Allentown Plumbing License Examination (ICC
Plumbing Code Exam) Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a plumbing code?
A. To establish plumbing material prices
B. To regulate the appearance of plumbing fixtures
C. To establish minimum requirements for safe and sanitary plumbing
systems
D. To determine contractor profit margins
Answer: C. To establish minimum requirements for safe and sanitary
plumbing systems
Rationale: Plumbing codes establish minimum standards intended to
protect public health, safety, and welfare. They address matters such as
water supply, drainage, venting, fixtures, materials, installation, and
protection against contamination.
, 2. Which plumbing system is primarily responsible for carrying
potable water to fixtures?
A. Sanitary drainage system
B. Water distribution system
C. Storm drainage system
D. Vent system
Answer: B. Water distribution system
Rationale: The water distribution system conveys potable water from
the water supply source to plumbing fixtures and other approved points
of use. Drainage and vent systems serve different functions.
3. What is the primary function of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering a building
C. Increase drainage velocity
D. Filter potable water
Answer: B. Prevent sewer gases from entering a building
Rationale: A trap maintains a water seal between the drainage system
and the occupied space. This water seal prevents objectionable gases
and odors from entering the building through fixture drains.
4. Which fixture normally requires a trap?
,A. Water closet
B. Hose bibb
C. Roof drain
D. Water heater
Answer: A. Water closet
Rationale: Plumbing fixtures that discharge into the sanitary drainage
system generally require an approved trap or an integral trap
arrangement. A water closet incorporates its own integral trap.
5. What is the purpose of a plumbing vent system?
A. To increase water pressure
B. To introduce air into the drainage system and protect trap seals
C. To remove sediment from water
D. To supply hot water to fixtures
Answer: B. To introduce air into the drainage system and protect trap
seals
Rationale: Proper venting allows air movement within the drainage
system, helps maintain atmospheric pressure, and protects trap seals
from excessive pressure differences that could cause siphonage or
backpressure.
, 6. Which fitting is generally used to change the direction of a
drainage pipe?
A. Coupling
B. Elbow
C. Union
D. Bushing
Answer: B. Elbow
Rationale: Elbows are designed to change the direction of piping. In
sanitary drainage systems, fittings must be selected and installed so
that they promote smooth flow and minimize obstruction.
7. What is the purpose of a cleanout?
A. To regulate water temperature
B. To provide access for cleaning and maintaining drainage piping
C. To prevent freezing
D. To increase water pressure
Answer: B. To provide access for cleaning and maintaining drainage
piping
Rationale: Cleanouts provide access to drainage piping so blockages can
be removed and the piping can be inspected or maintained. They must
be located and sized according to applicable code requirements.
Plumbing Code Exam) Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a plumbing code?
A. To establish plumbing material prices
B. To regulate the appearance of plumbing fixtures
C. To establish minimum requirements for safe and sanitary plumbing
systems
D. To determine contractor profit margins
Answer: C. To establish minimum requirements for safe and sanitary
plumbing systems
Rationale: Plumbing codes establish minimum standards intended to
protect public health, safety, and welfare. They address matters such as
water supply, drainage, venting, fixtures, materials, installation, and
protection against contamination.
, 2. Which plumbing system is primarily responsible for carrying
potable water to fixtures?
A. Sanitary drainage system
B. Water distribution system
C. Storm drainage system
D. Vent system
Answer: B. Water distribution system
Rationale: The water distribution system conveys potable water from
the water supply source to plumbing fixtures and other approved points
of use. Drainage and vent systems serve different functions.
3. What is the primary function of a plumbing trap?
A. Increase water pressure
B. Prevent sewer gases from entering a building
C. Increase drainage velocity
D. Filter potable water
Answer: B. Prevent sewer gases from entering a building
Rationale: A trap maintains a water seal between the drainage system
and the occupied space. This water seal prevents objectionable gases
and odors from entering the building through fixture drains.
4. Which fixture normally requires a trap?
,A. Water closet
B. Hose bibb
C. Roof drain
D. Water heater
Answer: A. Water closet
Rationale: Plumbing fixtures that discharge into the sanitary drainage
system generally require an approved trap or an integral trap
arrangement. A water closet incorporates its own integral trap.
5. What is the purpose of a plumbing vent system?
A. To increase water pressure
B. To introduce air into the drainage system and protect trap seals
C. To remove sediment from water
D. To supply hot water to fixtures
Answer: B. To introduce air into the drainage system and protect trap
seals
Rationale: Proper venting allows air movement within the drainage
system, helps maintain atmospheric pressure, and protects trap seals
from excessive pressure differences that could cause siphonage or
backpressure.
, 6. Which fitting is generally used to change the direction of a
drainage pipe?
A. Coupling
B. Elbow
C. Union
D. Bushing
Answer: B. Elbow
Rationale: Elbows are designed to change the direction of piping. In
sanitary drainage systems, fittings must be selected and installed so
that they promote smooth flow and minimize obstruction.
7. What is the purpose of a cleanout?
A. To regulate water temperature
B. To provide access for cleaning and maintaining drainage piping
C. To prevent freezing
D. To increase water pressure
Answer: B. To provide access for cleaning and maintaining drainage
piping
Rationale: Cleanouts provide access to drainage piping so blockages can
be removed and the piping can be inspected or maintained. They must
be located and sized according to applicable code requirements.
