Alberta Plumber Apprenticeship Certification Exam
(Third Period) Questions And Correct Answers
,
, 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
• Correct Answer: B) Prevent sewer gases from entering the building
• Rationale: A trap holds a water seal that blocks harmful sewer gases from
migrating up the pipe and into occupied spaces.
2. What is the minimum water seal depth required for a trap under the
National/Canadian Plumbing Code?
• A) 25 mm (1 inch)
• B) 50 mm (2 inches)
• C) 75 mm (3 inches)
• Correct Answer: B) 50 mm (2 inches)
• *Rationale: Standards require a 50mm (2-inch) water seal to maintain an
effective barrier against gases.*
3. Why is a plumbing vent necessary in a DWV (Drain-Waste-Vent) system?
• A) To prevent water hammer
• B) To prevent trap siphonage
• C) To filter debris
• Correct Answer: B) To prevent trap siphonage
• Rationale: Vents equalize air pressure in the drainage pipes. Without proper
venting, the flow of water can create a vacuum that siphons the water out
of nearby traps.
(Third Period) Questions And Correct Answers
,
, 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
• Correct Answer: B) Prevent sewer gases from entering the building
• Rationale: A trap holds a water seal that blocks harmful sewer gases from
migrating up the pipe and into occupied spaces.
2. What is the minimum water seal depth required for a trap under the
National/Canadian Plumbing Code?
• A) 25 mm (1 inch)
• B) 50 mm (2 inches)
• C) 75 mm (3 inches)
• Correct Answer: B) 50 mm (2 inches)
• *Rationale: Standards require a 50mm (2-inch) water seal to maintain an
effective barrier against gases.*
3. Why is a plumbing vent necessary in a DWV (Drain-Waste-Vent) system?
• A) To prevent water hammer
• B) To prevent trap siphonage
• C) To filter debris
• Correct Answer: B) To prevent trap siphonage
• Rationale: Vents equalize air pressure in the drainage pipes. Without proper
venting, the flow of water can create a vacuum that siphons the water out
of nearby traps.
