Page 1 of 111
Irrigation Technician Certification Exam,
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Irrigation Technician Certification Exam,
Summarized Exam Topics Covered (Point Form – Accurate for Irrigation Technician Exam)
• Hydraulics: Pipe sizing, friction loss, pressure (static, dynamic, residual), flow (GPM), velocity (5
ft/s max for PVC), elevation head
• Pumps & Pumping Systems: Centrifugal pumps, pump curves, NPSH, priming, impeller types,
cavitation
• Backflow Prevention: Types (RP, DCVA, PVB, AVB), testing requirements, cross-connection
control, local codes
• Water Sources: Municipal, well, pond, lake, creek – filtration requirements, pump selection
• Sprinkler Types: Rotors, sprays (fixed spray, rotary nozzle), drip (emitters, tubing), bubblers
• Sprinkler Spacing: Head-to-head coverage (50-100% diameter overlap), square vs. triangular
spacing
• Nozzles: Flow rates, pressure regulation, trajectory, radius adjustment, precipitation rate
• Piping & Fittings: PVC (Schedule 40, Class 200), poly (polyethylene), solvent welding,
compression fittings, thrust blocking
• Valves: Automatic (solenoid, diaphragm), manual (gate, ball, globe), isolation valves, flow
control
• Controllers (Irrigation Timers): Programming (run times, start times, days, sensor inputs),
rain/freeze sensors, ET controllers, smart controllers
• Wiring & Low Voltage: 24 VAC solenoids, wire sizing (voltage drop), splices (waterproof),
common wire, master valves
• Maintenance & Troubleshooting: Leaks, low pressure, high pressure, non-operating valves,
short circuits, poor coverage
• Water Conservation: Precipitation rate matching, cycle & soak, rain shutoff devices, soil
moisture sensors, ET adjustment
• Soil & Plant Factors: Soil types (sand, loam, clay), infiltration rate, plant water requirements
(ET), root depth
• Electrical Testing: Multimeter (voltage, resistance, continuity), solenoid testing (20-60 ohms
typical), finding shorts
• Winterization: Compressed air blowout (max pressure 50-80 psi, 30-50 cfm), drain methods
• Safety: Trenching (shoring), electrical safety (wire locating), PPE, lockout/tagout
• Codes & Standards: Uniform Plumbing Code (UPC), local amendments, backflow prevention
requirements
• Rain Sensor / Freeze Sensor: Wiring (normally closed), bypass switch, automatic shutdown
• Pressure Regulation: Inline pressure regulators (drip systems), pressure-regulating sprinklers,
pressure loss calculation
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• Water Hammer: Causes (quick-closing valves), prevention (slow-closing valves, hammer
arrestors, check valves)
• Water Efficiency: Distribution uniformity (DU), scheduling coefficient (SC), precipitation rate
(PR)
1. A technician is installing a new irrigation zone. The sprinklers are spaced 40 ft apart in a square
pattern. The sprinkler radius is 25 ft at the operating pressure. Is this spacing acceptable?
A) Yes, 40 ft is less than 50 ft radius (head-to-head spacing)
B) No, the spacing exceeds 50% of the diameter (should be ≤ 50 ft between heads when radius is 25 ft?
25 ft radius = 50 ft diameter. Head-to-head spacing is 50 ft, so 40 ft is acceptable)
C) Yes, but only if the wind is low
D) No, the spacing must be 25 ft for square patterns
Answer: B
*Rationale: Head-to-head coverage requires spacing ≤ the sprinkler diameter (2 × radius). 25 ft radius =
50 ft diameter, so 40 ft spacing provides overlap (80% of diameter). Acceptable.*
2. A centrifugal pump delivers 50 GPM at 40 psi. The pump is cavitating. What is the most likely cause?
A) The pump is oversized for the system demand
B) The suction lift is too high or the suction line is restricted (low NPSH)
C) The discharge valve is fully open
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D) The impeller is too large
Answer: B
Rationale: Cavitation occurs when the pressure at the pump inlet drops below the vapor pressure of
water, causing bubbles to form and collapse. Causes include high suction lift, clogged strainer, or
restricted suction line.
3. A technician is installing a drip irrigation system for a vegetable garden. The mainline pressure is 60
psi, and the drip tubing is rated for 25 psi maximum. What device must be installed?
A) A backflow preventer
B) A pressure regulator (pressure-reducing valve) set to 25 psi
C) A check valve
D) A flow control valve
Answer: B
Rationale: Drip systems require pressure regulation to prevent tube rupture and emitter blow-out. A
pressure regulator reduces the 60 psi supply to the rated working pressure (25 psi).
4. A technician is testing an irrigation valve solenoid with a multimeter. The reading is 0 ohms. What
does this indicate?
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A) The solenoid is functioning normally (low resistance is good)
B) The solenoid coil is shorted (0 ohms indicates a short circuit)
C) The solenoid is open (infinite ohms)
D) The wiring is correct
Answer: B
Rationale: A typical irrigation solenoid coil resistance is 20-60 ohms. 0 ohms indicates a direct short
(shorted coil) or a short in the wiring.
5. What is the maximum recommended water velocity in a PVC pipe to prevent water hammer and
excessive friction loss?
A) 2 ft/s
B) 5 ft/s
C) 10 ft/s
D) 15 ft/s
Answer: B
*Rationale: Industry standard maximum velocity for PVC irrigation pipe is 5 ft/s to reduce friction loss
and prevent water hammer damage.*
Irrigation Technician Certification Exam,
QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Irrigation Technician Certification Exam,
Summarized Exam Topics Covered (Point Form – Accurate for Irrigation Technician Exam)
• Hydraulics: Pipe sizing, friction loss, pressure (static, dynamic, residual), flow (GPM), velocity (5
ft/s max for PVC), elevation head
• Pumps & Pumping Systems: Centrifugal pumps, pump curves, NPSH, priming, impeller types,
cavitation
• Backflow Prevention: Types (RP, DCVA, PVB, AVB), testing requirements, cross-connection
control, local codes
• Water Sources: Municipal, well, pond, lake, creek – filtration requirements, pump selection
• Sprinkler Types: Rotors, sprays (fixed spray, rotary nozzle), drip (emitters, tubing), bubblers
• Sprinkler Spacing: Head-to-head coverage (50-100% diameter overlap), square vs. triangular
spacing
• Nozzles: Flow rates, pressure regulation, trajectory, radius adjustment, precipitation rate
• Piping & Fittings: PVC (Schedule 40, Class 200), poly (polyethylene), solvent welding,
compression fittings, thrust blocking
• Valves: Automatic (solenoid, diaphragm), manual (gate, ball, globe), isolation valves, flow
control
• Controllers (Irrigation Timers): Programming (run times, start times, days, sensor inputs),
rain/freeze sensors, ET controllers, smart controllers
• Wiring & Low Voltage: 24 VAC solenoids, wire sizing (voltage drop), splices (waterproof),
common wire, master valves
• Maintenance & Troubleshooting: Leaks, low pressure, high pressure, non-operating valves,
short circuits, poor coverage
• Water Conservation: Precipitation rate matching, cycle & soak, rain shutoff devices, soil
moisture sensors, ET adjustment
• Soil & Plant Factors: Soil types (sand, loam, clay), infiltration rate, plant water requirements
(ET), root depth
• Electrical Testing: Multimeter (voltage, resistance, continuity), solenoid testing (20-60 ohms
typical), finding shorts
• Winterization: Compressed air blowout (max pressure 50-80 psi, 30-50 cfm), drain methods
• Safety: Trenching (shoring), electrical safety (wire locating), PPE, lockout/tagout
• Codes & Standards: Uniform Plumbing Code (UPC), local amendments, backflow prevention
requirements
• Rain Sensor / Freeze Sensor: Wiring (normally closed), bypass switch, automatic shutdown
• Pressure Regulation: Inline pressure regulators (drip systems), pressure-regulating sprinklers,
pressure loss calculation
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• Water Hammer: Causes (quick-closing valves), prevention (slow-closing valves, hammer
arrestors, check valves)
• Water Efficiency: Distribution uniformity (DU), scheduling coefficient (SC), precipitation rate
(PR)
1. A technician is installing a new irrigation zone. The sprinklers are spaced 40 ft apart in a square
pattern. The sprinkler radius is 25 ft at the operating pressure. Is this spacing acceptable?
A) Yes, 40 ft is less than 50 ft radius (head-to-head spacing)
B) No, the spacing exceeds 50% of the diameter (should be ≤ 50 ft between heads when radius is 25 ft?
25 ft radius = 50 ft diameter. Head-to-head spacing is 50 ft, so 40 ft is acceptable)
C) Yes, but only if the wind is low
D) No, the spacing must be 25 ft for square patterns
Answer: B
*Rationale: Head-to-head coverage requires spacing ≤ the sprinkler diameter (2 × radius). 25 ft radius =
50 ft diameter, so 40 ft spacing provides overlap (80% of diameter). Acceptable.*
2. A centrifugal pump delivers 50 GPM at 40 psi. The pump is cavitating. What is the most likely cause?
A) The pump is oversized for the system demand
B) The suction lift is too high or the suction line is restricted (low NPSH)
C) The discharge valve is fully open
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D) The impeller is too large
Answer: B
Rationale: Cavitation occurs when the pressure at the pump inlet drops below the vapor pressure of
water, causing bubbles to form and collapse. Causes include high suction lift, clogged strainer, or
restricted suction line.
3. A technician is installing a drip irrigation system for a vegetable garden. The mainline pressure is 60
psi, and the drip tubing is rated for 25 psi maximum. What device must be installed?
A) A backflow preventer
B) A pressure regulator (pressure-reducing valve) set to 25 psi
C) A check valve
D) A flow control valve
Answer: B
Rationale: Drip systems require pressure regulation to prevent tube rupture and emitter blow-out. A
pressure regulator reduces the 60 psi supply to the rated working pressure (25 psi).
4. A technician is testing an irrigation valve solenoid with a multimeter. The reading is 0 ohms. What
does this indicate?
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A) The solenoid is functioning normally (low resistance is good)
B) The solenoid coil is shorted (0 ohms indicates a short circuit)
C) The solenoid is open (infinite ohms)
D) The wiring is correct
Answer: B
Rationale: A typical irrigation solenoid coil resistance is 20-60 ohms. 0 ohms indicates a direct short
(shorted coil) or a short in the wiring.
5. What is the maximum recommended water velocity in a PVC pipe to prevent water hammer and
excessive friction loss?
A) 2 ft/s
B) 5 ft/s
C) 10 ft/s
D) 15 ft/s
Answer: B
*Rationale: Industry standard maximum velocity for PVC irrigation pipe is 5 ft/s to reduce friction loss
and prevent water hammer damage.*
