The basic components of automatic sprinkler systems are the same, whether you purchase a do-it-yourself system or contract with a professional service to have one installed.
The clock controller unit is the core of the system. It activates the sprinkler system according to selections you choose. There are two types of controller units: electro-mechanical clocks and digital read-out clocks. Electro-mechanical clocks have dials and pegs that let you set specific times, days and cycle durations. These clocks are durable and easy to use, but they are somewhat inaccurate, especially with cycles less than 10 minutes long. Digital read-out clocks are less durable and a bit more complicated to program, but are more flexible and accurate. Most new automatic sprinkler systems use digital read-out clocks.
The system operates from a central water supply line. This pipe, which is usually made of white polyvinyl chloride, commonly called PVC, runs from your water service line to your system’s zone valves.
Zone valves are solenoid valves that allow water to flow from the system’s main line, through smaller lines, and out sprinkler heads. Most systems have several zones, each controlled by one or more zone valves.
Lateral lines lead from the zone valves to the sprinkler heads. Lateral lines are usually made of black polyethylene pipe, or poly-pipe.