Maryland Journeyman Plumber/Gas
Fitter Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A plumbing trap is primarily designed to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Prevent sewer gases from entering occupied spaces
D. Improve drainage velocity
Rationale: A trap maintains a water seal that blocks sewer gases from
entering buildings while still allowing wastewater to pass through.
2. What is the minimum slope generally required for a 3-inch horizontal
drainage pipe under the IPC?
A. 1/8 inch per foot
B. 1/16 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
Rationale: The IPC permits a minimum slope of 1/8 inch per foot for
horizontal drainage piping 3 inches and larger under specified conditions.
, 3. Which fitting should be used to connect a horizontal drain to a vertical
stack?
A. Tee fitting
B. Coupling
C. Wye fitting
D. Cap fitting
Rationale: Wye fittings provide smoother directional flow and reduce
turbulence in drainage systems.
4. What is the primary purpose of venting in a plumbing drainage
system?
A. Increase water pressure
B. Prevent pipe freezing
C. Protect trap seals and allow proper drainage
D. Filter wastewater
Rationale: Venting equalizes pressure within the drainage system and
prevents trap siphonage.
5. Cross-connection control is intended to:
A. Improve drainage
B. Increase fixture flow
C. Prevent contamination of potable water
D. Reduce water pressure
Rationale: Cross-connection control devices protect drinking water from
contamination caused by backflow conditions.
6. Backflow occurs when:
A. Water pressure increases
B. Wastewater evaporates
C. Water flows opposite its intended direction
D. Water enters a vent stack
, Rationale: Backflow is an undesirable reversal of flow that may
contaminate potable water supplies.
7. Which device provides the highest level of protection against
backsiphonage and backpressure?
A. Atmospheric vacuum breaker
B. Double-check valve assembly
C. Pressure vacuum breaker
D. Reduced pressure principle assembly
Rationale: Reduced pressure principle assemblies provide superior
protection against both backsiphonage and backpressure.
8. What is the primary purpose of a cleanout?
A. Measure pressure
B. Vent a drainage system
C. Provide access for cleaning and inspection
D. Support piping
Rationale: Cleanouts allow maintenance personnel to remove blockages
and inspect drainage piping.
9. A fixture unit is used to:
A. Measure water quality
B. Calculate gas pressure
C. Estimate plumbing demand loads
D. Determine pipe thickness
Rationale: Fixture units help size water supply and drainage systems based
on anticipated usage.
10. Which pipe material is commonly used for residential DWV
systems?
A. Black steel
B. Copper Type K
Fitter Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A plumbing trap is primarily designed to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Prevent sewer gases from entering occupied spaces
D. Improve drainage velocity
Rationale: A trap maintains a water seal that blocks sewer gases from
entering buildings while still allowing wastewater to pass through.
2. What is the minimum slope generally required for a 3-inch horizontal
drainage pipe under the IPC?
A. 1/8 inch per foot
B. 1/16 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
Rationale: The IPC permits a minimum slope of 1/8 inch per foot for
horizontal drainage piping 3 inches and larger under specified conditions.
, 3. Which fitting should be used to connect a horizontal drain to a vertical
stack?
A. Tee fitting
B. Coupling
C. Wye fitting
D. Cap fitting
Rationale: Wye fittings provide smoother directional flow and reduce
turbulence in drainage systems.
4. What is the primary purpose of venting in a plumbing drainage
system?
A. Increase water pressure
B. Prevent pipe freezing
C. Protect trap seals and allow proper drainage
D. Filter wastewater
Rationale: Venting equalizes pressure within the drainage system and
prevents trap siphonage.
5. Cross-connection control is intended to:
A. Improve drainage
B. Increase fixture flow
C. Prevent contamination of potable water
D. Reduce water pressure
Rationale: Cross-connection control devices protect drinking water from
contamination caused by backflow conditions.
6. Backflow occurs when:
A. Water pressure increases
B. Wastewater evaporates
C. Water flows opposite its intended direction
D. Water enters a vent stack
, Rationale: Backflow is an undesirable reversal of flow that may
contaminate potable water supplies.
7. Which device provides the highest level of protection against
backsiphonage and backpressure?
A. Atmospheric vacuum breaker
B. Double-check valve assembly
C. Pressure vacuum breaker
D. Reduced pressure principle assembly
Rationale: Reduced pressure principle assemblies provide superior
protection against both backsiphonage and backpressure.
8. What is the primary purpose of a cleanout?
A. Measure pressure
B. Vent a drainage system
C. Provide access for cleaning and inspection
D. Support piping
Rationale: Cleanouts allow maintenance personnel to remove blockages
and inspect drainage piping.
9. A fixture unit is used to:
A. Measure water quality
B. Calculate gas pressure
C. Estimate plumbing demand loads
D. Determine pipe thickness
Rationale: Fixture units help size water supply and drainage systems based
on anticipated usage.
10. Which pipe material is commonly used for residential DWV
systems?
A. Black steel
B. Copper Type K
