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
A sovent single-stack system eliminates conventional venting through the use of which key component?
Answer: An aerator fitting at each story and a deaerator fitting at the base
The sovent system uses an aerator fitting at each floor connection to introduce air and prevent siphonage, and a deaerator at the base to separate air before it enters the building drain.
In designing a recirculating hot water system for a large commercial building, the recirculation pump is sized to overcome which primary system resistance?
Answer: The friction losses through the longest circulation loop
The recirculation pump must overcome the friction head loss around the complete recirculation loop — the longer the loop, the greater the required pump head.
Under the IPC, what is the maximum number of fixtures that may drain into a 3-inch horizontal branch drain at a 1/4-inch per foot slope?
Answer: 20 drainage fixture units
A 3-inch horizontal branch at 1/4-inch per foot slope has a maximum capacity of 20 drainage fixture units per the IPC drainage sizing tables.
When a plumbing system design includes a reduced-pressure zone (RPZ) backflow preventer, where must it be installed relative to the protected premises?
Answer: At the service entrance before any branch connections to the premises
An RPZ must be installed at the point of service entry before any branch connections to ensure complete protection of the downstream system.
Which design approach is used to prevent thermal expansion pressure buildup in a closed hot water system that includes a backflow preventer on the cold supply?
Answer: Installing a thermal expansion tank on the cold water supply side
A thermal expansion tank absorbs the increased volume of heated water, preventing dangerous pressure rise in a closed system that cannot expand back through the meter.
In gravity-fed rainwater harvesting system design, collected rainwater used for toilet flushing must be treated to which standard before distribution?
Answer: Non-potable standards with turbidity below 2 NTU and coliform-free
Most codes require harvested rainwater for toilet flushing to be filtered and disinfected to achieve less than 2 NTU turbidity and be free of coliform bacteria.
What is the minimum required vent stack size when a drainage stack serves more than 10 branch intervals in a building?
Answer: One-half the diameter of the drainage stack it serves
Per IPC, the vent stack for a drainage stack serving more than 10 branch intervals must be at least one-half the diameter of the drainage stack.