AZ C-37 Plumbing Contractor Exam —
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Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. What does the Arizona C-37 Plumbing Contractor classification
primarily authorize?
A. Electrical installation and repair
B. Installation, alteration, and repair of plumbing systems within the
classification scope
C. Structural steel erection
D. Roofing and waterproofing
Answer: B. Installation, alteration, and repair of plumbing systems within
the classification scope
,Rationale: The C-37 classification covers plumbing work including water
supply, sanitary drainage, venting, fixtures, piping, appliances, and several
related systems within its defined scope.
2. Which piping system is generally included within the C-37 plumbing
classification?
A. Refrigerant piping
B. Water supply piping
C. Electrical conduit
D. Telephone conduit
Answer: B. Water supply piping
Rationale: Water supply piping, fixtures, appliances, pressure vessels, and
tanks are within the C-37 scope, subject to applicable limitations.
3. What is the primary purpose of a sanitary drainage system?
A. Supply potable water
B. Supply fuel gas
C. Carry wastewater away from plumbing fixtures
D. Increase water pressure
Answer: C. Carry wastewater away from plumbing fixtures
,Rationale: Sanitary drainage systems collect and convey wastewater and
other permitted wastes to an approved point of disposal.
4. What is the primary function of a plumbing vent system?
A. Increase water temperature
B. Protect trap seals and allow proper drainage-system airflow
C. Supply potable water
D. Filter wastewater
Answer: B. Protect trap seals and allow proper drainage-system airflow
Rationale: Venting balances pressure within the drainage system and helps
prevent siphonage or pressure conditions that could compromise trap
seals.
5. Which fitting is commonly used to change the direction of a drainage
pipe?
A. Coupling
B. Union
C. Elbow
D. Reducer
Answer: C. Elbow
, Rationale: Elbows are designed to change piping direction while
maintaining a continuous flow path.
6. What is the purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering occupied spaces
C. Heat water
D. Filter drinking water
Answer: B. Prevent sewer gases from entering occupied spaces
Rationale: A properly designed and maintained trap retains a water seal
that blocks gases from the drainage system.
7. Which fixture normally requires a trap?
A. Water heater
B. Hose bibb
C. Lavatory
D. Water meter
Answer: C. Lavatory
Rationale: Plumbing fixtures that discharge wastewater into the drainage
system generally require an approved trap to protect against sewer gases.
8. What is a water hammer?
Practice Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What does the Arizona C-37 Plumbing Contractor classification
primarily authorize?
A. Electrical installation and repair
B. Installation, alteration, and repair of plumbing systems within the
classification scope
C. Structural steel erection
D. Roofing and waterproofing
Answer: B. Installation, alteration, and repair of plumbing systems within
the classification scope
,Rationale: The C-37 classification covers plumbing work including water
supply, sanitary drainage, venting, fixtures, piping, appliances, and several
related systems within its defined scope.
2. Which piping system is generally included within the C-37 plumbing
classification?
A. Refrigerant piping
B. Water supply piping
C. Electrical conduit
D. Telephone conduit
Answer: B. Water supply piping
Rationale: Water supply piping, fixtures, appliances, pressure vessels, and
tanks are within the C-37 scope, subject to applicable limitations.
3. What is the primary purpose of a sanitary drainage system?
A. Supply potable water
B. Supply fuel gas
C. Carry wastewater away from plumbing fixtures
D. Increase water pressure
Answer: C. Carry wastewater away from plumbing fixtures
,Rationale: Sanitary drainage systems collect and convey wastewater and
other permitted wastes to an approved point of disposal.
4. What is the primary function of a plumbing vent system?
A. Increase water temperature
B. Protect trap seals and allow proper drainage-system airflow
C. Supply potable water
D. Filter wastewater
Answer: B. Protect trap seals and allow proper drainage-system airflow
Rationale: Venting balances pressure within the drainage system and helps
prevent siphonage or pressure conditions that could compromise trap
seals.
5. Which fitting is commonly used to change the direction of a drainage
pipe?
A. Coupling
B. Union
C. Elbow
D. Reducer
Answer: C. Elbow
, Rationale: Elbows are designed to change piping direction while
maintaining a continuous flow path.
6. What is the purpose of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering occupied spaces
C. Heat water
D. Filter drinking water
Answer: B. Prevent sewer gases from entering occupied spaces
Rationale: A properly designed and maintained trap retains a water seal
that blocks gases from the drainage system.
7. Which fixture normally requires a trap?
A. Water heater
B. Hose bibb
C. Lavatory
D. Water meter
Answer: C. Lavatory
Rationale: Plumbing fixtures that discharge wastewater into the drainage
system generally require an approved trap to protect against sewer gases.
8. What is a water hammer?
