[TEXAS JOURNEYMAN PLUMBER LICENSE EXAM] – QUESTIONS
AND ANSWERS | VERIFIED AND WELL DETAILED ANSWERS |
PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM
UPDATE | EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. A plumber is installing a water distribution system in a residential building. Which pipe
material is MOST appropriate for hot water supply lines?
A. ABS
B. PVC
C. CPVC
D. Cast iron
════════════════════
Correct Answer: C. CPVC
Rationale:
CPVC is specifically rated for hot and cold potable water systems due to its higher
temperature tolerance. PVC and ABS are generally limited to cold water or drainage systems,
while cast iron is used for drainage, not supply lines.
2. What is the primary purpose of a P-trap in a plumbing fixture?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Improve drainage speed
D. Filter debris from wastewater
════════════════════
Correct Answer: B. Prevent sewer gases from entering the building
Rationale:
A P-trap retains water in its bend, forming a seal that blocks sewer gases. It does not increase
pressure, filter debris, or enhance drainage speed.
3. Which tool is MOST appropriate for cutting large diameter steel pipe?
A. Hacksaw
,B. Tubing cutter
C. Pipe cutter chain-type
D. Basin wrench
════════════════════
Correct Answer: C. Pipe cutter chain-type
Rationale:
Chain-type pipe cutters are designed for large steel pipes, providing even pressure around the
pipe. Hacksaws are slower and less precise, tubing cutters are for small copper tubing, and
basin wrenches are for faucet installation.
4. What is the minimum slope required for a 4-inch building drain according to standard
plumbing practice?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
════════════════════
Correct Answer: B. 1/8 inch per foot
Rationale:
A 4-inch drain typically requires a minimum slope of 1/8 inch per foot to ensure proper waste
flow without causing solids separation or clogging.
5. Which fitting is used to change the direction of a pipe run by 90 degrees in a drainage
system?
A. Tee
B. Wye
C. Elbow
D. Coupling
════════════════════
Correct Answer: C. Elbow
Rationale:
Elbows are specifically designed to change flow direction, commonly at 45° or 90°. Tees and
wyes are for branching, while couplings join straight pipe sections.
,6. What is the function of an air admittance valve (AAV)?
A. Releases sewer gases outdoors
B. Allows air into the drainage system to prevent siphoning
C. Increases water pressure in fixtures
D. Controls wastewater flow rate
════════════════════
Correct Answer: B. Allows air into the drainage system to prevent siphoning
Rationale:
An AAV permits air entry into the system when negative pressure occurs, preventing trap
siphonage. It does not vent gases outdoors or regulate flow rate.
7. Which material is commonly used for underground water service lines due to corrosion
resistance?
A. Galvanized steel
B. Copper Type M
C. HDPE
D. Black steel
════════════════════
Correct Answer: C. HDPE
Rationale:
High-Density Polyethylene (HDPE) is flexible, corrosion-resistant, and widely used for
underground water service lines. Steel materials corrode over time underground.
8. A fixture unit is BEST defined as:
A. Pipe diameter measurement
B. A measure of drainage slope
C. A load estimation for plumbing fixtures
D. Water pressure measurement
════════════════════
Correct Answer: C. A load estimation for plumbing fixtures
Rationale:
, Fixture units represent the probable demand a fixture places on a plumbing system, helping
engineers size pipes correctly.
9. What is the MOST likely cause of a water hammer in a plumbing system?
A. Excessive pipe insulation
B. Rapid valve closure
C. Low water temperature
D. Oversized piping
════════════════════
Correct Answer: B. Rapid valve closure
Rationale:
Water hammer occurs when flowing water is suddenly stopped, causing a pressure
shockwave. Fast-closing valves are the primary cause.
10. Which venting method is commonly used for multiple fixtures in a bathroom group?
A. Individual venting
B. Loop venting
C. Wet venting
D. Stack venting
════════════════════
Correct Answer: C. Wet venting
Rationale:
Wet venting allows multiple fixtures to share a common vent through a properly sized drain
line, commonly used in bathroom groups.
11. What is the main purpose of a cleanout in a drainage system?
A. Increase flow rate
B. Provide access for clearing blockages
C. Reduce odor
D. Control water temperature
════════════════════
Correct Answer: B. Provide access for clearing blockages
Rationale:
AND ANSWERS | VERIFIED AND WELL DETAILED ANSWERS |
PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM
UPDATE | EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. A plumber is installing a water distribution system in a residential building. Which pipe
material is MOST appropriate for hot water supply lines?
A. ABS
B. PVC
C. CPVC
D. Cast iron
════════════════════
Correct Answer: C. CPVC
Rationale:
CPVC is specifically rated for hot and cold potable water systems due to its higher
temperature tolerance. PVC and ABS are generally limited to cold water or drainage systems,
while cast iron is used for drainage, not supply lines.
2. What is the primary purpose of a P-trap in a plumbing fixture?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Improve drainage speed
D. Filter debris from wastewater
════════════════════
Correct Answer: B. Prevent sewer gases from entering the building
Rationale:
A P-trap retains water in its bend, forming a seal that blocks sewer gases. It does not increase
pressure, filter debris, or enhance drainage speed.
3. Which tool is MOST appropriate for cutting large diameter steel pipe?
A. Hacksaw
,B. Tubing cutter
C. Pipe cutter chain-type
D. Basin wrench
════════════════════
Correct Answer: C. Pipe cutter chain-type
Rationale:
Chain-type pipe cutters are designed for large steel pipes, providing even pressure around the
pipe. Hacksaws are slower and less precise, tubing cutters are for small copper tubing, and
basin wrenches are for faucet installation.
4. What is the minimum slope required for a 4-inch building drain according to standard
plumbing practice?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
════════════════════
Correct Answer: B. 1/8 inch per foot
Rationale:
A 4-inch drain typically requires a minimum slope of 1/8 inch per foot to ensure proper waste
flow without causing solids separation or clogging.
5. Which fitting is used to change the direction of a pipe run by 90 degrees in a drainage
system?
A. Tee
B. Wye
C. Elbow
D. Coupling
════════════════════
Correct Answer: C. Elbow
Rationale:
Elbows are specifically designed to change flow direction, commonly at 45° or 90°. Tees and
wyes are for branching, while couplings join straight pipe sections.
,6. What is the function of an air admittance valve (AAV)?
A. Releases sewer gases outdoors
B. Allows air into the drainage system to prevent siphoning
C. Increases water pressure in fixtures
D. Controls wastewater flow rate
════════════════════
Correct Answer: B. Allows air into the drainage system to prevent siphoning
Rationale:
An AAV permits air entry into the system when negative pressure occurs, preventing trap
siphonage. It does not vent gases outdoors or regulate flow rate.
7. Which material is commonly used for underground water service lines due to corrosion
resistance?
A. Galvanized steel
B. Copper Type M
C. HDPE
D. Black steel
════════════════════
Correct Answer: C. HDPE
Rationale:
High-Density Polyethylene (HDPE) is flexible, corrosion-resistant, and widely used for
underground water service lines. Steel materials corrode over time underground.
8. A fixture unit is BEST defined as:
A. Pipe diameter measurement
B. A measure of drainage slope
C. A load estimation for plumbing fixtures
D. Water pressure measurement
════════════════════
Correct Answer: C. A load estimation for plumbing fixtures
Rationale:
, Fixture units represent the probable demand a fixture places on a plumbing system, helping
engineers size pipes correctly.
9. What is the MOST likely cause of a water hammer in a plumbing system?
A. Excessive pipe insulation
B. Rapid valve closure
C. Low water temperature
D. Oversized piping
════════════════════
Correct Answer: B. Rapid valve closure
Rationale:
Water hammer occurs when flowing water is suddenly stopped, causing a pressure
shockwave. Fast-closing valves are the primary cause.
10. Which venting method is commonly used for multiple fixtures in a bathroom group?
A. Individual venting
B. Loop venting
C. Wet venting
D. Stack venting
════════════════════
Correct Answer: C. Wet venting
Rationale:
Wet venting allows multiple fixtures to share a common vent through a properly sized drain
line, commonly used in bathroom groups.
11. What is the main purpose of a cleanout in a drainage system?
A. Increase flow rate
B. Provide access for clearing blockages
C. Reduce odor
D. Control water temperature
════════════════════
Correct Answer: B. Provide access for clearing blockages
Rationale:
