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
What is the minimum slope required for a 3-inch horizontal drain pipe per the Uniform Plumbing Code?
Answer: 1/4 inch per foot
The UPC requires 1/4 inch per foot (2% grade) slope for horizontal drain pipes 3 inches and larger.
A wet vent is permitted to serve which combination of fixtures?
Answer: Bathtub and lavatory on the same floor level
A wet vent commonly serves a bathtub and lavatory located on the same floor, where the drain also acts as the vent.
When installing a drum trap, where must the outlet be located relative to the inlet?
Answer: At least 2 inches above the inlet
The outlet of a drum trap must be located at least 2 inches above the inlet to maintain the water seal.
Which type of vent is installed on the downstream side of a fixture trap to prevent siphoning?
Answer: Back vent (individual vent)
A back vent, also called an individual vent, connects to the fixture drain on the downstream side of the trap to prevent trap siphoning.
What is the maximum developed length of a 1.5-inch trap arm from trap weir to vent?
Answer: 42 inches
Per the UPC, a 1.5-inch trap arm has a maximum developed length of 42 inches (3.5 feet) from the trap weir to the vent.
A sanitary tee may be used in a drainage system in which orientation?
Answer: In a vertical stack receiving horizontal branch connections
Sanitary tees are approved for use in the vertical position where a horizontal branch connects to a vertical stack.
What is the minimum number of fixture units a 4-inch building drain can carry at 1/4-inch-per-foot slope?
Answer: 160 DFUs
A 4-inch building drain sloped at 1/4 inch per foot has a rated capacity of 160 drainage fixture units (DFUs) per the UPC drainage load tables.