Texas Landscape Irrigation 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 (dynamic head pressure) - Correct Answers -operating pressure
at the base of sprinkler head. Calculated by subtracting all pressure losses, between
head and pressure source.
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.
triangular head spacing - Correct Answers -Head Spacing * .866 =
row spacing
valve in head - Correct Answers -indicates that the automatic control valve is part of the
sprinkler
velocity (of water) - Correct Answers -speed at which water passes through piping
water hammer - Correct Answers -The surge in pressure when a high-velocity flow of
water is abruptly shut off. The pressure exerted by the flowing water against a closed
system can be seven or more times that of the static pressure
anti-siphon device - Correct Answers -Any device that introduces air into the system to
prevent "back siphonage".
application rate (precipitation rate) - Correct Answers -Rate at which water is applied by
sprinkler heads in a certain pattern. Measured in inches per hour.
Calculating precipitation rate - Correct Answers -GPM (full circle head) x 96.3
Head spacing x row spacing
or
GPM x 96.3
, Total Area
Arc - Correct Answers -the surface area of the landscape to which the head will provide
water. described in degrees or part of a circle.
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.
Atmospheric Vacuum Breaker - Correct Answers -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.
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 -irrigation system which will automatically cycle
according to a preset program.
back pressure - Correct Answers -any 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.
Back siphonage - Correct Answers -a form of backflow due to negative or sub-
atmospheric pressure within a potable water system
backflow - Correct Answers -The unwanted reverse flow of liquids in a piping system.
Caused by back pressure or back siphonage
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 assembly - Correct Answers -a pump that is installed on the water
supply line and is designed to raise the operating pressure in the irrigation system.
bushing - Correct Answers -A pipe fitting which is threaded on both the inside and the
outside so that it can be used to connect two pipes (or other fittings) of different sizes.
check valve - Correct Answers -Automatic valve that permits liquid flow in only one
direction.
class pipe - Correct Answers -the texas commission on environmental quality
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 (dynamic head pressure) - Correct Answers -operating pressure
at the base of sprinkler head. Calculated by subtracting all pressure losses, between
head and pressure source.
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.
triangular head spacing - Correct Answers -Head Spacing * .866 =
row spacing
valve in head - Correct Answers -indicates that the automatic control valve is part of the
sprinkler
velocity (of water) - Correct Answers -speed at which water passes through piping
water hammer - Correct Answers -The surge in pressure when a high-velocity flow of
water is abruptly shut off. The pressure exerted by the flowing water against a closed
system can be seven or more times that of the static pressure
anti-siphon device - Correct Answers -Any device that introduces air into the system to
prevent "back siphonage".
application rate (precipitation rate) - Correct Answers -Rate at which water is applied by
sprinkler heads in a certain pattern. Measured in inches per hour.
Calculating precipitation rate - Correct Answers -GPM (full circle head) x 96.3
Head spacing x row spacing
or
GPM x 96.3
, Total Area
Arc - Correct Answers -the surface area of the landscape to which the head will provide
water. described in degrees or part of a circle.
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.
Atmospheric Vacuum Breaker - Correct Answers -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.
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 -irrigation system which will automatically cycle
according to a preset program.
back pressure - Correct Answers -any 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.
Back siphonage - Correct Answers -a form of backflow due to negative or sub-
atmospheric pressure within a potable water system
backflow - Correct Answers -The unwanted reverse flow of liquids in a piping system.
Caused by back pressure or back siphonage
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 assembly - Correct Answers -a pump that is installed on the water
supply line and is designed to raise the operating pressure in the irrigation system.
bushing - Correct Answers -A pipe fitting which is threaded on both the inside and the
outside so that it can be used to connect two pipes (or other fittings) of different sizes.
check valve - Correct Answers -Automatic valve that permits liquid flow in only one
direction.
class pipe - Correct Answers -the texas commission on environmental quality
