Plumbing System Design Flashcards
7 cards from real Master Plumber 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 Plumbing System Design flashcards as text
When designing a drainage system for a multi-story building, which factor primarily determines the required diameter of a vertical stack?
Answer: The number of fixture units connected to the stack
Drainage fixture units (DFUs) connected to a stack determine its required diameter per code tables.
In a low-pressure hot water heating system, the expansion tank is sized based on which primary factor?
Answer: The total water volume of the system and temperature rise
Expansion tank size is calculated from total system water volume and the expected temperature differential to accommodate thermal expansion.
A horizontal drainage branch serving multiple fixtures must have a minimum slope of how many inches per foot according to the IPC for pipes 3 inches and smaller?
Answer: 1/4 inch per foot
The IPC requires a minimum slope of 1/4 inch per foot for horizontal drainage pipes 3 inches in diameter and smaller.
Which venting method allows multiple fixtures on the same horizontal branch to share a single vent without individual fixture vents?
Answer: Circuit venting
Circuit venting serves a battery of fixtures on a horizontal branch with one vent at the upstream end, provided certain conditions are met.
What is the maximum developed length of a trap arm between the trap weir and the vent pipe for a 1-1/2 inch drain?
Answer: 5 feet
Per IPC, the maximum trap arm length for a 1-1/2 inch pipe is 5 feet from the trap weir to the vent.
In designing a water distribution system using the fixture unit method, a residential lavatory is assigned how many water supply fixture units (WSFU)?
Answer: 1 WSFU
A residential lavatory is assigned 1 WSFU per the IPC demand load tables for sizing supply piping.
A pressure-reducing valve (PRV) should be installed when the municipal supply pressure exceeds which threshold per the IPC?
Answer: 80 psi
The IPC requires a PRV when supply pressure exceeds 80 psi to protect fixtures and piping from over-pressurization.