Utah Plumbing Contractor Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
1. What is the minimum pipe size for a water service entering a residential
dwelling?
A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1 1/4 inch
Rationale: Utah plumbing code requires a minimum 1-inch water service
line to ensure adequate flow for residential use.
2. What type of pipe is typically approved for underground potable water lines
in Utah?
A. PVC Schedule 40
B. CTS Copper
C. ABS
D. Galvanized steel
Rationale: CTS copper and approved types of PVC are commonly used for
underground potable water service due to durability and safety.
3. What is the maximum allowable spacing for 1-1/2 inch water supply
hangers in a horizontal run?
A. 3 feet
, B. 4 feet
C. 6 feet
D. 8 feet
Rationale: The code specifies that 1-1/2 inch copper or steel pipe must be
supported every 6 feet to prevent sagging.
4. What is the minimum slope required for a 2-inch horizontal DWV pipe?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
Rationale: The slope ensures proper gravity flow of wastewater to prevent
blockages.
5. What is the maximum temperature allowed for domestic water heaters in
Utah without a tempering valve?
A. 120°F
B. 130°F
C. 140°F
D. 160°F
Rationale: The Utah plumbing code allows water heaters to be set up to
140°F; above this, a tempering valve is required for safety.
6. What is the minimum air gap required for a drinking fountain?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Rationale: An air gap prevents backflow contamination; 2 inches is the
code minimum for drinking fountains.
7. Which valve type is preferred for isolating a water heater?
A. Ball valve
B. Gate valve
C. Globe valve
, D. Check valve
Rationale: Gate valves are durable, provide full flow, and are commonly
used to isolate water heaters.
8. What is the minimum trap size for a 1.5-inch lavatory drain?
A. 1 inch
B. 1 1/4 inches
C. 1 1/2 inches
D. 2 inches
Rationale: Lavatories require 1 1/2-inch traps to allow proper drainage
and prevent clogging.
9. What type of vent is required for a 3-inch branch drain serving a sink?
A. Circuit vent
B. Individual vent
C. Wet vent
D. Relief vent
Rationale: A 3-inch branch drain typically requires its own vent to
maintain proper airflow and prevent siphoning of traps.
10.What is the minimum distance a cleanout must be from a building wall?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: Cleanouts must be accessible; 24 inches from a wall ensures
adequate access for maintenance.
11.What is the maximum water pressure allowed for residential plumbing in
Utah?
A. 40 psi
B. 50 psi
C. 80 psi
D. 100 psi
Practice Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A Instant Download Pdf
1. What is the minimum pipe size for a water service entering a residential
dwelling?
A. 1/2 inch
B. 3/4 inch
C. 1 inch
D. 1 1/4 inch
Rationale: Utah plumbing code requires a minimum 1-inch water service
line to ensure adequate flow for residential use.
2. What type of pipe is typically approved for underground potable water lines
in Utah?
A. PVC Schedule 40
B. CTS Copper
C. ABS
D. Galvanized steel
Rationale: CTS copper and approved types of PVC are commonly used for
underground potable water service due to durability and safety.
3. What is the maximum allowable spacing for 1-1/2 inch water supply
hangers in a horizontal run?
A. 3 feet
, B. 4 feet
C. 6 feet
D. 8 feet
Rationale: The code specifies that 1-1/2 inch copper or steel pipe must be
supported every 6 feet to prevent sagging.
4. What is the minimum slope required for a 2-inch horizontal DWV pipe?
A. 1/16 inch per foot
B. 1/8 inch per foot
C. 1/4 inch per foot
D. 1/2 inch per foot
Rationale: The slope ensures proper gravity flow of wastewater to prevent
blockages.
5. What is the maximum temperature allowed for domestic water heaters in
Utah without a tempering valve?
A. 120°F
B. 130°F
C. 140°F
D. 160°F
Rationale: The Utah plumbing code allows water heaters to be set up to
140°F; above this, a tempering valve is required for safety.
6. What is the minimum air gap required for a drinking fountain?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
Rationale: An air gap prevents backflow contamination; 2 inches is the
code minimum for drinking fountains.
7. Which valve type is preferred for isolating a water heater?
A. Ball valve
B. Gate valve
C. Globe valve
, D. Check valve
Rationale: Gate valves are durable, provide full flow, and are commonly
used to isolate water heaters.
8. What is the minimum trap size for a 1.5-inch lavatory drain?
A. 1 inch
B. 1 1/4 inches
C. 1 1/2 inches
D. 2 inches
Rationale: Lavatories require 1 1/2-inch traps to allow proper drainage
and prevent clogging.
9. What type of vent is required for a 3-inch branch drain serving a sink?
A. Circuit vent
B. Individual vent
C. Wet vent
D. Relief vent
Rationale: A 3-inch branch drain typically requires its own vent to
maintain proper airflow and prevent siphoning of traps.
10.What is the minimum distance a cleanout must be from a building wall?
A. 6 inches
B. 12 inches
C. 18 inches
D. 24 inches
Rationale: Cleanouts must be accessible; 24 inches from a wall ensures
adequate access for maintenance.
11.What is the maximum water pressure allowed for residential plumbing in
Utah?
A. 40 psi
B. 50 psi
C. 80 psi
D. 100 psi
