Irrigation System Basics

Basic Terms

Controller:  Sometimes called the clock, this is “The brain” of the irrigation system. The controller is programmed to start the system at a given time, typically in the overnight hours. When it is time for the system to run it sends an electrical charge to the control valve it wants to open.

Control Valve: This is the valve that sits between the main line and the lateral lines. When an electrical charge is sent from the controller to the control valve, the valve opens and lets water go to the heads.

Main Line: This is buried plastic irrigation pipe that is connected to the water source on one end and to the control valve on the other. It is always pressurized while it waits for the control valve to open.

Lateral Line: This is buried plastic irrigation pipe that is connected to the control valve on one end and supplies water to the heads on the other end. This line is only pressurized when the irrigation zone is running.

Zone: A portion of the irrigation system that  has multiple heads that run at the same time. There is typically more than one zone on an irrigation system. Breaking the system into zones assures that enough water is available to allow all heads to pop up.

Rotor head: A type of irrigation head that pops up from the ground when pressurized with water. The top of the head rotates while spraying a directional stream water. The rotation allows it to cover its entire watering area.  This type of head is typically used for larger areas.

Spray head: A type of irrigation head that pops up from the ground when pressurized. This head has a fixed top so it sprays water over its entire watering area while running. This type of head is typically used for smaller areas

Drip Line: Porous tubing that is buried in the soil. When pressurized, the tubing drips water into the soil to add moisture. This type of irrigation is commonly used for shrubs and perennials that are planted in beds.

 

Basic  functions (Previously defined words are bolded)

Each irrigation system contains a controller (or clock), when the controller wants to start the irrigation system it sends an electrical charge to the control valve connected to the zone it wants started.

When the control valve receives its electrical charge it opens and allows water to run to the Rotor heads, or spray heads or drip line.

The Rotor heads and spray heads pop up and drip line drips to cover the water their watering area.

When the time for the zone is done the controller stops sending the electrical charge and the control valve closes which stops the heads from spraying.

The the controller will repeat steps 1-4 on the next zone that is programmed to run until all programmed zones have run.

 

Additional Considerations

Smart Controllers: Many irrigation systems now have smart controllers which adjust run times based on weather conditions. As a result, each day the zones may run a different length of time, may start at a different time or not at all.

Rain Sensors: Most systems contain rain sensors. They are set to stop the system from running when it rains the previous day. Rain sensors are typically set to shut down the system when ¼ inch of rain is received. Most passing rain showers do not exceed ¼ inch, so the system will still run the following night.

Watering Area: Most systems are designed so heads that pop up water turf areas only. If shrubs and perennials that are planted in beds are watered, it will typically be done with drip irrigation

Jeff-Wilson

Jeff Wilson | General Manager
Posted 05/24/2019