Drainage, Waste & Vent (DWV) Flashcards
6 cards from real Plumbing practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Drainage, Waste & Vent (DWV) flashcards as text
What is a 'stack vent' in a plumbing system?
Answer: The extension of a soil or waste stack above the highest fixture connection
A stack vent is the upper portion of a soil or waste stack that extends above the highest fixture connection and terminates in open air to vent the system.
What is the minimum height above a roof surface for a vent terminal (vent through roof)?
Answer: 12 inches
The IPC requires vent terminals to extend at least 6 inches above the roof surface to prevent blockage by debris, snow, or ice.
What is the term for the main vertical drain pipe that carries waste from upper floors to the building drain?
Answer: Soil stack
A soil stack is the large vertical pipe that collects waste from fixtures on multiple floors and carries it down to the building drain.
Which type of fitting is required when changing direction from horizontal to vertical in a drain system?
Answer: Long-sweep 90-degree elbow
A long-sweep 90-degree elbow is required for direction changes in drain lines because its gradual curve maintains flow velocity and prevents blockages.
What is 'indirect waste' in plumbing?
Answer: Discharge from an appliance that drains into an open receptor rather than directly to the drainage system
Indirect waste is when an appliance (like a dishwasher or HVAC condensate line) drains into an open air gap receptor rather than connecting directly to the sanitary drainage system.
What prevents sewer gases from entering a building through a floor drain that is rarely used?
Answer: A trap primer or trap seal preservative
A trap primer periodically adds water to the floor drain trap to replenish the water seal that evaporates in infrequently used drains.