Kansas Journeyman Plumber Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. The primary purpose of a plumbing vent system is to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Protect trap seals and allow sewer gases to escape
D. Speed up drainage
Correct Answer: C
Rationales: Vent systems balance air pressure in drainage systems,
protecting trap seals and safely releasing sewer gases to prevent
siphonage and odors.
2. What is the minimum slope required for a 3-inch horizontal drainage
pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. Level
Correct Answer: B
Rationales: Plumbing codes require a minimum slope of 1/4 inch per foot
for pipes 2½ inches or smaller, and 1/4 inch is commonly applied to 3-inch
drains for proper flow.
, 3. Which type of valve is required on a water heater cold-water supply
line?
A. Gate valve
B. Globe valve
C. Full-port shutoff valve
D. Check valve
Correct Answer: C
Rationales: A full-port shutoff valve allows unrestricted flow and enables
isolation of the water heater for servicing.
4. The maximum allowable water temperature delivered to a public
hand-washing lavatory is:
A. 90°F
B. 100°F
C. 110°F
D. 120°F
Correct Answer: C
Rationales: Codes limit lavatory water temperature to 110°F to prevent
scalding injuries.
5. What fitting is used to change direction in a horizontal drainage pipe
by 90 degrees?
A. Tee
B. Sanitary tee
C. Long-sweep elbow
D. Short-turn elbow
Correct Answer: C
Rationales: Long-sweep elbows reduce turbulence and are required for
smooth directional changes in drainage systems.
6. Which material is commonly approved for potable water distribution?
A. ABS
B. Galvanized steel only
, C. Copper tubing
D. Black iron
Correct Answer: C
Rationales: Copper tubing is corrosion-resistant and widely approved for
potable water supply systems.
7. A trap seal is primarily designed to:
A. Prevent clogging
B. Increase flow velocity
C. Block sewer gases from entering the building
D. Reduce water usage
Correct Answer: C
Rationales: The water seal in a trap prevents harmful sewer gases from
entering occupied spaces.
8. What is the minimum trap seal depth required for most fixtures?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Correct Answer: B
Rationales: A minimum 2-inch trap seal ensures effective gas blockage
without risk of evaporation.
9. Which device protects a potable water system from backflow?
A. Pressure regulator
B. Gate valve
C. Backflow preventer
D. Air chamber
Correct Answer: C
Rationales: Backflow preventers stop contaminated water from reversing
flow into the potable supply.
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. The primary purpose of a plumbing vent system is to:
A. Increase water pressure
B. Prevent pipe corrosion
C. Protect trap seals and allow sewer gases to escape
D. Speed up drainage
Correct Answer: C
Rationales: Vent systems balance air pressure in drainage systems,
protecting trap seals and safely releasing sewer gases to prevent
siphonage and odors.
2. What is the minimum slope required for a 3-inch horizontal drainage
pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. Level
Correct Answer: B
Rationales: Plumbing codes require a minimum slope of 1/4 inch per foot
for pipes 2½ inches or smaller, and 1/4 inch is commonly applied to 3-inch
drains for proper flow.
, 3. Which type of valve is required on a water heater cold-water supply
line?
A. Gate valve
B. Globe valve
C. Full-port shutoff valve
D. Check valve
Correct Answer: C
Rationales: A full-port shutoff valve allows unrestricted flow and enables
isolation of the water heater for servicing.
4. The maximum allowable water temperature delivered to a public
hand-washing lavatory is:
A. 90°F
B. 100°F
C. 110°F
D. 120°F
Correct Answer: C
Rationales: Codes limit lavatory water temperature to 110°F to prevent
scalding injuries.
5. What fitting is used to change direction in a horizontal drainage pipe
by 90 degrees?
A. Tee
B. Sanitary tee
C. Long-sweep elbow
D. Short-turn elbow
Correct Answer: C
Rationales: Long-sweep elbows reduce turbulence and are required for
smooth directional changes in drainage systems.
6. Which material is commonly approved for potable water distribution?
A. ABS
B. Galvanized steel only
, C. Copper tubing
D. Black iron
Correct Answer: C
Rationales: Copper tubing is corrosion-resistant and widely approved for
potable water supply systems.
7. A trap seal is primarily designed to:
A. Prevent clogging
B. Increase flow velocity
C. Block sewer gases from entering the building
D. Reduce water usage
Correct Answer: C
Rationales: The water seal in a trap prevents harmful sewer gases from
entering occupied spaces.
8. What is the minimum trap seal depth required for most fixtures?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Correct Answer: B
Rationales: A minimum 2-inch trap seal ensures effective gas blockage
without risk of evaporation.
9. Which device protects a potable water system from backflow?
A. Pressure regulator
B. Gate valve
C. Backflow preventer
D. Air chamber
Correct Answer: C
Rationales: Backflow preventers stop contaminated water from reversing
flow into the potable supply.
