AZ C-37 (CR-37) PLUMBING CONTRACTOR
ACTUAL EXAM 2026-2027 COMPLETE EXAM
REAL QUESTIONS AND CORRECT VERIFIED
ANSWERS WITH DETAILED RATIONALES (100%
RELIABLE SOLUTIONS) AZ C-37 (CR-37)
PLUMBING CONTRACTOR EXAM 2026
CURRENTLY UPDATED EXAM |GUARANTEED
PASS A+ |INSTANT DOWNLOAD PDF
1. A commercial building's drainage system requires a 4-inch horizontal branch.
Per the IPC, what is the minimum slope required for this pipe to ensure proper self-
scouring velocity?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
Answer: B
Rationale: The International Plumbing Code (IPC) mandates a minimum slope of
1/8 inch per foot for horizontal drainage pipes 3 inches in diameter or larger. This
slope is sufficient to maintain a self-scouring velocity of 2 feet per second, which
prevents solids from settling and ensures the system remains clear. Pipes smaller
than 3 inches typically require a steeper 1/4 inch per foot slope.
,2. A licensed C-37 plumbing contractor is asked to install a gas-fired space heater
in a commercial workshop. According to the license's scope of work, is this
permissible, and under what condition?
A) Yes, the scope includes gas or oil fired space heaters and furnaces, excluding
ductwork.
B) No, any work on gas-fired appliances falls exclusively under a specialty gas
fitting license.
C) Yes, the scope includes the installation of the appliance, including all ductwork
and air distribution systems.
D) No, the C-37 license is strictly limited to water and sanitary systems.
Answer: A
Rationale: The Arizona C-37 (CR-37) scope of work explicitly includes "gas or oil
fired space heaters and furnaces, excluding duct work." The contractor can install
the gas piping and connect the appliance, but the ductwork for air distribution falls
under a separate HVAC license classification, such as a C-39 (Refrigeration and
Air Conditioning) or C-38 (Warm Air Heating) license.
3. What is the primary purpose of a vent pipe in a Drainage, Waste, and Vent
(DWV) system?
A) To carry waste from fixtures to the sewer.
B) To provide a path for heat to escape from hot water lines.
C) To allow fresh air into the system to equalize pressure and prevent trap
siphonage.
D) To filter solid waste before it enters the building drain.
Answer: C
Rationale: Vent pipes are critical for protecting trap seals. Without proper venting,
the flow of wastewater can create a vacuum in the drainage system, siphoning the
water out of fixture traps. By allowing air into the system, vents equalize the
,pressure, preventing this siphonage and ensuring that the trap's water seal remains
intact to block sewer gases from entering the building.
4. Under Arizona law (ARS §32-1151), which of the following actions is
considered unprofessional conduct for a plumbing contractor?
A) Submitting a bid significantly lower than a competitor's bid.
B) Failing to complete a signed contract without legal excuse.
C) Recommending a more expensive, but durable, material to a client.
D) Requesting a progress payment as stipulated in the contract terms.
Answer: B
Rationale: ARS §32-1151(A)(3) defines the "abandonment or willful failure to
perform, without justification, any contract or project" as unprofessional conduct.
This can lead to disciplinary action by the Arizona Registrar of Contractors (ROC),
including fines or license suspension. Submitting a low bid, recommending better
materials, or requesting contractual payments are not, in themselves,
unprofessional conduct.
5. What is the minimum size building sewer required by most plumbing codes
when serving a commercial building with multiple water closets?
A) 2 inches
B) 3 inches
C) 4 inches
D) 6 inches
Answer: C
Rationale: Plumbing codes, such as the UPC and IPC, typically mandate a
minimum building sewer size of 4 inches when serving more than one water closet.
A 3-inch sewer is generally the minimum for a single-family residence with one
, water closet, but the larger 4-inch size is required to ensure adequate capacity and
reduce the risk of clogging in commercial applications serving multiple fixtures.
6. To prevent corrosion when connecting a copper water supply line to a
galvanized steel pipe, what fitting is required?
A) A standard brass coupling.
B) A dielectric union.
C) A direct threaded connection.
D) An epoxy-bonded fitting.
Answer: B
Rationale: Connecting dissimilar metals like copper and galvanized steel creates an
electrolytic reaction that leads to galvanic corrosion, rapidly degrading the pipe. A
dielectric union is a specialized fitting that breaks the electrical continuity between
the two metals, preventing this corrosive reaction and ensuring the longevity of the
piping system.
7. A C-37 contractor is installing piping for a commercial hot water heating system.
What are the maximum operating pressure and temperature limits for this work?
A) 15 psig and 220°F
B) 30 psig and 220°F
C) 50 psig and 250°F
D) 100 psig and 300°F
Answer: B
Rationale: The C-37 scope of work authorizes the installation of piping for "hot
water heating and hot water supply systems operating at pressures not exceeding
30 psig or temperatures not exceeding 220°F." Systems exceeding these limits
typically fall under a boiler license, such as a C-46 (Steamfitting).
ACTUAL EXAM 2026-2027 COMPLETE EXAM
REAL QUESTIONS AND CORRECT VERIFIED
ANSWERS WITH DETAILED RATIONALES (100%
RELIABLE SOLUTIONS) AZ C-37 (CR-37)
PLUMBING CONTRACTOR EXAM 2026
CURRENTLY UPDATED EXAM |GUARANTEED
PASS A+ |INSTANT DOWNLOAD PDF
1. A commercial building's drainage system requires a 4-inch horizontal branch.
Per the IPC, what is the minimum slope required for this pipe to ensure proper self-
scouring velocity?
A) 1/16 inch per foot
B) 1/8 inch per foot
C) 1/4 inch per foot
D) 1/2 inch per foot
Answer: B
Rationale: The International Plumbing Code (IPC) mandates a minimum slope of
1/8 inch per foot for horizontal drainage pipes 3 inches in diameter or larger. This
slope is sufficient to maintain a self-scouring velocity of 2 feet per second, which
prevents solids from settling and ensures the system remains clear. Pipes smaller
than 3 inches typically require a steeper 1/4 inch per foot slope.
,2. A licensed C-37 plumbing contractor is asked to install a gas-fired space heater
in a commercial workshop. According to the license's scope of work, is this
permissible, and under what condition?
A) Yes, the scope includes gas or oil fired space heaters and furnaces, excluding
ductwork.
B) No, any work on gas-fired appliances falls exclusively under a specialty gas
fitting license.
C) Yes, the scope includes the installation of the appliance, including all ductwork
and air distribution systems.
D) No, the C-37 license is strictly limited to water and sanitary systems.
Answer: A
Rationale: The Arizona C-37 (CR-37) scope of work explicitly includes "gas or oil
fired space heaters and furnaces, excluding duct work." The contractor can install
the gas piping and connect the appliance, but the ductwork for air distribution falls
under a separate HVAC license classification, such as a C-39 (Refrigeration and
Air Conditioning) or C-38 (Warm Air Heating) license.
3. What is the primary purpose of a vent pipe in a Drainage, Waste, and Vent
(DWV) system?
A) To carry waste from fixtures to the sewer.
B) To provide a path for heat to escape from hot water lines.
C) To allow fresh air into the system to equalize pressure and prevent trap
siphonage.
D) To filter solid waste before it enters the building drain.
Answer: C
Rationale: Vent pipes are critical for protecting trap seals. Without proper venting,
the flow of wastewater can create a vacuum in the drainage system, siphoning the
water out of fixture traps. By allowing air into the system, vents equalize the
,pressure, preventing this siphonage and ensuring that the trap's water seal remains
intact to block sewer gases from entering the building.
4. Under Arizona law (ARS §32-1151), which of the following actions is
considered unprofessional conduct for a plumbing contractor?
A) Submitting a bid significantly lower than a competitor's bid.
B) Failing to complete a signed contract without legal excuse.
C) Recommending a more expensive, but durable, material to a client.
D) Requesting a progress payment as stipulated in the contract terms.
Answer: B
Rationale: ARS §32-1151(A)(3) defines the "abandonment or willful failure to
perform, without justification, any contract or project" as unprofessional conduct.
This can lead to disciplinary action by the Arizona Registrar of Contractors (ROC),
including fines or license suspension. Submitting a low bid, recommending better
materials, or requesting contractual payments are not, in themselves,
unprofessional conduct.
5. What is the minimum size building sewer required by most plumbing codes
when serving a commercial building with multiple water closets?
A) 2 inches
B) 3 inches
C) 4 inches
D) 6 inches
Answer: C
Rationale: Plumbing codes, such as the UPC and IPC, typically mandate a
minimum building sewer size of 4 inches when serving more than one water closet.
A 3-inch sewer is generally the minimum for a single-family residence with one
, water closet, but the larger 4-inch size is required to ensure adequate capacity and
reduce the risk of clogging in commercial applications serving multiple fixtures.
6. To prevent corrosion when connecting a copper water supply line to a
galvanized steel pipe, what fitting is required?
A) A standard brass coupling.
B) A dielectric union.
C) A direct threaded connection.
D) An epoxy-bonded fitting.
Answer: B
Rationale: Connecting dissimilar metals like copper and galvanized steel creates an
electrolytic reaction that leads to galvanic corrosion, rapidly degrading the pipe. A
dielectric union is a specialized fitting that breaks the electrical continuity between
the two metals, preventing this corrosive reaction and ensuring the longevity of the
piping system.
7. A C-37 contractor is installing piping for a commercial hot water heating system.
What are the maximum operating pressure and temperature limits for this work?
A) 15 psig and 220°F
B) 30 psig and 220°F
C) 50 psig and 250°F
D) 100 psig and 300°F
Answer: B
Rationale: The C-37 scope of work authorizes the installation of piping for "hot
water heating and hot water supply systems operating at pressures not exceeding
30 psig or temperatures not exceeding 220°F." Systems exceeding these limits
typically fall under a boiler license, such as a C-46 (Steamfitting).
