CT Unlimited Plumbing Journeyperson (P-
2) Exam Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of a plumbing trap?
A. To increase water pressure
B. To prevent water hammer
C. To prevent sewer gases from entering a building
D. To increase drainage velocity
Rationale: A plumbing trap retains a water seal that blocks sewer
gases from entering occupied spaces. The trap does not primarily
regulate pressure or increase drainage velocity.
2. Which fitting is commonly used to change the direction of a
drainage pipe while maintaining relatively smooth flow?
A. Sanitary tee
B. Long-sweep elbow
,C. Coupling
D. Reducing bushing
Rationale: A long-sweep elbow provides a gradual change in
direction, reducing turbulence and helping solids move through the
drainage system. Sharp directional changes are generally avoided in
drainage piping.
3. What is the minimum function of a venting system in a drainage
installation?
A. To supply potable water
B. To increase fixture water pressure
C. To protect trap seals and allow proper drainage-system airflow
D. To collect stormwater
Rationale: Drainage vents allow air into and out of the drainage
system, helping maintain atmospheric pressure and protecting trap
seals from siphonage or backpressure.
4. Which material is commonly used for potable water distribution
because of its corrosion resistance and durability?
A. Cast iron
B. Copper
,C. Unprotected steel
D. Clay
Rationale: Copper is widely used in potable water systems because it
is durable, corrosion resistant under normal conditions, and suitable
for hot and cold water distribution.
5. What does the term “DWV” stand for?
A. Domestic Water Valve
B. Drain Water Volume
C. Drain, Waste, and Vent
D. Distribution Water Vent
Rationale: DWV describes piping systems that carry wastewater and
provide ventilation for the drainage system. These systems are
separate in function from potable water distribution.
6. Which fitting should generally be used to connect a horizontal
branch drain to a horizontal drainage pipe?
A. Straight tee
B. Wye fitting
C. Reducing coupling
D. Cap
, Rationale: A wye provides a gradual entry into the drainage line and
is designed to promote smoother flow. A standard sanitary tee is
typically used in appropriate vertical-to-horizontal drainage
connections rather than horizontal-to-horizontal flow.
7. What is the purpose of a cleanout?
A. To regulate water temperature
B. To increase water pressure
C. To provide access for cleaning and clearing a drainage pipe
D. To prevent freezing
Rationale: Cleanouts provide accessible openings into drainage piping
so plumbers can inspect, snake, or otherwise clear blockages without
dismantling the piping system.
8. Which device is designed to prevent contaminated water from
reversing direction into the potable water supply?
A. Pressure-reducing valve
B. Backflow prevention device
C. Gate valve
D. Water hammer arrestor
2) Exam Questions and Correct Answers
(Verified Answers) Plus Rationale 2027
Q&A| Instant Download Pdf
1. What is the primary purpose of a plumbing trap?
A. To increase water pressure
B. To prevent water hammer
C. To prevent sewer gases from entering a building
D. To increase drainage velocity
Rationale: A plumbing trap retains a water seal that blocks sewer
gases from entering occupied spaces. The trap does not primarily
regulate pressure or increase drainage velocity.
2. Which fitting is commonly used to change the direction of a
drainage pipe while maintaining relatively smooth flow?
A. Sanitary tee
B. Long-sweep elbow
,C. Coupling
D. Reducing bushing
Rationale: A long-sweep elbow provides a gradual change in
direction, reducing turbulence and helping solids move through the
drainage system. Sharp directional changes are generally avoided in
drainage piping.
3. What is the minimum function of a venting system in a drainage
installation?
A. To supply potable water
B. To increase fixture water pressure
C. To protect trap seals and allow proper drainage-system airflow
D. To collect stormwater
Rationale: Drainage vents allow air into and out of the drainage
system, helping maintain atmospheric pressure and protecting trap
seals from siphonage or backpressure.
4. Which material is commonly used for potable water distribution
because of its corrosion resistance and durability?
A. Cast iron
B. Copper
,C. Unprotected steel
D. Clay
Rationale: Copper is widely used in potable water systems because it
is durable, corrosion resistant under normal conditions, and suitable
for hot and cold water distribution.
5. What does the term “DWV” stand for?
A. Domestic Water Valve
B. Drain Water Volume
C. Drain, Waste, and Vent
D. Distribution Water Vent
Rationale: DWV describes piping systems that carry wastewater and
provide ventilation for the drainage system. These systems are
separate in function from potable water distribution.
6. Which fitting should generally be used to connect a horizontal
branch drain to a horizontal drainage pipe?
A. Straight tee
B. Wye fitting
C. Reducing coupling
D. Cap
, Rationale: A wye provides a gradual entry into the drainage line and
is designed to promote smoother flow. A standard sanitary tee is
typically used in appropriate vertical-to-horizontal drainage
connections rather than horizontal-to-horizontal flow.
7. What is the purpose of a cleanout?
A. To regulate water temperature
B. To increase water pressure
C. To provide access for cleaning and clearing a drainage pipe
D. To prevent freezing
Rationale: Cleanouts provide accessible openings into drainage piping
so plumbers can inspect, snake, or otherwise clear blockages without
dismantling the piping system.
8. Which device is designed to prevent contaminated water from
reversing direction into the potable water supply?
A. Pressure-reducing valve
B. Backflow prevention device
C. Gate valve
D. Water hammer arrestor
