JOURNEYMAN PLUMBER LICENSING
EXAM QUESTION AND CORRECT
ANSWERS(VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A INSTANT
DOWNLOAD PDF
1. Which fitting is used to connect two pipes of different diameters?
A. Coupling
B. Union
C. Elbow
D. Tee
Answer: A
Rationale: A coupling, specifically a reducing coupling, is designed to join
pipes of different sizes in a straight line.
2. What is the minimum slope required for a 3-inch horizontal drainage pipe?
A. 1/8 inch per foot
B. 1/16 inch per foot
C. 1/4 inch per foot
D. Level
Answer: C
Rationale: Plumbing codes generally require a minimum slope of 1/4 inch
per foot for drainage pipes 3 inches or smaller.
3. What device prevents sewer gases from entering a building?
A. Vent
B. Trap
C. Cleanout
D. Backflow preventer
Answer: B
, Rationale: A trap holds water that creates a seal to block sewer gases
from entering occupied spaces.
4. Which pipe material is commonly used for potable water supply?
A. Cast iron
B. PVC Schedule 40
C. Copper
D. Clay
Answer: C
Rationale: Copper is widely approved and used for potable water due to
its durability and corrosion resistance.
5. What is the primary function of a vent stack?
A. Drain wastewater
B. Supply water
C. Equalize air pressure
D. Filter debris
Answer: C
Rationale: Vent stacks equalize pressure in the drainage system,
preventing trap siphonage.
6. A water hammer is caused by:
A. Low water pressure
B. Sudden valve closure
C. Pipe corrosion
D. Improper venting
Answer: B
Rationale: Water hammer results from a sudden stop in water flow,
creating shock waves in the piping.
7. Which fitting allows a pipe to change direction by 90 degrees?
A. Tee
B. Wye
C. Elbow
D. Coupling
Answer: C
, Rationale: Elbows are specifically designed to change the direction of
piping, commonly by 90 or 45 degrees.
8. What is the purpose of a cleanout?
A. Increase water pressure
B. Vent the system
C. Allow access for cleaning
D. Prevent backflow
Answer: C
Rationale: Cleanouts provide access points for removing blockages in
drainage systems.
9. Which valve is used to prevent backflow in potable water systems?
A. Gate valve
B. Check valve
C. Globe valve
D. Relief valve
Answer: B
Rationale: Check valves allow flow in one direction only, preventing
contamination from backflow.
10.What does DWV stand for in plumbing?
A. Drain Water Valve
B. Drain Waste Vent
C. Domestic Water Vent
D. Direct Water Volume
Answer: B
Rationale: DWV systems handle drainage, waste removal, and venting.
11.The main purpose of pipe insulation is to:
A. Increase pressure
B. Prevent leaks
C. Reduce heat loss
D. Improve flow
Answer: C
Rationale: Insulation minimizes heat transfer, protecting hot and cold
water lines.
EXAM QUESTION AND CORRECT
ANSWERS(VERIFIED ANSWERS) PLUS
RATIONALES 2026 Q&A INSTANT
DOWNLOAD PDF
1. Which fitting is used to connect two pipes of different diameters?
A. Coupling
B. Union
C. Elbow
D. Tee
Answer: A
Rationale: A coupling, specifically a reducing coupling, is designed to join
pipes of different sizes in a straight line.
2. What is the minimum slope required for a 3-inch horizontal drainage pipe?
A. 1/8 inch per foot
B. 1/16 inch per foot
C. 1/4 inch per foot
D. Level
Answer: C
Rationale: Plumbing codes generally require a minimum slope of 1/4 inch
per foot for drainage pipes 3 inches or smaller.
3. What device prevents sewer gases from entering a building?
A. Vent
B. Trap
C. Cleanout
D. Backflow preventer
Answer: B
, Rationale: A trap holds water that creates a seal to block sewer gases
from entering occupied spaces.
4. Which pipe material is commonly used for potable water supply?
A. Cast iron
B. PVC Schedule 40
C. Copper
D. Clay
Answer: C
Rationale: Copper is widely approved and used for potable water due to
its durability and corrosion resistance.
5. What is the primary function of a vent stack?
A. Drain wastewater
B. Supply water
C. Equalize air pressure
D. Filter debris
Answer: C
Rationale: Vent stacks equalize pressure in the drainage system,
preventing trap siphonage.
6. A water hammer is caused by:
A. Low water pressure
B. Sudden valve closure
C. Pipe corrosion
D. Improper venting
Answer: B
Rationale: Water hammer results from a sudden stop in water flow,
creating shock waves in the piping.
7. Which fitting allows a pipe to change direction by 90 degrees?
A. Tee
B. Wye
C. Elbow
D. Coupling
Answer: C
, Rationale: Elbows are specifically designed to change the direction of
piping, commonly by 90 or 45 degrees.
8. What is the purpose of a cleanout?
A. Increase water pressure
B. Vent the system
C. Allow access for cleaning
D. Prevent backflow
Answer: C
Rationale: Cleanouts provide access points for removing blockages in
drainage systems.
9. Which valve is used to prevent backflow in potable water systems?
A. Gate valve
B. Check valve
C. Globe valve
D. Relief valve
Answer: B
Rationale: Check valves allow flow in one direction only, preventing
contamination from backflow.
10.What does DWV stand for in plumbing?
A. Drain Water Valve
B. Drain Waste Vent
C. Domestic Water Vent
D. Direct Water Volume
Answer: B
Rationale: DWV systems handle drainage, waste removal, and venting.
11.The main purpose of pipe insulation is to:
A. Increase pressure
B. Prevent leaks
C. Reduce heat loss
D. Improve flow
Answer: C
Rationale: Insulation minimizes heat transfer, protecting hot and cold
water lines.
