JOURNEYMAN PLUMBER PRACTICE
EXAM 1 QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025
1. What is the minimum size drain required for a shower?
A) 1 1/2 inches
B) 2 inches
C) 2 1/2 inches
D) 3 inches
The code requires a 2-inch minimum drain for showers to allow sufficient flow
and prevent clogging.
2. What is the maximum allowable length for a trap arm for a 2-inch pipe?
A) 2 feet
B) 3 feet
C) 5 feet
D) 8 feet
,A 2-inch pipe has a maximum trap arm length of 5 feet according to standard
code.
3. What is the minimum slope for horizontal drainage piping?
A) 1/4 inch per foot
B) 1/2 inch per foot
C) 1/8 inch per foot
D) 1 inch per foot
The standard minimum slope is 1/4 inch per foot to ensure proper drainage.
4. Which type of pipe is commonly used for underground drainage?
A) Copper
B) PVC
C) PEX
D) CPVC
PVC is durable, easy to install, and commonly used for underground drainage.
5. What does DWV stand for in plumbing systems?
A) Domestic Water Valve
B) Drainage Water Vent
C) Drain, Waste, and Vent
D) Down Water Vent
DWV refers to the system that removes wastewater and vents sewer gases.
,6. Which fitting is used to connect three pipes at 90 degrees to each other?
A) Tee
B) Wye
C) Elbow
D) Coupling
A tee fitting allows for a perpendicular connection of three pipes.
7. What is the minimum air gap required for a 1-inch supply pipe to prevent
backflow?
A) 1 inch
B) 2 inches
C) 3 inches
D) 4 inches
The air gap must be at least twice the diameter of the pipe, so 2 inches for a 1-
inch pipe.
8. Which component prevents sewer gases from entering a building?
A) Trap
B) Cleanout
C) Vent
D) Union
Traps retain water that acts as a barrier against sewer gases.
, 9. A water heater relief valve should discharge to:
A) The sewer
B) A visible and safe location
C) A sink
D) The floor drain directly
The relief valve must discharge to a visible, safe location to indicate failure or
overpressure.
10. What is the color code for potable water lines in piping identification?
A) Yellow
B) Red
C) Blue
D) Green
Blue is the standard color for identifying potable water lines.
(Only 10 questions shown here due to space, but I will continue with the next 40 in
a follow-up message.)
Here is the continuation of the Journeyman Plumber Practice Exam (Questions
11–50). Correct answers are in bold and rationales in italic bold.
11. Which valve is best for throttling flow?
A) Ball valve
B) Globe valve
EXAM 1 QUESTIONS AND CORRECT
ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2025
1. What is the minimum size drain required for a shower?
A) 1 1/2 inches
B) 2 inches
C) 2 1/2 inches
D) 3 inches
The code requires a 2-inch minimum drain for showers to allow sufficient flow
and prevent clogging.
2. What is the maximum allowable length for a trap arm for a 2-inch pipe?
A) 2 feet
B) 3 feet
C) 5 feet
D) 8 feet
,A 2-inch pipe has a maximum trap arm length of 5 feet according to standard
code.
3. What is the minimum slope for horizontal drainage piping?
A) 1/4 inch per foot
B) 1/2 inch per foot
C) 1/8 inch per foot
D) 1 inch per foot
The standard minimum slope is 1/4 inch per foot to ensure proper drainage.
4. Which type of pipe is commonly used for underground drainage?
A) Copper
B) PVC
C) PEX
D) CPVC
PVC is durable, easy to install, and commonly used for underground drainage.
5. What does DWV stand for in plumbing systems?
A) Domestic Water Valve
B) Drainage Water Vent
C) Drain, Waste, and Vent
D) Down Water Vent
DWV refers to the system that removes wastewater and vents sewer gases.
,6. Which fitting is used to connect three pipes at 90 degrees to each other?
A) Tee
B) Wye
C) Elbow
D) Coupling
A tee fitting allows for a perpendicular connection of three pipes.
7. What is the minimum air gap required for a 1-inch supply pipe to prevent
backflow?
A) 1 inch
B) 2 inches
C) 3 inches
D) 4 inches
The air gap must be at least twice the diameter of the pipe, so 2 inches for a 1-
inch pipe.
8. Which component prevents sewer gases from entering a building?
A) Trap
B) Cleanout
C) Vent
D) Union
Traps retain water that acts as a barrier against sewer gases.
, 9. A water heater relief valve should discharge to:
A) The sewer
B) A visible and safe location
C) A sink
D) The floor drain directly
The relief valve must discharge to a visible, safe location to indicate failure or
overpressure.
10. What is the color code for potable water lines in piping identification?
A) Yellow
B) Red
C) Blue
D) Green
Blue is the standard color for identifying potable water lines.
(Only 10 questions shown here due to space, but I will continue with the next 40 in
a follow-up message.)
Here is the continuation of the Journeyman Plumber Practice Exam (Questions
11–50). Correct answers are in bold and rationales in italic bold.
11. Which valve is best for throttling flow?
A) Ball valve
B) Globe valve
