Lawn Sprinkler System
AAtmospheric Vacuum Breaker (AVB) - a backflow prevention device installed between the remote control valve and sprinklers in non-continuous pressure applications. Must be mounted at least 12" higher than any sprinkler head or other downstream outlet.
BBackflow Prevention Device - a device that prevents water from re-entering the potable water supply once it flows into the lawn sprinkler pipes. A backflow prevention device is required in most areas. Check with your city offices to determine which device(s) are required in your area. Three examples are: Pressure Vacuum Breaker (PVB), Atmospheric Vacuum Breaker (AVB), and Reduced Pressure Device (RPZ).
CController - aka "timer," this is the device that sends electronic or hydraulic signals to the control valves for actuation.
Coverage - the area where a sprinkler head sprays water. This concept can be applied to a zone of sprinkler heads and to the entire irrigation system.
Control Valve - aka "zone valve," this is the component in the sprinkler system that regulates the on/off of water flow from the main line to each zone of sprinkler heads. Control valves are opened and closed by the controller. (Note: This is the only point in the system where the water supply and the electric signals meet.)
DDesigned Operating Pressure - the pressure a designer uses to calculate the flow rate and spacing for sprinkler heads. This pressure is determined by subtracting the calculated friction loss from the measured dynamic water pressure.
Distance of Throw - the distance a sprinkler throws water from the sprinkler to the end of the spray (radius); measured in feet.
Dynamic Water Pressure - aka "Running Pressure," this is the force water exerts on a piping system when the water is flowing; measured in PSI. Dynamic pressure will always be less than Static Water Pressure.
EEvaporation - the name for the process of converting any liquid to a gas or vapor.
FFan Spray Sprinkler - a sprinkler head that sprays water in a uniform "fan like" pattern. This "fan like" spray spreads water across the sprinkler's entire spray pattern all at once. Most fan spray sprinklers have a fixed spray pattern which is determined by the nozzle threaded into the top of the sprinkler. Some fan spray sprinklers have adjustable nozzles where the spray pattern is adjustable. Distance of throw is adjustable on almost all models and is usually 30-40' maximum radius.
Flow - the movement of water through the irrigation piping system. This motion causes friction loss.
Flow Control - an optional device on control valves that restricts the flow of water through the valve. Most flow control devices are adjustable from 0-100% of available water flow.
FPT - an abbreviation for "Female Pipe Thread."
Friction Loss - the loss of pressure due to contact between flowing water and the piping system (pipe, fittings, valves, etc).
GGPM - an abbreviation for "Gallons Per Minute;" the unit of measure for water flow.
Gear Drive Sprinkler - a sprinkler head that shoots water in a single or multiple streams and rotates to provide even coverage. Water flowing through the sprinkler spins a turbine connected to a series of gears that rotate the nozzle turret. Most gear drive sprinklers have adjustable spray patterns; however, some models have fixed spray patterns. Distance of throw is adjustable on almost all models and is usually 30-40' maximum radius.
HHead-to-Head Coverage - aka "Head-to-Head Spacing," this refers to the placement of sprinklers so that the end of each sprinkler's distance of throw reaches each adjacent sprinkler.
IIrrigation System - A set of components that work together to distribute water to lawns, landscaping, or other planting areas. Some of the components in an Irrigation System include: Backflow Prevention Device, Controller, Control Valve, Poly pipe OR PVC pipe, Sprinkler Head, Wire, Valve Box, etc.
Impact Sprinkler - a sprinkler head that shoots water in a single stream and rotates to provide even coverage.
LLine - slang term for a PVC or POLY pipe that is already installed in the ground.
MMain Line - the pipe in an irrigation system between the house water supply and the control valves. The Backflow Prevention Device is installed on this pipe immediately after the pipe exits the house. Generally, this pipe is under constant water pressure - Dynamic Water Pressure when the system is running, and Static Water Pressure when the system is idle.
Manifold - aka "Valve Manifold;" a group or set of control valves located together, usually in a valve box.
Master Valve - a control valve that is installed on, and controls water flow to, the main line. A master valve is usually installed immediately after the main line exits the house. Two options that are very common for master valves are: flow control and backflow prevention (atmospheric vacuum breaker).
PPoly Pipe - Short for Polyethylene pipe; a black, flexible pipe. Poly pipe is used in sprinkler systems installed in northern climates because of its flexibility which allows it to withstand harsh winters. Poly pipe sizes are measured by the Inside diameter of the pipe.
Potable Water - Water that is suitable for and used for drinking.
Pressure Vacuum Breaker (PVB) - a backflow prevention device that uses gravity to operate. This device must be mounted at least 12" higher than any sprinkler head or other outlet in the entire system.
PSI - an abbreviation for "Pounds per Square Inch;" the unit of measure for pressure.
PVC pipe - Poly Vinyl Chloride pipe; this is white, rigid pipe used in most non-Northern climate sprinkler systems. PVC pipe size is measured by the Outside diameter of the pipe.
RRadius - geometric term used to define the distance from the center of a circle to the edge of the circle in a straight line.
Reduced Pressure Device (RPZ) - a backflow prevention device that uses a double check assembly for maximum backflow protection. Because RPZ's do not use gravity to function, there are no mounting restrictions. Therefore this device can be mounted at or below grade.
SShut-off Valve - aka "Master shut-off Valve;" this is the component in the sprinkler system that allows you to manually turn off the water to the entire sprinkler system. In northern climates, this is used during the winterization process to turn off water to the sprinkler system for the winter without disrupting the water supply for the remainder of the house.
Spray Pattern - this is the area where a sprinkler sprays water. The Spray Pattern can be either adjustable or fixed (not adjustable) depending on the specific model of sprinkler head. Also see coverage.
Sprinkler Head - The component in a sprinkler system that sprays water and controls the discharge rate and coverage (spray pattern). Sprinkler Heads are classified into 3 major categories: Gear Drive Sprinklers, Fan Spray Sprinklers, and Impact Sprinklers.
Static Water Pressure - the pressure water exerts on a piping system when there is no water flow; measured in PSI. Static water pressure will always be higher than Dynamic water pressure.
TTimer - see controller.
VValve Box - a rectangular or circular box buried flush with the ground that is designed to protect a control valve or manifold while allowing access through the lid for servicing.
WWater Pressure - the force that water exerts on the piping system (pipe, fittings, valves, etc). Water pressure is measured in PSI.
ZZone - aka "Station," a group of sprinklers that are controlled by the same control valve and therefore operate together.
Zone Line - aka "Lateral Line," the pipe located downstream from the control valve that supplies water to the sprinklers. This pipe is only under water pressure when its respective zone is running. Therefore it only experiences Dynamic Water Pressure and never experiences Static Water Pressure.