Water Supply & Distribution Systems Flashcards
7 cards from real CPD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Water Supply & Distribution Systems flashcards as text
When sizing a cold water branch serving a bathroom group (lavatory, water closet, bathtub), what WSFU value is commonly assigned per the IPC?
Answer: 5 WSFU
The IPC assigns 5 WSFU to a full bathroom group (lavatory, water closet, and bathtub/shower) for sizing purposes.
Which formula relates head loss to flow velocity, pipe diameter, and friction factor in water distribution design?
Answer: Darcy-Weisbach equation
The Darcy-Weisbach equation calculates head loss due to friction as a function of the Darcy friction factor, pipe length, diameter, and flow velocity.
What is the primary purpose of a pressure-reducing valve (PRV) in a water supply system?
Answer: To reduce high street pressure to a safe working range
A PRV reduces high incoming street pressure (often 80–150 psi) to a safe, code-compliant working pressure typically set at 60–80 psi.
Galvanic corrosion in a water supply system is most likely to occur when:
Answer: Dissimilar metals are connected without dielectric isolation
Galvanic corrosion occurs at the junction of dissimilar metals in the presence of an electrolyte (water), driving electrochemical current that degrades the anodic metal.
For a booster pump system in a high-rise, the pump is typically selected to provide adequate pressure at the:
Answer: Most remote and highest fixture in the zone
Booster pumps must overcome both elevation head and pipe friction to deliver adequate pressure at the most hydraulically remote and elevated fixture.
What does a 'demand factor' account for in water supply system design?
Answer: The probability that not all fixtures will operate simultaneously
A demand factor (or diversity factor) acknowledges that in any system, all fixtures are statistically unlikely to operate at full flow simultaneously.
Which type of water hammer arrestor installation location is most effective per PDI standards?
Answer: Within 6 pipe diameters of the quick-closing valve it protects
PDI standards recommend installing water hammer arrestors as close as possible to the quick-closing valve (within 6 pipe diameters) to most effectively absorb the pressure surge.