Georgia Journeyman Plumber
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Reduce pipe diameter
Answer: Prevent sewer gases from entering the building
Rationale: A plumbing trap retains a water seal that prevents sewer gases and
odors from entering occupied spaces.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Sanitary tee
B. Wye
C. Quarter bend
D. Coupling
,Answer: Quarter bend
Rationale: A quarter bend changes the direction of piping approximately 90
degrees and is commonly used where permitted by the applicable drainage
rules.
3. What is the minimum slope commonly required for a 3-inch horizontal
drainage pipe under standard plumbing-code 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
Answer: 1/4 inch per foot
Rationale: Smaller drainage piping generally requires sufficient slope to
maintain self-scouring flow. A commonly specified minimum for 3-inch and
smaller drainage piping is 1/4 inch per foot.
4. What is the primary function of a cleanout?
A. Increase water pressure
B. Provide access for clearing blockages
C. Prevent freezing
D. Reduce pipe noise
Answer: Provide access for clearing blockages
Rationale: Cleanouts provide access to drainage piping so obstructions can be
removed and the system can be maintained.
5. Which material is commonly used for potable-water distribution piping?
A. Cast iron soil pipe
B. PVC pressure-rated pipe
C. ABS DWV pipe
D. Clay sewer pipe
Answer: PVC pressure-rated pipe
,Rationale: Approved pressure-rated PVC products can be used for potable-water
distribution where the product and installation comply with the applicable code.
6. What does DWV stand for?
A. Domestic Water Valve
B. Drain, Waste, and Vent
C. Direct Water Volume
D. Drain Water Vacuum
Answer: Drain, Waste, and Vent
Rationale: DWV describes piping systems that collect wastewater and provide
ventilation to protect drainage-system function and trap seals.
7. What is the purpose of a vent system?
A. Supply drinking water
B. Increase water temperature
C. Protect trap seals and allow proper drainage-system airflow
D. Increase water pressure
Answer: Protect trap seals and allow proper drainage-system airflow
Rationale: Proper venting helps equalize pressure within the drainage system
and protects trap seals from siphonage and backpressure.
8. Which fitting is generally preferred for connecting a branch drain to a
horizontal drain?
A. Wye
B. Straight coupling
C. Cap
D. Bushing
Answer: Wye
Rationale: A wye provides a smoother directional transition for drainage flow
and is commonly used for branch connections.
, 9. What is the purpose of a water shutoff valve?
A. Prevent sewer gases
B. Control water flow to a fixture or section of piping
C. Vent the drainage system
D. Increase pipe diameter
Answer: Control water flow to a fixture or section of piping
Rationale: Shutoff valves allow water service to be isolated for maintenance,
repairs, or fixture replacement.
10.Which device protects potable water from contamination caused by
backflow?
A. Cleanout
B. Backflow-prevention device
C. Trap primer
D. Drain grate
Answer: Backflow-prevention device
Rationale: Backflow-prevention devices protect potable water supplies from
potentially contaminated water flowing in the reverse direction.
11.What is back-siphonage?
A. Excessive drainage velocity
B. Reverse flow caused by negative pressure in the water supply
C. Water leaking from a trap
D. Sewer gas entering a building
Answer: Reverse flow caused by negative pressure in the water supply
Rationale: Back-siphonage occurs when pressure in the potable-water system
falls below atmospheric or downstream pressure, allowing contaminated water
to be drawn backward.
12.What is backpressure backflow?
A. Reverse flow caused by downstream pressure exceeding supply pressure
Examination Practice Exam 2026 | 100
Questions & Answers with Detailed
Rationales | Complete Exam Prep &
Study Guide
1. What is the primary purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering the building
C. Increase drainage velocity
D. Reduce pipe diameter
Answer: Prevent sewer gases from entering the building
Rationale: A plumbing trap retains a water seal that prevents sewer gases and
odors from entering occupied spaces.
2. Which fitting is commonly used to change the direction of a drainage pipe
by 90 degrees?
A. Sanitary tee
B. Wye
C. Quarter bend
D. Coupling
,Answer: Quarter bend
Rationale: A quarter bend changes the direction of piping approximately 90
degrees and is commonly used where permitted by the applicable drainage
rules.
3. What is the minimum slope commonly required for a 3-inch horizontal
drainage pipe under standard plumbing-code 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
Answer: 1/4 inch per foot
Rationale: Smaller drainage piping generally requires sufficient slope to
maintain self-scouring flow. A commonly specified minimum for 3-inch and
smaller drainage piping is 1/4 inch per foot.
4. What is the primary function of a cleanout?
A. Increase water pressure
B. Provide access for clearing blockages
C. Prevent freezing
D. Reduce pipe noise
Answer: Provide access for clearing blockages
Rationale: Cleanouts provide access to drainage piping so obstructions can be
removed and the system can be maintained.
5. Which material is commonly used for potable-water distribution piping?
A. Cast iron soil pipe
B. PVC pressure-rated pipe
C. ABS DWV pipe
D. Clay sewer pipe
Answer: PVC pressure-rated pipe
,Rationale: Approved pressure-rated PVC products can be used for potable-water
distribution where the product and installation comply with the applicable code.
6. What does DWV stand for?
A. Domestic Water Valve
B. Drain, Waste, and Vent
C. Direct Water Volume
D. Drain Water Vacuum
Answer: Drain, Waste, and Vent
Rationale: DWV describes piping systems that collect wastewater and provide
ventilation to protect drainage-system function and trap seals.
7. What is the purpose of a vent system?
A. Supply drinking water
B. Increase water temperature
C. Protect trap seals and allow proper drainage-system airflow
D. Increase water pressure
Answer: Protect trap seals and allow proper drainage-system airflow
Rationale: Proper venting helps equalize pressure within the drainage system
and protects trap seals from siphonage and backpressure.
8. Which fitting is generally preferred for connecting a branch drain to a
horizontal drain?
A. Wye
B. Straight coupling
C. Cap
D. Bushing
Answer: Wye
Rationale: A wye provides a smoother directional transition for drainage flow
and is commonly used for branch connections.
, 9. What is the purpose of a water shutoff valve?
A. Prevent sewer gases
B. Control water flow to a fixture or section of piping
C. Vent the drainage system
D. Increase pipe diameter
Answer: Control water flow to a fixture or section of piping
Rationale: Shutoff valves allow water service to be isolated for maintenance,
repairs, or fixture replacement.
10.Which device protects potable water from contamination caused by
backflow?
A. Cleanout
B. Backflow-prevention device
C. Trap primer
D. Drain grate
Answer: Backflow-prevention device
Rationale: Backflow-prevention devices protect potable water supplies from
potentially contaminated water flowing in the reverse direction.
11.What is back-siphonage?
A. Excessive drainage velocity
B. Reverse flow caused by negative pressure in the water supply
C. Water leaking from a trap
D. Sewer gas entering a building
Answer: Reverse flow caused by negative pressure in the water supply
Rationale: Back-siphonage occurs when pressure in the potable-water system
falls below atmospheric or downstream pressure, allowing contaminated water
to be drawn backward.
12.What is backpressure backflow?
A. Reverse flow caused by downstream pressure exceeding supply pressure
