ARKANSAS MASTER PLUMBER EXAM NEWEST
UPDATE 2026 VERSION 100 QUESTIONS &
DETAILED CORRECT ANSWERS GRADE A+
(100% SUCCESS) BRAND NEW VERSION!!
1. Which of the following is the minimum slope required for a 2-inch
horizontal drainage pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Rationale: The Arkansas Plumbing Code requires a minimum slope
of 1/4 inch per foot for 2-inch drainage pipes to ensure proper
flow.
2. What type of vent is used to prevent siphoning of water traps?
A. Relief vent
B. Circuit vent
C. Stack vent
D. Air admittance valve
Answer: C
Rationale: Stack vents extend through the roof to maintain proper
air pressure and prevent siphoning of traps.
3. Which material is NOT typically approved for potable water supply
lines in Arkansas?
A. Copper
, B. PEX
C. PVC Schedule 40
D. Galvanized steel
Answer: C
Rationale: PVC Schedule 40 is generally prohibited for potable
water; CPVC or copper is used instead.
4. What is the maximum distance a horizontal water closet drain can
be from the trap to the vent?
A. 2 feet
B. 3 feet
C. 5 feet
D. 6 feet
Answer: D
Rationale: Code limits the distance to prevent trap siphoning and
maintain proper venting.
5. Which type of valve is typically used to isolate water heaters?
A. Gate valve
B. Ball valve
C. Check valve
D. Pressure-reducing valve
Answer: B
Rationale: Ball valves are preferred for isolation because they
provide a tight shut-off and durability.
6. In a water distribution system, what is the recommended
maximum temperature for domestic hot water?
A. 120°F
B. 140°F
, C. 160°F
D. 180°F
Answer: A
Rationale: 120°F minimizes the risk of scalding and complies with
plumbing codes.
7. Which method is commonly used to join copper pipes?
A. Threading
B. Soldering
C. Compression fitting
D. All of the above
Answer: D
Rationale: Copper can be joined by threading, soldering, or
compression depending on the application.
8. What is the primary purpose of a P-trap?
A. Prevent backflow
B. Trap debris
C. Prevent sewer gases from entering a building
D. Increase water pressure
Answer: C
Rationale: P-traps maintain a water seal to block sewer gases.
9. Which type of water heater is most energy-efficient for residential
use?
A. Tankless
B. Electric storage tank
C. Gas storage tank
D. Solar thermal
Answer: A
, Rationale: Tankless water heaters heat water on demand,
reducing standby energy losses.
10. What is the minimum burial depth for water supply piping in
Arkansas to prevent freezing?
A. 12 inches
B. 18 inches
C. 24 inches
D. 36 inches
Answer: B
Rationale: Water piping must be buried below the frost line;
typically 18 inches in Arkansas.
11. What is the function of a backwater valve?
A. Prevent water hammer
B. Prevent sewage backup
C. Filter sediments
D. Regulate pressure
Answer: B
Rationale: Backwater valves prevent sewage from reversing into
the building.
12. Which is the standard pipe size for a residential kitchen sink
drain?
A. 1 inch
B. 1.5 inches
C. 2 inches
D. 3 inches
Answer: B
UPDATE 2026 VERSION 100 QUESTIONS &
DETAILED CORRECT ANSWERS GRADE A+
(100% SUCCESS) BRAND NEW VERSION!!
1. Which of the following is the minimum slope required for a 2-inch
horizontal drainage pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Answer: B
Rationale: The Arkansas Plumbing Code requires a minimum slope
of 1/4 inch per foot for 2-inch drainage pipes to ensure proper
flow.
2. What type of vent is used to prevent siphoning of water traps?
A. Relief vent
B. Circuit vent
C. Stack vent
D. Air admittance valve
Answer: C
Rationale: Stack vents extend through the roof to maintain proper
air pressure and prevent siphoning of traps.
3. Which material is NOT typically approved for potable water supply
lines in Arkansas?
A. Copper
, B. PEX
C. PVC Schedule 40
D. Galvanized steel
Answer: C
Rationale: PVC Schedule 40 is generally prohibited for potable
water; CPVC or copper is used instead.
4. What is the maximum distance a horizontal water closet drain can
be from the trap to the vent?
A. 2 feet
B. 3 feet
C. 5 feet
D. 6 feet
Answer: D
Rationale: Code limits the distance to prevent trap siphoning and
maintain proper venting.
5. Which type of valve is typically used to isolate water heaters?
A. Gate valve
B. Ball valve
C. Check valve
D. Pressure-reducing valve
Answer: B
Rationale: Ball valves are preferred for isolation because they
provide a tight shut-off and durability.
6. In a water distribution system, what is the recommended
maximum temperature for domestic hot water?
A. 120°F
B. 140°F
, C. 160°F
D. 180°F
Answer: A
Rationale: 120°F minimizes the risk of scalding and complies with
plumbing codes.
7. Which method is commonly used to join copper pipes?
A. Threading
B. Soldering
C. Compression fitting
D. All of the above
Answer: D
Rationale: Copper can be joined by threading, soldering, or
compression depending on the application.
8. What is the primary purpose of a P-trap?
A. Prevent backflow
B. Trap debris
C. Prevent sewer gases from entering a building
D. Increase water pressure
Answer: C
Rationale: P-traps maintain a water seal to block sewer gases.
9. Which type of water heater is most energy-efficient for residential
use?
A. Tankless
B. Electric storage tank
C. Gas storage tank
D. Solar thermal
Answer: A
, Rationale: Tankless water heaters heat water on demand,
reducing standby energy losses.
10. What is the minimum burial depth for water supply piping in
Arkansas to prevent freezing?
A. 12 inches
B. 18 inches
C. 24 inches
D. 36 inches
Answer: B
Rationale: Water piping must be buried below the frost line;
typically 18 inches in Arkansas.
11. What is the function of a backwater valve?
A. Prevent water hammer
B. Prevent sewage backup
C. Filter sediments
D. Regulate pressure
Answer: B
Rationale: Backwater valves prevent sewage from reversing into
the building.
12. Which is the standard pipe size for a residential kitchen sink
drain?
A. 1 inch
B. 1.5 inches
C. 2 inches
D. 3 inches
Answer: B
