IRRIGATION VOCAB
Irrigation Technician - answer A person who works under the supervision of a licensed
irrigator to perform irrigation services including the connection of the irrigation system to
a private or public, raw or potable, water supply system or any water supply, and who is
required to be licensed.
Absorption Rate - answer The rate at which a soil will accept water. Rate decreases as
soil "capacity" is reached and is affected by soil type, slope, run-off, etc. It is also
referred to as "percolation rate" or "infiltration rate".
Actual Head Pressure (Dynamic Head Pressure) - answer Operating pressure at the
base of the sprinkler head. Calculated by subtracting all pressure losses, between the
head and the pressure source, from the static pressure at the source. It is also referred
to as "dynamic head pressure" or "working head pressure"
Air Gap - answerA complete physical separation between the free-flowing discharge
end of a potable water supply pipeline and an open or non-pressure receiving vessel.
Anti-Siphon Device - answerAny device that introduces air into the system to prevent
"back siphonage". See definitions for atmospheric vacuum breaker or pressure-type
vacuum breaker.
Application Rate (Precipitation Rate) - answerThe rate at which water is applied by the
irrigation system. It is usually measured in inches per hour. Often referred to as
precipitation rate: The following formulas are used to calculate precipitation rate:
GPM (full circle head) x 96.3 / Head Spacing x Row Spacing
or Total GPM x 96.3 / Total Area
Arc - answerThe surface area of the landscape to which the head will provide water.
Usually described in degrees or part of a circle. For example, a 90-degree arc would be
a quarter-circle sprinkler.
As-Built Plan - answerA 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. It is the final irrigation plan produced at the end of an installation. Also known as
"record drawings" or "as-builts"
Atmospheric Vacuum Breaker (AVB) - answerAn assembly containing an air inlet valve,
a check seat and an air inlet port. The flow of water into the body causes the air inlet
valve to close the air inlet port. When the flow of water stops the air inlet valves falls and
forms a check against back siphonage. At the same time, it opens the air inlet port
allowing air to enter and satisfy the vacuum. This device cannot be under constant
, pressure (more than 12 hours). It must be installed at least 6" higher than all
downstream piping and the highest downstream outlet. No back pressure may exist. No
shut off valves may be installed downstream of the AVB. This is NOT an approved
backflow prevention device to be used on irrigation systems in Texas.
Automatic Control Valve - answerAn electric 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 - answerAn irrigation system that will automatically cycle according to
a preset program
Backpressure - answerAny pressure, regardless of its source, against the outlet side of
the backflow prevention device, which exceeds the supply pressure against the inlet
side of the device. Examples: Pressure caused by gravity due to elevation differences; a
pump installed in the system; or steam and/or air pressure.
Back Siphonage - answerA form of backflow due to negative or sub-atmospheric
pressure within a potable water system.
Backflow - answerAn undesired reversal of the flow of water in a piping system. Caused
by backpressure or back siphonage.
Backflow Prevention. - answerThe mechanical prevention of reverse flow, or back
siphonage, of non-potable water from an irrigation system into the potable water source.
Backflow Prevention Assembly - answerAny assembly used to prevent backflow into a
potable water system. The type of assembly used is based on the hazard (health
hazard or non-health hazard) and hydraulic conditions.
Booster Pump - answerA pump that is installed on the water supply line and is designed
to raise the operating pressure in the irrigation system.
Bushing - answerA pipe fitting used to change to either a larger or smaller size
Check Valve - answerA valve that permits water to flow in one direction only.
Class Pipe - answerA method by which PVC pipe is grouped according to the working
pressure. Class 160; Class 200, Class 315 are examples of classes of pipe (Class 200
pipe can be used where pressures do not exceed 200 psi).
Commission - answerThe Texas Commission on Environmental Quality.
Consulting - answerThe act of providing advice, guidance review recommendations
related to landscape irrigation systems.
Irrigation Technician - answer A person who works under the supervision of a licensed
irrigator to perform irrigation services including the connection of the irrigation system to
a private or public, raw or potable, water supply system or any water supply, and who is
required to be licensed.
Absorption Rate - answer The rate at which a soil will accept water. Rate decreases as
soil "capacity" is reached and is affected by soil type, slope, run-off, etc. It is also
referred to as "percolation rate" or "infiltration rate".
Actual Head Pressure (Dynamic Head Pressure) - answer Operating pressure at the
base of the sprinkler head. Calculated by subtracting all pressure losses, between the
head and the pressure source, from the static pressure at the source. It is also referred
to as "dynamic head pressure" or "working head pressure"
Air Gap - answerA complete physical separation between the free-flowing discharge
end of a potable water supply pipeline and an open or non-pressure receiving vessel.
Anti-Siphon Device - answerAny device that introduces air into the system to prevent
"back siphonage". See definitions for atmospheric vacuum breaker or pressure-type
vacuum breaker.
Application Rate (Precipitation Rate) - answerThe rate at which water is applied by the
irrigation system. It is usually measured in inches per hour. Often referred to as
precipitation rate: The following formulas are used to calculate precipitation rate:
GPM (full circle head) x 96.3 / Head Spacing x Row Spacing
or Total GPM x 96.3 / Total Area
Arc - answerThe surface area of the landscape to which the head will provide water.
Usually described in degrees or part of a circle. For example, a 90-degree arc would be
a quarter-circle sprinkler.
As-Built Plan - answerA 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. It is the final irrigation plan produced at the end of an installation. Also known as
"record drawings" or "as-builts"
Atmospheric Vacuum Breaker (AVB) - answerAn assembly containing an air inlet valve,
a check seat and an air inlet port. The flow of water into the body causes the air inlet
valve to close the air inlet port. When the flow of water stops the air inlet valves falls and
forms a check against back siphonage. At the same time, it opens the air inlet port
allowing air to enter and satisfy the vacuum. This device cannot be under constant
, pressure (more than 12 hours). It must be installed at least 6" higher than all
downstream piping and the highest downstream outlet. No back pressure may exist. No
shut off valves may be installed downstream of the AVB. This is NOT an approved
backflow prevention device to be used on irrigation systems in Texas.
Automatic Control Valve - answerAn electric 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 - answerAn irrigation system that will automatically cycle according to
a preset program
Backpressure - answerAny pressure, regardless of its source, against the outlet side of
the backflow prevention device, which exceeds the supply pressure against the inlet
side of the device. Examples: Pressure caused by gravity due to elevation differences; a
pump installed in the system; or steam and/or air pressure.
Back Siphonage - answerA form of backflow due to negative or sub-atmospheric
pressure within a potable water system.
Backflow - answerAn undesired reversal of the flow of water in a piping system. Caused
by backpressure or back siphonage.
Backflow Prevention. - answerThe mechanical prevention of reverse flow, or back
siphonage, of non-potable water from an irrigation system into the potable water source.
Backflow Prevention Assembly - answerAny assembly used to prevent backflow into a
potable water system. The type of assembly used is based on the hazard (health
hazard or non-health hazard) and hydraulic conditions.
Booster Pump - answerA pump that is installed on the water supply line and is designed
to raise the operating pressure in the irrigation system.
Bushing - answerA pipe fitting used to change to either a larger or smaller size
Check Valve - answerA valve that permits water to flow in one direction only.
Class Pipe - answerA method by which PVC pipe is grouped according to the working
pressure. Class 160; Class 200, Class 315 are examples of classes of pipe (Class 200
pipe can be used where pressures do not exceed 200 psi).
Commission - answerThe Texas Commission on Environmental Quality.
Consulting - answerThe act of providing advice, guidance review recommendations
related to landscape irrigation systems.
