Drainage, Waste, and Venting 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 Venting flashcards as text
Which fitting is required when a drain changes direction from vertical to horizontal?
Answer: Long-sweep 1/4 bend or combination wye and 1/8 bend
A long-sweep 1/4 bend or a combination wye and 1/8 bend is required when transitioning from vertical to horizontal to ensure smooth, non-turbulent flow.
What is the maximum vertical distance a fixture drain may drop before connecting to the trap arm?
Answer: The trap arm must be level or pitched to drain only
The trap arm must be level or pitched toward the drain at no more than 1/4 inch per foot — no section between the trap and vent may be vertical.
A 3-inch soil stack may NOT receive the discharge from which fixture?
Answer: Water closet
Water closets require a minimum 3-inch drain, but the stack receiving water closet discharge must also be at least 3 inches — however the trap itself must be 3 inches minimum, making the stack size at least 3 inches; a 2-inch stack cannot receive a water closet.
In a DWV system, what does the term 'developed length' mean?
Answer: The total length measured along the centerline of the pipe including fittings
Developed length is the total length measured along the centerline of the pipe, following all bends and offsets, used for calculating vent lengths and trap arm limits.
Which condition is considered a cross-connection in a DWV system?
Answer: A drain pipe connected directly to a potable water supply pipe
A cross-connection occurs when a drain pipe is directly connected to a potable water supply, creating a potential for contamination.
What is the minimum horizontal distance required between a trap and its vent connection measured along the trap arm?
Answer: No minimum — the vent can be directly at the trap outlet
There is no code-specified minimum distance between the trap outlet and the vent connection — the vent may connect immediately after the trap.
Island fixture venting is a special technique used when a vent pipe cannot rise vertically because of which obstacle?
Answer: A kitchen island with no wall access nearby
Island fixture venting is required for sinks in kitchen islands where no nearby wall is available for the vent pipe to rise through.