Application rate: Also known as precipitation rate. The rate at which a sprinkler applies water, usually given in inches per hour (iph).
Check valve: A device installed to prevent drainage from sprinklers at lower elevations. Usually installed under the sprinkler, but some sprinklers have this device installed already.
Flow rate: The manufacture-designed water discharge rate from a sprinkler, measured in gallons per minute (gpm). A micro-irrigation emitter's flow rate is measured in gallons per hour (gph).
Flushing: A method of clearing dirt and debris from piping and sprinklers. To perform, remove the last sprinkler head in the zone, turn on the zone for a few minutes to flush, and reinstall the sprinkler.
Head-to-head coverage: Efficient sprinkler coverage that throws water over 80 percent or more of the distance to adjacent sprinkler heads
Nozzle: The part of the sprinkler where water come out. Most nozzles can be interchanged to provide different flow rates or spray patterns.
Rain Sensor: Also known as a rain shut-off device or rain switch. A device that prevents the sprinkler system from turning on when there has been adequate rainfall. However, it does not interrupt the timekeeping function of a clock.
Rotary head: Also known as a rotor. This sprinkler type throws one stream or many streams of water while rotating, with many moving parts. Typically used to water large lawn areas, applying water at a slower rate than a spray head, from 0.1 to 0.3 inches per hour. Spacing in most residential systems is generally 25 to 35 feet.
Spacing: The distance between adjacent sprinkler heads.
Spray head: A stationary sprinkler head, generally with no moving parts, that pops up when water is supplied and down when it stops. Water is applied in a designated spray pattern at a rate from 1.0 to 1.5 inches per hour. Various nozzle types produce different spray patterns. Spacing is generally 3 to 15 feet. Some manufacturers have begun marketing rotary spray heads that offer head-specific adjustments to spray patterns and to water "throw" distance.
Time clock: Also known as a controller or timer. An automatic timing device, connected to a series of electric valves, that turns sprinkler zones on and off according to a schedule set by a contractor or homeowner.
Valve: A device that controls the flow of water into a zone. Manual valves, such as a gate or ball valves, need to be opened and closed by hand. Electric valves are wired to a time clock.
Zone: A group of sprinklers that operate at the same time and are controlled by a single valve.
* Adapted from a publication created by Christine Claus, St. Petersburg Water Resources Department, and Dr. Joan Bradshaw, University of Florida IFAS, with funding provided by the Pinellas-Anclote River basin Board of the Southwest Florida Water Management District.