AR PI Pump Installer Contractor Exam
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary function of a pump in a water system?
A. To eliminate all dissolved minerals from water
B. To transfer energy to a liquid so that it can move through a system
C. To prevent all water pressure fluctuations
D. To remove all suspended solids from water
Rationale: A pump converts mechanical energy into hydraulic energy,
allowing liquid to move through piping and overcome elevation
differences, friction losses, and system pressure requirements. Pumps
do not inherently remove dissolved minerals or all suspended solids.
2. Which pump type is most commonly used for residential water wells
with a submerged pump assembly?
,A. External gear pump
B. Horizontal split-case pump
C. Submersible centrifugal pump
D. Air-operated diaphragm pump
Rationale: A submersible centrifugal pump is designed to operate while
submerged in the water. It pushes water upward through the discharge
piping and is commonly used in deep residential wells. Its submerged
motor and pump assembly avoid the priming requirements associated
with many surface-mounted suction pumps.
3. What is the primary purpose of a pump impeller?
A. To measure water temperature
B. To impart energy to the liquid
C. To prevent electrical overloads
D. To regulate the water's chemical composition
Rationale: The impeller is the rotating component that transfers
mechanical energy to the liquid. In a centrifugal pump, it increases the
liquid's velocity, and the pump casing helps convert that velocity into
pressure. Impeller design influences flow, head, efficiency, and the type
of liquid the pump can handle.
,4. What does pump head represent?
A. The physical height of the pump casing
B. The diameter of the discharge pipe
C. The energy imparted to the liquid expressed as an equivalent
height of liquid
D. The total weight of the pump assembly
Rationale: Pump head expresses energy per unit weight of liquid as a
height of fluid column. It is commonly measured in feet or meters and
allows pump performance to be compared across different liquids. Total
dynamic head includes elevation, pressure, and friction-related
requirements.
5. Which condition is most likely to cause cavitation in a centrifugal
pump?
A. Excessive motor insulation resistance
B. A discharge pipe with adequate diameter
C. Insufficient pressure at the pump suction
D. A properly aligned motor shaft
Rationale: Cavitation occurs when local liquid pressure falls below the
liquid's vapor pressure, allowing vapor bubbles to form and
, subsequently collapse. Insufficient suction pressure, excessive suction
lift, high liquid temperature, or excessive flow can contribute. Cavitation
can cause noise, vibration, reduced performance, and impeller damage.
6. What is the purpose of a check valve installed in a pump discharge
line?
A. To increase the motor's horsepower
B. To remove sediment from the water
C. To prevent reverse flow when the pump stops
D. To measure the water's electrical conductivity
Rationale: A check valve allows flow in one direction and closes when
flow reverses. It helps prevent backflow through the pump and may
reduce reverse rotation and water hammer, depending on system
design. The valve must be selected and installed according to the
intended flow direction and operating conditions.
7. What is the primary purpose of a pressure tank in a typical
residential well-water system?
A. To increase the well's physical depth
B. To store pressurized water and reduce pump cycling
C. To remove all bacteria from the water
Questions and Correct Answers (Verified
Answers) Plus Rationale 2027 Q&A|
Instant Download Pdf
1. What is the primary function of a pump in a water system?
A. To eliminate all dissolved minerals from water
B. To transfer energy to a liquid so that it can move through a system
C. To prevent all water pressure fluctuations
D. To remove all suspended solids from water
Rationale: A pump converts mechanical energy into hydraulic energy,
allowing liquid to move through piping and overcome elevation
differences, friction losses, and system pressure requirements. Pumps
do not inherently remove dissolved minerals or all suspended solids.
2. Which pump type is most commonly used for residential water wells
with a submerged pump assembly?
,A. External gear pump
B. Horizontal split-case pump
C. Submersible centrifugal pump
D. Air-operated diaphragm pump
Rationale: A submersible centrifugal pump is designed to operate while
submerged in the water. It pushes water upward through the discharge
piping and is commonly used in deep residential wells. Its submerged
motor and pump assembly avoid the priming requirements associated
with many surface-mounted suction pumps.
3. What is the primary purpose of a pump impeller?
A. To measure water temperature
B. To impart energy to the liquid
C. To prevent electrical overloads
D. To regulate the water's chemical composition
Rationale: The impeller is the rotating component that transfers
mechanical energy to the liquid. In a centrifugal pump, it increases the
liquid's velocity, and the pump casing helps convert that velocity into
pressure. Impeller design influences flow, head, efficiency, and the type
of liquid the pump can handle.
,4. What does pump head represent?
A. The physical height of the pump casing
B. The diameter of the discharge pipe
C. The energy imparted to the liquid expressed as an equivalent
height of liquid
D. The total weight of the pump assembly
Rationale: Pump head expresses energy per unit weight of liquid as a
height of fluid column. It is commonly measured in feet or meters and
allows pump performance to be compared across different liquids. Total
dynamic head includes elevation, pressure, and friction-related
requirements.
5. Which condition is most likely to cause cavitation in a centrifugal
pump?
A. Excessive motor insulation resistance
B. A discharge pipe with adequate diameter
C. Insufficient pressure at the pump suction
D. A properly aligned motor shaft
Rationale: Cavitation occurs when local liquid pressure falls below the
liquid's vapor pressure, allowing vapor bubbles to form and
, subsequently collapse. Insufficient suction pressure, excessive suction
lift, high liquid temperature, or excessive flow can contribute. Cavitation
can cause noise, vibration, reduced performance, and impeller damage.
6. What is the purpose of a check valve installed in a pump discharge
line?
A. To increase the motor's horsepower
B. To remove sediment from the water
C. To prevent reverse flow when the pump stops
D. To measure the water's electrical conductivity
Rationale: A check valve allows flow in one direction and closes when
flow reverses. It helps prevent backflow through the pump and may
reduce reverse rotation and water hammer, depending on system
design. The valve must be selected and installed according to the
intended flow direction and operating conditions.
7. What is the primary purpose of a pressure tank in a typical
residential well-water system?
A. To increase the well's physical depth
B. To store pressurized water and reduce pump cycling
C. To remove all bacteria from the water
