Irrigation Terms Exam Questions and
Answers
ABSORPTION RATE - Correct Answers -The rate at which a soil will accept water. Rate
decreases as soil "capacity" is reached. (Also called percolation rate).
ACTUAL HEAD PRESSURE - Correct Answers -Operating pressure at the base of the
sprinkler head. Calculated by subtracting all pressure losses from the static pressure.
AIR GAP - Correct Answers -A complete physical separation between the free flowing
discharge end of a potable water supply pipeline and an open or non-pressure receiving
vessel.
WATER SCHEDULING - Correct Answers -The procedure of establishing and
implementing the time, frequency, and amount of irrigation water to apply to landscape.
WATER WINDOW - Correct Answers -The allotted time available for operating an
irrigation system in a 24-hour period
ZONE FLOW - Correct Answers -A measurement, in gallons per minute or gallons per
hour, of the actual flow of water through a zone valve, calculated by individually opening
each zone valve and obtaining a valid reading after the pressure has stabilized. For
design purposes, the zone flow is the total flow of all nozzles in the zone at a specific
pressure.
ANTI-SIPHON DEVICE - Correct Answers -Any device that introduces air into the
system to prevent "back siphonage". See definitions for atmospheric vacuum breaker or
pressure-type vacuum breaker below.
APPLICATION RATE - Correct Answers -Rate at which water is applied by the irrigation
system. It is usually measured in inches per hour or gallons per hour. See
PRECIPITATION RATE
ARC - Correct Answers -The surface area of the landscape that the head will provide
water. Usually described in degrees or part of a circle, such as, a 90-degree arc would
be a quarter circle sprinkler.
, AS BUILT PLAN - Correct Answers -A corrected or redrawn plan (to scale) showing the
actual location of all major components of the system and other information the property
owner might require. See definition for "record drawing".
ATMOSPHERIC VACUUM BREAKER (AVB) - Correct Answers -A backflow prevention
device that introduces air into the piping system to prevent back siphonage. No
backpressure can exist. This device cannot be under constant pressure (constant
pressure is defined as "more than 12 hours".) It must be installed at least 6" higher than
all down stream piping and the highest downstream outlet. No shut off valves may exist
down stream of the AVB.
AUTOMATIC CONTROL VALVE - Correct Answers -An electric or hydraulic remote
control valve in a sprinkler system that is activated by an automatic controller. Also
called a section valve, zone valve, or remote control valve.
AUTOMATIC SYSTEM - Correct Answers -An irrigation system that will automatically
cycle (water) according to a preset program.
AWWA - Correct Answers -Abbreviation for American Water Works Association.
BACK PRESSURE - Correct Answers -Any condition that could create pressure in the
downstream piping system that is greater than in the upstream system. Examples:
Pressure caused by gravity due to elevation differences; a pump installed in the system;
or steam and/or air pressure.
BACK SIPHONAGE - Correct Answers -A form of backflow due to a negative or sub-
atmospheric pressure within a water system.
BACKFLOW - Correct Answers -Reverse flow of water in a piping system.
BACKFLOW PREVENTION - Correct Answers -The mechanical prevention of reverse
flow, or back siphonage, of nonpotable water from an irrigation system into the potable
water source.
BACKFLOW PREVENTION DEVICE - Correct Answers -Any approved device that
prevents an undesirable reversal of flow of water.
BACKFLOW PREVENTION ASSEMBLY - Correct Answers -Any assembly used to
prevent backflow into a potable water system. The type of assembly used is based on
the existing or potential degree of health hazard and backflow condition.
BOOSTER PUMP - Correct Answers -A pump that is installed in the water supply line
and is designed to raise the operating pressure in the irrigation system.
BUSHING - Correct Answers -The method of adapting a fitting to either a larger or
smaller size.
Answers
ABSORPTION RATE - Correct Answers -The rate at which a soil will accept water. Rate
decreases as soil "capacity" is reached. (Also called percolation rate).
ACTUAL HEAD PRESSURE - Correct Answers -Operating pressure at the base of the
sprinkler head. Calculated by subtracting all pressure losses from the static pressure.
AIR GAP - Correct Answers -A complete physical separation between the free flowing
discharge end of a potable water supply pipeline and an open or non-pressure receiving
vessel.
WATER SCHEDULING - Correct Answers -The procedure of establishing and
implementing the time, frequency, and amount of irrigation water to apply to landscape.
WATER WINDOW - Correct Answers -The allotted time available for operating an
irrigation system in a 24-hour period
ZONE FLOW - Correct Answers -A measurement, in gallons per minute or gallons per
hour, of the actual flow of water through a zone valve, calculated by individually opening
each zone valve and obtaining a valid reading after the pressure has stabilized. For
design purposes, the zone flow is the total flow of all nozzles in the zone at a specific
pressure.
ANTI-SIPHON DEVICE - Correct Answers -Any device that introduces air into the
system to prevent "back siphonage". See definitions for atmospheric vacuum breaker or
pressure-type vacuum breaker below.
APPLICATION RATE - Correct Answers -Rate at which water is applied by the irrigation
system. It is usually measured in inches per hour or gallons per hour. See
PRECIPITATION RATE
ARC - Correct Answers -The surface area of the landscape that the head will provide
water. Usually described in degrees or part of a circle, such as, a 90-degree arc would
be a quarter circle sprinkler.
, AS BUILT PLAN - Correct Answers -A corrected or redrawn plan (to scale) showing the
actual location of all major components of the system and other information the property
owner might require. See definition for "record drawing".
ATMOSPHERIC VACUUM BREAKER (AVB) - Correct Answers -A backflow prevention
device that introduces air into the piping system to prevent back siphonage. No
backpressure can exist. This device cannot be under constant pressure (constant
pressure is defined as "more than 12 hours".) It must be installed at least 6" higher than
all down stream piping and the highest downstream outlet. No shut off valves may exist
down stream of the AVB.
AUTOMATIC CONTROL VALVE - Correct Answers -An electric or hydraulic remote
control valve in a sprinkler system that is activated by an automatic controller. Also
called a section valve, zone valve, or remote control valve.
AUTOMATIC SYSTEM - Correct Answers -An irrigation system that will automatically
cycle (water) according to a preset program.
AWWA - Correct Answers -Abbreviation for American Water Works Association.
BACK PRESSURE - Correct Answers -Any condition that could create pressure in the
downstream piping system that is greater than in the upstream system. Examples:
Pressure caused by gravity due to elevation differences; a pump installed in the system;
or steam and/or air pressure.
BACK SIPHONAGE - Correct Answers -A form of backflow due to a negative or sub-
atmospheric pressure within a water system.
BACKFLOW - Correct Answers -Reverse flow of water in a piping system.
BACKFLOW PREVENTION - Correct Answers -The mechanical prevention of reverse
flow, or back siphonage, of nonpotable water from an irrigation system into the potable
water source.
BACKFLOW PREVENTION DEVICE - Correct Answers -Any approved device that
prevents an undesirable reversal of flow of water.
BACKFLOW PREVENTION ASSEMBLY - Correct Answers -Any assembly used to
prevent backflow into a potable water system. The type of assembly used is based on
the existing or potential degree of health hazard and backflow condition.
BOOSTER PUMP - Correct Answers -A pump that is installed in the water supply line
and is designed to raise the operating pressure in the irrigation system.
BUSHING - Correct Answers -The method of adapting a fitting to either a larger or
smaller size.
