2025 LANDSCAPE IRRIGATION EXAM QUESTIONS WITH ANSWERS
2025/2026 GRADED A+
Gray water - Domestic wastewater composed of wash water from household sinks,
tubs, and washers.
Head to Head Spacing - Spacing of heads that is equal to the published radius.
Hydraulics - The study of fluid while in motion or at rest
Hydrozone - A portion of the landscaped area having plants with similar water needs
that are served by a valve or set of valves with the same schedule
Example: Naturalized area planted with native vegetation that will not need
supplemental irrigation once established is a non-irrigated hydrozone.
Impact Head - Type of rotary sprinkler head that utilizes a driver arm to create rotation.
Infiltration rate - The quantity of water that enters the soil surface in a specified time
interval. Often expressed in volume of water per unit of soil surface area per unit of
time.
Insert Fitting - A fitting which fits inside the pipe or tubing. Usually used on polyethylene
pipe and tubing.
IPS - Iron pipe size
Irrigation Design - A plan showing graphic or dimensional location of the components of
an irrigation system
Isolation valve - A gate or ball valve, serves as a main shut-off device for the complete
irrigation system as needed for servicing or repair. Must be located between the meter
and the backflow devices.
landscape irrigation - Art and management of applying water to the landscape in a
manner to encourage the growth of plant material and support water conservation.
Lateral Piping - Piping between the remote control valve, not subject to constant main
line pressure, and the sprinkler head.
Loop Main Line - A main line designed to provide water to any valve from two or more
directions. Generally improves hydraulics in larger landscapes.
Manifold - A group of two or more control valves together in one location and/or valve
box.
Master valve - Automatic or manual valve installed at the supply point which controls
water flow into the system main line piping.
, Matched precipitation (MPR) - All sprinkler heads within a watering zone will produce
similar precipitation rates, regardless of the pattern they cover.
MIP - Male iron pipe
MIPT - Male iron pipe thread
Non-potable water - Water not safe for drinking, personal, or culinary utilization.
Nozzle Tree - Interchangeable nozzle assortment, with different GPM and radii,
provided with many rotary heads
POC - Point of connection
Polyethylene Pipe (PE) - Flexible plastic pipe which uses insert fittings.
Potable water - water that is safe to drink
Precipitation rate - Precipitation rate (PR) is a calculation of the flow rate (application
rate) over the square footage of the zone. 96.25 = constant that converts gallons per
minute (GPM) to inches per hour.
Pressure compensating - A method of maintaining a constant discharge pressure
regardless of inlet pressure.
Pressure Regulator - Mechanical device that lowers water pressure on the downstream
side of the unit.
Pressure Vacuum Breaker - A backflow prevention assembly that incorporates a spring-
loaded check valve and introduces air into the system to prevent "back siphonage"
P.S.I. - Pounds per square inch
PVC pipe - Poly vinyl chloride pipe.
Quick Coupler Valve - A constantly pressurized valve set vertically in the ground to
provide supplemental water when a coupler key is inserted.
Radius - The distance from the center of a circle to any point on the circle
Reduced pressure principle device (RP,RPZ, or RPP) - Backflow prevention device that
consist of two independently acting check valves, together with an automatic operating
pressure differential relief valve located between the two check valves.
2025/2026 GRADED A+
Gray water - Domestic wastewater composed of wash water from household sinks,
tubs, and washers.
Head to Head Spacing - Spacing of heads that is equal to the published radius.
Hydraulics - The study of fluid while in motion or at rest
Hydrozone - A portion of the landscaped area having plants with similar water needs
that are served by a valve or set of valves with the same schedule
Example: Naturalized area planted with native vegetation that will not need
supplemental irrigation once established is a non-irrigated hydrozone.
Impact Head - Type of rotary sprinkler head that utilizes a driver arm to create rotation.
Infiltration rate - The quantity of water that enters the soil surface in a specified time
interval. Often expressed in volume of water per unit of soil surface area per unit of
time.
Insert Fitting - A fitting which fits inside the pipe or tubing. Usually used on polyethylene
pipe and tubing.
IPS - Iron pipe size
Irrigation Design - A plan showing graphic or dimensional location of the components of
an irrigation system
Isolation valve - A gate or ball valve, serves as a main shut-off device for the complete
irrigation system as needed for servicing or repair. Must be located between the meter
and the backflow devices.
landscape irrigation - Art and management of applying water to the landscape in a
manner to encourage the growth of plant material and support water conservation.
Lateral Piping - Piping between the remote control valve, not subject to constant main
line pressure, and the sprinkler head.
Loop Main Line - A main line designed to provide water to any valve from two or more
directions. Generally improves hydraulics in larger landscapes.
Manifold - A group of two or more control valves together in one location and/or valve
box.
Master valve - Automatic or manual valve installed at the supply point which controls
water flow into the system main line piping.
, Matched precipitation (MPR) - All sprinkler heads within a watering zone will produce
similar precipitation rates, regardless of the pattern they cover.
MIP - Male iron pipe
MIPT - Male iron pipe thread
Non-potable water - Water not safe for drinking, personal, or culinary utilization.
Nozzle Tree - Interchangeable nozzle assortment, with different GPM and radii,
provided with many rotary heads
POC - Point of connection
Polyethylene Pipe (PE) - Flexible plastic pipe which uses insert fittings.
Potable water - water that is safe to drink
Precipitation rate - Precipitation rate (PR) is a calculation of the flow rate (application
rate) over the square footage of the zone. 96.25 = constant that converts gallons per
minute (GPM) to inches per hour.
Pressure compensating - A method of maintaining a constant discharge pressure
regardless of inlet pressure.
Pressure Regulator - Mechanical device that lowers water pressure on the downstream
side of the unit.
Pressure Vacuum Breaker - A backflow prevention assembly that incorporates a spring-
loaded check valve and introduces air into the system to prevent "back siphonage"
P.S.I. - Pounds per square inch
PVC pipe - Poly vinyl chloride pipe.
Quick Coupler Valve - A constantly pressurized valve set vertically in the ground to
provide supplemental water when a coupler key is inserted.
Radius - The distance from the center of a circle to any point on the circle
Reduced pressure principle device (RP,RPZ, or RPP) - Backflow prevention device that
consist of two independently acting check valves, together with an automatic operating
pressure differential relief valve located between the two check valves.
