Irrigation Technician Certification Exam
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download
Pdf
1. A residential irrigation system is supplied by a municipal water meter with a
static pressure of 65 PSI. After flowing 10 GPM through the service line, the
pressure at the backflow preventer drops to 58 PSI. What is the pressure loss
due to friction in the service line?
A) 3 PSI
B) 7 PSI
C) 13 PSI
D) 10 PSI
Answer: B) 7 PSI
Rationale: Friction loss is calculated as the difference between static pressure
(no flow) and residual pressure (under flow). 65 PSI static minus 58 PSI
residual equals 7 PSI loss. This loss is caused by the friction of water moving
through the pipe and fittings.
2. A technician measures water velocity in a 1-inch Class 200 PVC pipe at 8 feet
per second. Which problem is most likely to occur if this velocity is sustained
during normal operation?
A) Water hammer and potential pipe failure
B) Reduced pressure downstream due to laminar flow
C) Excessive precipitation rate uniformity
D) Improved nozzle performance
Answer: A) Water hammer and potential pipe failure
Rationale: The industry standard maximum safe velocity for PVC pipe is 5 feet
, per second. Velocities above 7.5 fps dramatically increase surge pressures
when valves close, causing water hammer that can rupture pipes or fittings.
3. What is the primary function of a check valve installed on a mainline
upstream of an electric valve manifold?
A) To regulate flow to each zone
B) To prevent low-head drainage and line hammer
C) To filter debris before the valves
D) To increase static pressure for the controller
Answer: B) To prevent low-head drainage and line hammer
Rationale: Check valves trap water in the mainline when valves close,
preventing the water column from draining out of the lowest heads and
avoiding the air intrusion that causes water hammer when the valve reopens.
4. When designing a sprinkler zone with rotor heads, matched precipitation
rate is achieved by:
A) Installing identical nozzles in all rotors regardless of arc
B) Using nozzles that apply water at the same rate across different arcs and
radii
C) Reducing the operating pressure to 25 PSI at each head
D) Installing a pressure-compensating screen at each rotor inlet
Answer: B) Using nozzles that apply water at the same rate across different
arcs and radii
Rationale: Matched precipitation means that a full-circle rotor and a quarter-
circle rotor on the same zone deliver the same inches per hour, preventing
dry or wet spots. This requires selecting nozzles with matched precipitation
rates (MPR) for their respective arcs.
5. An irrigation valve fails to close completely, allowing a small stream of water
to pass even when the solenoid is de-energized. The most likely cause is:
A) Incorrect controller programming
B) Debris trapped on the diaphragm seat or a damaged diaphragm
C) A blown fuse in the controller
D) Wire gauge too small for the solenoid
, Answer: B) Debris trapped on the diaphragm seat or a damaged diaphragm
Rationale: Constant weeping indicates the valve cannot achieve a tight seal.
A grain of sand on the seat, a torn diaphragm, or a stuck plunger in the
solenoid exhaust port prevents the upper chamber from pressurizing, keeping
the valve partially open.
6. A technician is using a multimeter to check resistance across a valve solenoid
that is not operating. The reading is “OL” (overload). What does this
indicate?
A) The solenoid coil has a short circuit
B) The solenoid coil is open or broken
C) The wire path has high capacitance
D) The controller output is under-voltage
Answer: B) The solenoid coil is open or broken
Rationale: An “OL” reading on resistance means infinite resistance, indicating
an open circuit—usually a broken coil wire or a severed solenoid. A normal
irrigation solenoid reads between 20 and 60 ohms.
7. Which type of backflow prevention device is generally approved for
high-hazard applications where irrigation water is injected with fertilizers or
chemicals?
A) Atmospheric vacuum breaker
B) Double check valve assembly
C) Reduced pressure principle assembly
D) Pressure vacuum breaker
Answer: C) Reduced pressure principle assembly
Rationale: An RPZ (reduced pressure zone) assembly provides the highest
level of protection, including against back-pressure and back-siphonage, and
is required when chemicals are introduced. It includes a relief valve that
opens if the differential pressure drops, indicating a potential contamination.
8. A landscape area has fine sandy loam soil with an infiltration rate of 1.0 inch
per hour. A spray head zone applies 1.8 inches per hour. What scheduling
adjustment is most appropriate to prevent runoff?
, A) Increase run time and reduce cycle frequency
B) Use cycle-and-soak scheduling with multiple short run times
C) Replace all spray heads with rotors maintaining the same precipitation
rate
D) Reduce operating pressure to lower the application rate below 1.0 in/hr
Answer: B) Use cycle-and-soak scheduling with multiple short run times
Rationale: The application rate exceeds the soil’s infiltration rate.
Cycle-and-soak breaks the total run time into shorter pulses separated by
soak periods, allowing water to infiltrate without runoff. Replacing heads
with rotors might lower PR, but cycle-and-soak directly addresses the rate
mismatch.
9. When trenching for mainline pipe, OSHA requires that a trench deeper than
5 feet must have:
A) Sloping, benching, or protective system in stable soil, or a registered
professional engineer design
B) A trench box only if the soil is Type C
C) Daily visual inspection only if the soil is dry
D) Warning tape placed at 12-inch depth
Answer: A) Sloping, benching, or protective system in stable soil, or a
registered professional engineer design
Rationale: Under OSHA excavation standards, any trench 5 feet or deeper
requires a protective system such as sloping, benching, shoring, or a trench
shield. A competent person must classify soil and determine the system.
10.A technician installs a new gear-driven rotor with a 3.0 GPM nozzle at 45 PSI.
The manufacturer’s chart shows a radius of 32 feet at that pressure. If the
head is spaced at 35 feet in a square layout, what is the approximate
head-to-head coverage percentage?
A) 91%
B) 100%
C) 109%
D) 80%
Answer: A) 91%
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant Download
1. A residential irrigation system is supplied by a municipal water meter with a
static pressure of 65 PSI. After flowing 10 GPM through the service line, the
pressure at the backflow preventer drops to 58 PSI. What is the pressure loss
due to friction in the service line?
A) 3 PSI
B) 7 PSI
C) 13 PSI
D) 10 PSI
Answer: B) 7 PSI
Rationale: Friction loss is calculated as the difference between static pressure
(no flow) and residual pressure (under flow). 65 PSI static minus 58 PSI
residual equals 7 PSI loss. This loss is caused by the friction of water moving
through the pipe and fittings.
2. A technician measures water velocity in a 1-inch Class 200 PVC pipe at 8 feet
per second. Which problem is most likely to occur if this velocity is sustained
during normal operation?
A) Water hammer and potential pipe failure
B) Reduced pressure downstream due to laminar flow
C) Excessive precipitation rate uniformity
D) Improved nozzle performance
Answer: A) Water hammer and potential pipe failure
Rationale: The industry standard maximum safe velocity for PVC pipe is 5 feet
, per second. Velocities above 7.5 fps dramatically increase surge pressures
when valves close, causing water hammer that can rupture pipes or fittings.
3. What is the primary function of a check valve installed on a mainline
upstream of an electric valve manifold?
A) To regulate flow to each zone
B) To prevent low-head drainage and line hammer
C) To filter debris before the valves
D) To increase static pressure for the controller
Answer: B) To prevent low-head drainage and line hammer
Rationale: Check valves trap water in the mainline when valves close,
preventing the water column from draining out of the lowest heads and
avoiding the air intrusion that causes water hammer when the valve reopens.
4. When designing a sprinkler zone with rotor heads, matched precipitation
rate is achieved by:
A) Installing identical nozzles in all rotors regardless of arc
B) Using nozzles that apply water at the same rate across different arcs and
radii
C) Reducing the operating pressure to 25 PSI at each head
D) Installing a pressure-compensating screen at each rotor inlet
Answer: B) Using nozzles that apply water at the same rate across different
arcs and radii
Rationale: Matched precipitation means that a full-circle rotor and a quarter-
circle rotor on the same zone deliver the same inches per hour, preventing
dry or wet spots. This requires selecting nozzles with matched precipitation
rates (MPR) for their respective arcs.
5. An irrigation valve fails to close completely, allowing a small stream of water
to pass even when the solenoid is de-energized. The most likely cause is:
A) Incorrect controller programming
B) Debris trapped on the diaphragm seat or a damaged diaphragm
C) A blown fuse in the controller
D) Wire gauge too small for the solenoid
, Answer: B) Debris trapped on the diaphragm seat or a damaged diaphragm
Rationale: Constant weeping indicates the valve cannot achieve a tight seal.
A grain of sand on the seat, a torn diaphragm, or a stuck plunger in the
solenoid exhaust port prevents the upper chamber from pressurizing, keeping
the valve partially open.
6. A technician is using a multimeter to check resistance across a valve solenoid
that is not operating. The reading is “OL” (overload). What does this
indicate?
A) The solenoid coil has a short circuit
B) The solenoid coil is open or broken
C) The wire path has high capacitance
D) The controller output is under-voltage
Answer: B) The solenoid coil is open or broken
Rationale: An “OL” reading on resistance means infinite resistance, indicating
an open circuit—usually a broken coil wire or a severed solenoid. A normal
irrigation solenoid reads between 20 and 60 ohms.
7. Which type of backflow prevention device is generally approved for
high-hazard applications where irrigation water is injected with fertilizers or
chemicals?
A) Atmospheric vacuum breaker
B) Double check valve assembly
C) Reduced pressure principle assembly
D) Pressure vacuum breaker
Answer: C) Reduced pressure principle assembly
Rationale: An RPZ (reduced pressure zone) assembly provides the highest
level of protection, including against back-pressure and back-siphonage, and
is required when chemicals are introduced. It includes a relief valve that
opens if the differential pressure drops, indicating a potential contamination.
8. A landscape area has fine sandy loam soil with an infiltration rate of 1.0 inch
per hour. A spray head zone applies 1.8 inches per hour. What scheduling
adjustment is most appropriate to prevent runoff?
, A) Increase run time and reduce cycle frequency
B) Use cycle-and-soak scheduling with multiple short run times
C) Replace all spray heads with rotors maintaining the same precipitation
rate
D) Reduce operating pressure to lower the application rate below 1.0 in/hr
Answer: B) Use cycle-and-soak scheduling with multiple short run times
Rationale: The application rate exceeds the soil’s infiltration rate.
Cycle-and-soak breaks the total run time into shorter pulses separated by
soak periods, allowing water to infiltrate without runoff. Replacing heads
with rotors might lower PR, but cycle-and-soak directly addresses the rate
mismatch.
9. When trenching for mainline pipe, OSHA requires that a trench deeper than
5 feet must have:
A) Sloping, benching, or protective system in stable soil, or a registered
professional engineer design
B) A trench box only if the soil is Type C
C) Daily visual inspection only if the soil is dry
D) Warning tape placed at 12-inch depth
Answer: A) Sloping, benching, or protective system in stable soil, or a
registered professional engineer design
Rationale: Under OSHA excavation standards, any trench 5 feet or deeper
requires a protective system such as sloping, benching, shoring, or a trench
shield. A competent person must classify soil and determine the system.
10.A technician installs a new gear-driven rotor with a 3.0 GPM nozzle at 45 PSI.
The manufacturer’s chart shows a radius of 32 feet at that pressure. If the
head is spaced at 35 feet in a square layout, what is the approximate
head-to-head coverage percentage?
A) 91%
B) 100%
C) 109%
D) 80%
Answer: A) 91%
