NEVADA PLUMBING CONTRACTOR EXAM] QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 /2027 Q&A | INSTANT DOWNLOAD PDF
Core Domains
• Nevada Licensing, C-1 Classification, and Exam Structure (CMS & Trade
Exams)
• Uniform Plumbing Code (UPC) & Nevada State Amendments (Gas Systems,
Cleanouts)
• Fixtures, Equipment, and Water Heaters/Venting
• Hydronics (≤200,000 BTU) and Solar Water Heating
• Piping, Hangers, Supports, and Joints
• Drain, Waste, and Vent (DWV) Systems (Sizing, Traps, Slope)
• Water Supply, Distribution, and Backflow Prevention
• Fuel Gas Piping (NFPA 54 & 58)
• Safety (OSHA 1926) and Environmental Regulations
Introduction
This comprehensive assessment is designed for candidates preparing for the
Nevada Plumbing Contractor (C-1D) licensing examination. The exam covers the
Uniform Plumbing Code (UPC) and specific Nevada state regulations, focusing on
DWV systems, venting, water supply, and gas piping. Using a multiple-choice and
scenario-based structure, it tests your ability to apply code requirements in real-
world situations. Successful completion demonstrates readiness to manage
plumbing projects and pass the official state exam.
SECTION ONE: QUESTIONS 1–100
1. What is the minimum slope required for a horizontal drainage pipe 4 inches
or larger under the Uniform Plumbing Code (UPC) adopted by Nevada?
A. 1/16 inch per foot
B. 1/8 inch per foot
,C. 1/4 inch per foot
D. 1/2 inch per foot
B
RATIONALE: Under the UPC, horizontal drainage pipes 4 inches and larger
require a minimum slope of 1/8 inch per foot, while pipes 3 inches and smaller
require 1/4 inch per foot to ensure proper self-cleaning velocity .
2. What is the minimum size required for a building sewer when water closets
are connected to the system?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
C
RATIONALE: When water closets are connected, the minimum building
sewer size is 4 inches, as water closets require a minimum 3-inch drain connection
and the building sewer must accommodate the total DFU load .
3. Under the UPC, what type of backflow prevention device is required for a
high-hazard cross-connection?
A. Atmospheric vacuum breaker
B. Dual check valve
C. Reduced pressure zone (RPZ) assembly
D. Hose bibb vacuum breaker
C
RATIONALE: The UPC requires a Reduced Pressure Zone (RPZ) backflow
prevention assembly for high-hazard cross-connections where backpressure or
backsiphonage could contaminate the potable water supply .
4. What is the minimum vent pipe size allowed under the UPC?
A. 1 inch
B. 1-1/4 inches
C. 1-1/2 inches
D. 2 inches
, B
RATIONALE: Under the UPC, no vent pipe shall be less than 1-1/4 inches in
diameter. This minimum applies to all vent types including individual, branch, and
circuit vents .
5. What is the minimum trap seal depth required for most plumbing fixtures
under the UPC?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
B
RATIONALE: The minimum trap seal depth is 2 inches and the maximum is 4
inches. The trap seal prevents sewer gases from entering the building .
6. What is the DFU (Drainage Fixture Unit) value for a standard water closet
under the UPC?
A. 2 DFU
B. 3 DFU
C. 4 DFU
D. 6 DFU
C
RATIONALE: Under the UPC, a standard water closet is rated at 4 DFU. This
value is used to calculate drainage pipe sizing for the entire system .
7. What is the maximum static water pressure allowed in a building
distribution system under the UPC?
A. 60 psi
B. 80 psi
C. 100 psi
D. 120 psi
B
RATIONALE: The UPC limits maximum static water pressure in a building
distribution system to 80 psi. When pressure exceeds this limit, a pressure-reducing
valve must be installed .
, 8. The Nevada C-1D Plumbing Contractor trade exam is administered by
which testing organization?
A. Prometric
B. PSI
C. Pearson VUE
D. GITS
B
RATIONALE: Nevada contractor examinations are administered by PSI on
behalf of the Nevada State Contractors Board .
9. How many questions are on the Nevada C-1D Plumbing Contractor trade
exam?
A. 60 questions
B. 70 questions
C. 80 questions
D. 120 questions
C
RATIONALE: The C-1D Plumbing Contractor trade exam consists of 80
questions with a 3-hour time limit .
10. What is the passing score required for the Nevada C-1D Plumbing
Contractor trade exam?
A. 65%
B. 70%
C. 75%
D. 80%
B
RATIONALE: A passing score of 70% is required (56 correct out of 80
questions) for the C-1D Plumbing Contractor trade exam .
11. What is the minimum experience requirement to qualify for a Nevada
Plumbing Contractor license?
A. 2 years as a journeyman
B. 3 years as a foreman
C. 4 years at journey-level or as a foreman/supervisor
D. 5 years as a contractor
CORRECT ANSWERS (VERIFIED ANSWERS) PLUS
RATIONALES 2026 /2027 Q&A | INSTANT DOWNLOAD PDF
Core Domains
• Nevada Licensing, C-1 Classification, and Exam Structure (CMS & Trade
Exams)
• Uniform Plumbing Code (UPC) & Nevada State Amendments (Gas Systems,
Cleanouts)
• Fixtures, Equipment, and Water Heaters/Venting
• Hydronics (≤200,000 BTU) and Solar Water Heating
• Piping, Hangers, Supports, and Joints
• Drain, Waste, and Vent (DWV) Systems (Sizing, Traps, Slope)
• Water Supply, Distribution, and Backflow Prevention
• Fuel Gas Piping (NFPA 54 & 58)
• Safety (OSHA 1926) and Environmental Regulations
Introduction
This comprehensive assessment is designed for candidates preparing for the
Nevada Plumbing Contractor (C-1D) licensing examination. The exam covers the
Uniform Plumbing Code (UPC) and specific Nevada state regulations, focusing on
DWV systems, venting, water supply, and gas piping. Using a multiple-choice and
scenario-based structure, it tests your ability to apply code requirements in real-
world situations. Successful completion demonstrates readiness to manage
plumbing projects and pass the official state exam.
SECTION ONE: QUESTIONS 1–100
1. What is the minimum slope required for a horizontal drainage pipe 4 inches
or larger under the Uniform Plumbing Code (UPC) adopted by Nevada?
A. 1/16 inch per foot
B. 1/8 inch per foot
,C. 1/4 inch per foot
D. 1/2 inch per foot
B
RATIONALE: Under the UPC, horizontal drainage pipes 4 inches and larger
require a minimum slope of 1/8 inch per foot, while pipes 3 inches and smaller
require 1/4 inch per foot to ensure proper self-cleaning velocity .
2. What is the minimum size required for a building sewer when water closets
are connected to the system?
A. 2 inches
B. 3 inches
C. 4 inches
D. 6 inches
C
RATIONALE: When water closets are connected, the minimum building
sewer size is 4 inches, as water closets require a minimum 3-inch drain connection
and the building sewer must accommodate the total DFU load .
3. Under the UPC, what type of backflow prevention device is required for a
high-hazard cross-connection?
A. Atmospheric vacuum breaker
B. Dual check valve
C. Reduced pressure zone (RPZ) assembly
D. Hose bibb vacuum breaker
C
RATIONALE: The UPC requires a Reduced Pressure Zone (RPZ) backflow
prevention assembly for high-hazard cross-connections where backpressure or
backsiphonage could contaminate the potable water supply .
4. What is the minimum vent pipe size allowed under the UPC?
A. 1 inch
B. 1-1/4 inches
C. 1-1/2 inches
D. 2 inches
, B
RATIONALE: Under the UPC, no vent pipe shall be less than 1-1/4 inches in
diameter. This minimum applies to all vent types including individual, branch, and
circuit vents .
5. What is the minimum trap seal depth required for most plumbing fixtures
under the UPC?
A. 1 inch
B. 2 inches
C. 3 inches
D. 4 inches
B
RATIONALE: The minimum trap seal depth is 2 inches and the maximum is 4
inches. The trap seal prevents sewer gases from entering the building .
6. What is the DFU (Drainage Fixture Unit) value for a standard water closet
under the UPC?
A. 2 DFU
B. 3 DFU
C. 4 DFU
D. 6 DFU
C
RATIONALE: Under the UPC, a standard water closet is rated at 4 DFU. This
value is used to calculate drainage pipe sizing for the entire system .
7. What is the maximum static water pressure allowed in a building
distribution system under the UPC?
A. 60 psi
B. 80 psi
C. 100 psi
D. 120 psi
B
RATIONALE: The UPC limits maximum static water pressure in a building
distribution system to 80 psi. When pressure exceeds this limit, a pressure-reducing
valve must be installed .
, 8. The Nevada C-1D Plumbing Contractor trade exam is administered by
which testing organization?
A. Prometric
B. PSI
C. Pearson VUE
D. GITS
B
RATIONALE: Nevada contractor examinations are administered by PSI on
behalf of the Nevada State Contractors Board .
9. How many questions are on the Nevada C-1D Plumbing Contractor trade
exam?
A. 60 questions
B. 70 questions
C. 80 questions
D. 120 questions
C
RATIONALE: The C-1D Plumbing Contractor trade exam consists of 80
questions with a 3-hour time limit .
10. What is the passing score required for the Nevada C-1D Plumbing
Contractor trade exam?
A. 65%
B. 70%
C. 75%
D. 80%
B
RATIONALE: A passing score of 70% is required (56 correct out of 80
questions) for the C-1D Plumbing Contractor trade exam .
11. What is the minimum experience requirement to qualify for a Nevada
Plumbing Contractor license?
A. 2 years as a journeyman
B. 3 years as a foreman
C. 4 years at journey-level or as a foreman/supervisor
D. 5 years as a contractor
