Kansas Master Plumber Exam Questions
And Correct Answers (Verified Answers)
Plus Rationale 2026 Q&A
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 2026 Q&A
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.
|
