Alberta Plumber Apprenticeship
Certification Exam (First Period) Practice
(Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of a trap in a drainage system?
A. Provide mechanical filtration
B. Prevent sewer gases from entering the building
C. Increase water pressure
D. Prevent pipe corrosion
Rationale: Traps hold a water seal that blocks harmful sewer gases from
migrating into occupied spaces.
2. What is the minimum water seal depth required for a trap?
A. 25 mm
B. 100 mm
C. 50 mm
D. 150 mm
Rationale: Most codes require a 50 mm (2-inch) water seal to maintain
effective gas blocking.
3. A vent prevents which of the following?
A. Water hammer
B. Trap siphonage
C. Pipe corrosion
D. Backflow
,Rationale: Vents equalize air pressure to prevent traps from being siphoned
dry.
4. Which type of copper tube is typically used for water distribution?
A. Type DWV
B. Type K only
C. Type L
D. Type M
Rationale: Type L strikes a balance between wall thickness and cost,
making it suitable for water supply lines.
5. What is the primary purpose of a cleanout?
A. Increase flow velocity
B. Allow water hammer control
C. Provide access for cleaning the drainage system
D. Prevent siphonage
Rationale: Cleanouts give access points for clearing blockages.
6. What is the typical slope for a horizontal drainage pipe ≤ 3 inches?
A. 1%
B. 2%
C. 4%
D. 10%
Rationale: A 2% slope (¼ inch per foot) ensures proper drainage without
excessive velocity.
7. What material is commonly used for DWV systems?
A. Steel
B. Copper
C. PEX
D. PVC
Rationale: PVC is lightweight, easy to install, and widely allowed in DWV
systems.
8. A backflow preventer protects against…
, A. Clogging
B. Contamination of potable water
C. Pipe corrosion
D. Air circulation in vents
Rationale: Backflow prevention ensures contaminants cannot enter the
clean water system.
9. Hard water contains high levels of:
A. Sodium
B. Iron
C. Calcium and magnesium
D. Carbon dioxide
Rationale: Hardness is caused by calcium and magnesium mineral content.
10. The term “fixture unit” measures:
A. Weight of a fixture
B. Probable discharge load of a fixture
C. Size of drain
D. Pressure rating
Rationale: Fixture units estimate probable demand on a drainage or water
system.
11. What is the minimum size for a building drain?
A. 2"
B. 3"
C. 4"
D. 6"
Rationale: Building drains normally require at least 4 inches for capacity
and code compliance.
12. Galvanic corrosion occurs when:
A. Water is too pure
B. Dissimilar metals contact in presence of an electrolyte
Certification Exam (First Period) Practice
(Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A| Instant Download Pdf
1. What is the primary purpose of a trap in a drainage system?
A. Provide mechanical filtration
B. Prevent sewer gases from entering the building
C. Increase water pressure
D. Prevent pipe corrosion
Rationale: Traps hold a water seal that blocks harmful sewer gases from
migrating into occupied spaces.
2. What is the minimum water seal depth required for a trap?
A. 25 mm
B. 100 mm
C. 50 mm
D. 150 mm
Rationale: Most codes require a 50 mm (2-inch) water seal to maintain
effective gas blocking.
3. A vent prevents which of the following?
A. Water hammer
B. Trap siphonage
C. Pipe corrosion
D. Backflow
,Rationale: Vents equalize air pressure to prevent traps from being siphoned
dry.
4. Which type of copper tube is typically used for water distribution?
A. Type DWV
B. Type K only
C. Type L
D. Type M
Rationale: Type L strikes a balance between wall thickness and cost,
making it suitable for water supply lines.
5. What is the primary purpose of a cleanout?
A. Increase flow velocity
B. Allow water hammer control
C. Provide access for cleaning the drainage system
D. Prevent siphonage
Rationale: Cleanouts give access points for clearing blockages.
6. What is the typical slope for a horizontal drainage pipe ≤ 3 inches?
A. 1%
B. 2%
C. 4%
D. 10%
Rationale: A 2% slope (¼ inch per foot) ensures proper drainage without
excessive velocity.
7. What material is commonly used for DWV systems?
A. Steel
B. Copper
C. PEX
D. PVC
Rationale: PVC is lightweight, easy to install, and widely allowed in DWV
systems.
8. A backflow preventer protects against…
, A. Clogging
B. Contamination of potable water
C. Pipe corrosion
D. Air circulation in vents
Rationale: Backflow prevention ensures contaminants cannot enter the
clean water system.
9. Hard water contains high levels of:
A. Sodium
B. Iron
C. Calcium and magnesium
D. Carbon dioxide
Rationale: Hardness is caused by calcium and magnesium mineral content.
10. The term “fixture unit” measures:
A. Weight of a fixture
B. Probable discharge load of a fixture
C. Size of drain
D. Pressure rating
Rationale: Fixture units estimate probable demand on a drainage or water
system.
11. What is the minimum size for a building drain?
A. 2"
B. 3"
C. 4"
D. 6"
Rationale: Building drains normally require at least 4 inches for capacity
and code compliance.
12. Galvanic corrosion occurs when:
A. Water is too pure
B. Dissimilar metals contact in presence of an electrolyte
