Drainage, Waste, and Vent Systems Flashcards
7 cards from real Journeyman Plumbers Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Drainage, Waste, and Vent Systems flashcards as text
A circuit vent serves:
Answer: A battery of fixtures connected to a common horizontal branch drain
A circuit vent serves a group (battery) of fixtures connected to a horizontal branch drain and provides venting for all fixtures in the group with one vent connection.
What is the minimum diameter of a roof vent terminal (vent through roof) under most plumbing codes?
Answer: 2 inches
The minimum diameter for a vent pipe that terminates through a roof is 2 inches to prevent frost closure in cold climates.
When connecting a clothes washer standpipe to the drainage system, the standpipe must extend at least how high above the trap?
Answer: 24 inches
The IPC requires the clothes washer standpipe to extend at least 18 inches but not more than 42 inches above the trap.
An air admittance valve (AAV) is NOT permitted to:
Answer: Replace the main vent stack that terminates to open air
An AAV cannot replace the main vent stack because the drainage system must have at least one open vent pipe to atmosphere to equalize positive pressures.
What is the correct location for a cleanout on a building drain near the foundation wall?
Answer: Outside the building, at the point where the drain exits the foundation
A cleanout is required near the junction where the building drain exits the foundation so the entire building drain can be rodded from that point.
Which statement about common venting is correct?
Answer: Two fixtures on the same floor level with back-to-back traps may share a single common vent
A common vent connects two fixture drains at the same level into a single vent pipe, and is permitted when both fixture outlets enter the drain stack or branch at the same level.
What is the maximum vertical drop allowed for a trap arm before it connects to the vent?
Answer: The trap arm must slope but cannot drop more than the pipe diameter
A trap arm must slope toward the drain but cannot drop more than one pipe diameter in total vertical drop before reaching the vent connection.