COLORADO MASTER PLUMBER EXAM QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)
Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering a building
C. Increase drainage velocity
D. Filter potable water
Correct Answer: B. Prevent sewer gases from entering a building
Rationale: A trap maintains a water seal that blocks sewer gases
from entering occupied spaces.
2. Which fitting is commonly used to change the direction of a
drainage pipe by 90 degrees?
A. Coupling
B. Reducer
C. Elbow
D. Union
Correct Answer: C. Elbow
Rationale: An elbow changes the direction of piping, commonly
by 45 or 90 degrees.
3. What is the main purpose of a plumbing vent system?
A. Supply hot water
B. Maintain proper drainage system air pressure
,C. Increase water temperature
D. Store wastewater
Correct Answer: B. Maintain proper drainage system air
pressure
Rationale: Venting protects trap seals and allows drainage
systems to operate properly.
4. Which pipe material is commonly used for sanitary drainage
because of its corrosion resistance and light weight?
A. PVC
B. Cast iron only
C. Lead
D. Aluminum
Correct Answer: A. PVC
Rationale: PVC is widely used for drainage, waste, and vent
applications because it is lightweight and corrosion resistant.
5. What does DWV stand for?
A. Drain, Water, Valve
B. Drain, Waste, Vent
C. Domestic Water Vent
D. Drainage Water Volume
Correct Answer: B. Drain, Waste, Vent
Rationale: DWV systems carry wastewater and provide
ventilation for drainage piping.
6. What is the purpose of a cleanout?
A. Regulate water temperature
,B. Provide access for cleaning drainage piping
C. Prevent water hammer
D. Increase pipe pressure
Correct Answer: B. Provide access for cleaning drainage piping
Rationale: Cleanouts allow maintenance equipment to access
drainage piping.
7. Which device prevents contaminated water from flowing
backward into the potable water supply?
A. Pressure gauge
B. Backflow prevention device
C. Water heater
D. Expansion tank
Correct Answer: B. Backflow prevention device
Rationale: Backflow prevention devices protect potable water
from contamination.
8. What is water hammer?
A. Water contamination
B. A pressure surge caused by sudden changes in water flow
C. Low water pressure
D. Pipe corrosion
Correct Answer: B. A pressure surge caused by sudden changes
in water flow
Rationale: Rapidly closing a valve can create a pressure shock
known as water hammer.
, 9. What is the primary purpose of a water heater
temperature-and-pressure relief valve?
A. Increase water pressure
B. Prevent excessive temperature or pressure buildup
C. Reduce water consumption
D. Filter sediment
Correct Answer: B. Prevent excessive temperature or pressure
buildup
Rationale: The relief valve provides protection against
dangerous pressure or temperature conditions.
10. Which fitting is used to connect two pipes of different
diameters?
A. Tee
B. Coupling
C. Reducer
D. Cap
Correct Answer: C. Reducer
Rationale: A reducer transitions between different pipe sizes.
11. What is the purpose of a sanitary tee in a drainage
system?
A. Connect a horizontal drain to a vertical drain or vent
appropriately
B. Increase water pressure
C. Close a pipe
D. Measure flow
AND CORRECT ANSWERS (VERIFIED ANSWERS)
Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering a building
C. Increase drainage velocity
D. Filter potable water
Correct Answer: B. Prevent sewer gases from entering a building
Rationale: A trap maintains a water seal that blocks sewer gases
from entering occupied spaces.
2. Which fitting is commonly used to change the direction of a
drainage pipe by 90 degrees?
A. Coupling
B. Reducer
C. Elbow
D. Union
Correct Answer: C. Elbow
Rationale: An elbow changes the direction of piping, commonly
by 45 or 90 degrees.
3. What is the main purpose of a plumbing vent system?
A. Supply hot water
B. Maintain proper drainage system air pressure
,C. Increase water temperature
D. Store wastewater
Correct Answer: B. Maintain proper drainage system air
pressure
Rationale: Venting protects trap seals and allows drainage
systems to operate properly.
4. Which pipe material is commonly used for sanitary drainage
because of its corrosion resistance and light weight?
A. PVC
B. Cast iron only
C. Lead
D. Aluminum
Correct Answer: A. PVC
Rationale: PVC is widely used for drainage, waste, and vent
applications because it is lightweight and corrosion resistant.
5. What does DWV stand for?
A. Drain, Water, Valve
B. Drain, Waste, Vent
C. Domestic Water Vent
D. Drainage Water Volume
Correct Answer: B. Drain, Waste, Vent
Rationale: DWV systems carry wastewater and provide
ventilation for drainage piping.
6. What is the purpose of a cleanout?
A. Regulate water temperature
,B. Provide access for cleaning drainage piping
C. Prevent water hammer
D. Increase pipe pressure
Correct Answer: B. Provide access for cleaning drainage piping
Rationale: Cleanouts allow maintenance equipment to access
drainage piping.
7. Which device prevents contaminated water from flowing
backward into the potable water supply?
A. Pressure gauge
B. Backflow prevention device
C. Water heater
D. Expansion tank
Correct Answer: B. Backflow prevention device
Rationale: Backflow prevention devices protect potable water
from contamination.
8. What is water hammer?
A. Water contamination
B. A pressure surge caused by sudden changes in water flow
C. Low water pressure
D. Pipe corrosion
Correct Answer: B. A pressure surge caused by sudden changes
in water flow
Rationale: Rapidly closing a valve can create a pressure shock
known as water hammer.
, 9. What is the primary purpose of a water heater
temperature-and-pressure relief valve?
A. Increase water pressure
B. Prevent excessive temperature or pressure buildup
C. Reduce water consumption
D. Filter sediment
Correct Answer: B. Prevent excessive temperature or pressure
buildup
Rationale: The relief valve provides protection against
dangerous pressure or temperature conditions.
10. Which fitting is used to connect two pipes of different
diameters?
A. Tee
B. Coupling
C. Reducer
D. Cap
Correct Answer: C. Reducer
Rationale: A reducer transitions between different pipe sizes.
11. What is the purpose of a sanitary tee in a drainage
system?
A. Connect a horizontal drain to a vertical drain or vent
appropriately
B. Increase water pressure
C. Close a pipe
D. Measure flow
