Journeyman Plumber Licensing Exam
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
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1. A building drain is defined as:
A. Pipe inside wall
B. Pipe from trap to sewer
C. Pipe that carries rainwater only
D. Fixture connection only
Correct Answer: B
Rationale: The building drain carries wastewater from inside the building
to the building sewer or point of disposal.
2. The minimum slope for a 3-inch horizontal drain is typically:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: A
Rationale: Smaller pipes require at least 1/8 inch per foot to maintain
proper flow velocity.
,3. A P-trap is designed to:
A. Increase water pressure
B. Prevent sewer gas entry
C. Increase flow rate
D. Filter solids
Correct Answer: B
Rationale: The trap seal blocks sewer gases from entering the building.
4. Vent piping is required to:
A. Increase water pressure
B. Prevent siphonage of traps
C. Drain roof water
D. Carry waste to sewer
Correct Answer: B
Rationale: Vent systems maintain atmospheric pressure to protect trap
seals.
5. The main purpose of a cleanout is:
A. Increase flow
B. Provide access for clearing blockages
C. Support pipe
D. Measure pressure
Correct Answer: B
Rationale: Cleanouts allow maintenance access to remove obstructions in
piping systems.
6. Copper tubing is commonly joined using:
A. Glue
B. Welding only
C. Soldering or brazing
D. Rivets
Correct Answer: C
Rationale: Copper is joined using heat-based methods like soldering or
brazing.
, 7. A water hammer arrestor is used to:
A. Increase pressure
B. Stop pipe corrosion
C. Absorb shock from sudden water stop
D. Filter sediment
Correct Answer: C
Rationale: It absorbs pressure surges caused by fast-closing valves.
8. The standard test for DWV systems is:
A. Air or water test
B. Electrical test
C. Chemical test
D. Gas test only
Correct Answer: A
Rationale: Drain-waste-vent systems are tested using air or water
pressure tests.
9. PVC pipe is joined using:
A. Heat fusion
B. Solvent cement
C. Threading
D. Welding
Correct Answer: B
Rationale: PVC joints are chemically fused using solvent cement.
10.Backflow prevention devices are installed to:
A. Increase pressure
B. Prevent reverse flow contamination
C. Drain faster
D. Reduce pipe size
Correct Answer: B
Rationale: They prevent contaminated water from entering clean water
supply.
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
1. A building drain is defined as:
A. Pipe inside wall
B. Pipe from trap to sewer
C. Pipe that carries rainwater only
D. Fixture connection only
Correct Answer: B
Rationale: The building drain carries wastewater from inside the building
to the building sewer or point of disposal.
2. The minimum slope for a 3-inch horizontal drain is typically:
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: A
Rationale: Smaller pipes require at least 1/8 inch per foot to maintain
proper flow velocity.
,3. A P-trap is designed to:
A. Increase water pressure
B. Prevent sewer gas entry
C. Increase flow rate
D. Filter solids
Correct Answer: B
Rationale: The trap seal blocks sewer gases from entering the building.
4. Vent piping is required to:
A. Increase water pressure
B. Prevent siphonage of traps
C. Drain roof water
D. Carry waste to sewer
Correct Answer: B
Rationale: Vent systems maintain atmospheric pressure to protect trap
seals.
5. The main purpose of a cleanout is:
A. Increase flow
B. Provide access for clearing blockages
C. Support pipe
D. Measure pressure
Correct Answer: B
Rationale: Cleanouts allow maintenance access to remove obstructions in
piping systems.
6. Copper tubing is commonly joined using:
A. Glue
B. Welding only
C. Soldering or brazing
D. Rivets
Correct Answer: C
Rationale: Copper is joined using heat-based methods like soldering or
brazing.
, 7. A water hammer arrestor is used to:
A. Increase pressure
B. Stop pipe corrosion
C. Absorb shock from sudden water stop
D. Filter sediment
Correct Answer: C
Rationale: It absorbs pressure surges caused by fast-closing valves.
8. The standard test for DWV systems is:
A. Air or water test
B. Electrical test
C. Chemical test
D. Gas test only
Correct Answer: A
Rationale: Drain-waste-vent systems are tested using air or water
pressure tests.
9. PVC pipe is joined using:
A. Heat fusion
B. Solvent cement
C. Threading
D. Welding
Correct Answer: B
Rationale: PVC joints are chemically fused using solvent cement.
10.Backflow prevention devices are installed to:
A. Increase pressure
B. Prevent reverse flow contamination
C. Drain faster
D. Reduce pipe size
Correct Answer: B
Rationale: They prevent contaminated water from entering clean water
supply.
