Kansas Master Plumber Exam Questions
And Correct Answers (Verified Answers)
Plus Rationale Q&A| Instant Download
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1. What is the primary purpose of a plumbing vent system?
A. Increase water pressure
B. Prevent pipe corrosion
C. Equalize pressure in the drainage system
D. Remove solids from waste
Rationale: Vent systems allow air to enter drainage piping,
preventing siphonage and ensuring proper trap seals.
2. What is the minimum trap seal depth required by most plumbing
codes?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Rationale: A 2-inch trap seal is the standard minimum to prevent
sewer gas from entering occupied spaces.
3. Which pipe material is approved for above-ground sanitary drainage in
residential buildings?
A. Galvanized steel only
B. PVC or ABS
C. Copper Type K only
D. Cast iron only
Rationale: PVC and ABS are widely approved for above-ground
sanitary drainage applications.
,4. What is the maximum horizontal distance allowed between a trap and
its vent for a 2-inch pipe?
A. 3 feet
B. 5 feet
C. 8 feet
D. 10 feet
Rationale: Codes limit trap arm length to maintain trap seal
integrity; for 2-inch pipe, 5 feet is typical.
5. What fitting is required when connecting a horizontal drain to a
vertical stack?
A. Sanitary tee
B. Combination wye and 1/8 bend
C. Straight tee
D. Vent tee
Rationale: A combination fitting allows smooth flow and reduces
turbulence in drainage systems.
6. What is the required slope for horizontal drainage piping 3 inches in
diameter or smaller?
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: Smaller drainage pipes require a 1/4 inch per foot slope to
maintain proper flow velocity.
7. Which device prevents contaminated water from flowing back into the
potable water system?
A. Pressure regulator
B. Backflow preventer
C. Air chamber
D. Check valve
Rationale: Backflow preventers protect drinking water from cross-
contamination.
8. What type of backflow prevention is required for high-hazard
conditions?
A. Atmospheric vacuum breaker
, B. Double check valve assembly
C. Reduced pressure principle assembly
D. Swing check valve
Rationale: Reduced pressure assemblies provide the highest level of
protection for high-hazard situations.
9. What is the minimum size of a building sewer serving a single-family
dwelling?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Rationale: A 4-inch building sewer is standard to handle residential
waste loads.
10. Which fixture requires a minimum 3-inch drain connection?
A. Lavatory
B. Bathtub
C. Water closet
D. Kitchen sink
Rationale: Water closets discharge large volumes and solids,
requiring a minimum 3-inch drain.
11. What is the function of a cleanout?
A. Venting air
B. Preventing backflow
C. Allowing access for cleaning and inspection
D. Reducing pipe noise
Rationale: Cleanouts provide access points to remove blockages and
inspect piping.
12. How often must cleanouts be installed on horizontal drainage
piping?
A. Every 25 feet
B. Every 100 feet
C. Every 150 feet
D. Only at direction changes
Rationale: Most codes require cleanouts at intervals not exceeding
100 feet.
And Correct Answers (Verified Answers)
Plus Rationale Q&A| Instant Download
1. What is the primary purpose of a plumbing vent system?
A. Increase water pressure
B. Prevent pipe corrosion
C. Equalize pressure in the drainage system
D. Remove solids from waste
Rationale: Vent systems allow air to enter drainage piping,
preventing siphonage and ensuring proper trap seals.
2. What is the minimum trap seal depth required by most plumbing
codes?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Rationale: A 2-inch trap seal is the standard minimum to prevent
sewer gas from entering occupied spaces.
3. Which pipe material is approved for above-ground sanitary drainage in
residential buildings?
A. Galvanized steel only
B. PVC or ABS
C. Copper Type K only
D. Cast iron only
Rationale: PVC and ABS are widely approved for above-ground
sanitary drainage applications.
,4. What is the maximum horizontal distance allowed between a trap and
its vent for a 2-inch pipe?
A. 3 feet
B. 5 feet
C. 8 feet
D. 10 feet
Rationale: Codes limit trap arm length to maintain trap seal
integrity; for 2-inch pipe, 5 feet is typical.
5. What fitting is required when connecting a horizontal drain to a
vertical stack?
A. Sanitary tee
B. Combination wye and 1/8 bend
C. Straight tee
D. Vent tee
Rationale: A combination fitting allows smooth flow and reduces
turbulence in drainage systems.
6. What is the required slope for horizontal drainage piping 3 inches in
diameter or smaller?
A. 1/16 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: Smaller drainage pipes require a 1/4 inch per foot slope to
maintain proper flow velocity.
7. Which device prevents contaminated water from flowing back into the
potable water system?
A. Pressure regulator
B. Backflow preventer
C. Air chamber
D. Check valve
Rationale: Backflow preventers protect drinking water from cross-
contamination.
8. What type of backflow prevention is required for high-hazard
conditions?
A. Atmospheric vacuum breaker
, B. Double check valve assembly
C. Reduced pressure principle assembly
D. Swing check valve
Rationale: Reduced pressure assemblies provide the highest level of
protection for high-hazard situations.
9. What is the minimum size of a building sewer serving a single-family
dwelling?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
Rationale: A 4-inch building sewer is standard to handle residential
waste loads.
10. Which fixture requires a minimum 3-inch drain connection?
A. Lavatory
B. Bathtub
C. Water closet
D. Kitchen sink
Rationale: Water closets discharge large volumes and solids,
requiring a minimum 3-inch drain.
11. What is the function of a cleanout?
A. Venting air
B. Preventing backflow
C. Allowing access for cleaning and inspection
D. Reducing pipe noise
Rationale: Cleanouts provide access points to remove blockages and
inspect piping.
12. How often must cleanouts be installed on horizontal drainage
piping?
A. Every 25 feet
B. Every 100 feet
C. Every 150 feet
D. Only at direction changes
Rationale: Most codes require cleanouts at intervals not exceeding
100 feet.
