sprinkler system from potentially contaminating or polluting the drinking water.
Except for very small yards, the water pressure from the source is insufficient to allow watering of the entire yard at one time, so the yard is broken up into smaller areas called zones. An automatic sprinkler valve controls the flow of water from the mainline to each zone. The sprinkler valves are often grouped together in an arrangement called a sprinkler manifold which makes them easy to locate and reduces the amount of sprinkler wire required. The sprinkler wire connects each automatic valve to the sprinkler timer or controller. The sprinkler timer tells each valve to open at a specified time, run for a specified time, and then close. Some sprinkler timers can be connected to smart devices which automatically calculate when and how long the system should run and shut the system off when it is raining. The ability to precisely control watering according to specific conditions in the yard is the key to how an automatic sprinkler system conserves water. Lateral line pipes carry water from the automatic valves to the sprinkler heads. Drip zones, which use very low flow sprinkler devices called emitters to deliver water garden, shrub, and flower beds, are becoming more and more common as a water-conserving replacement for traditional sprinkler heads. The easiest ways to design a professional, water-conserving sprinkler system are to use the Orbit Sprinkler System Designer.