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
Under the IPC, what is the maximum allowable working pressure for a residential cold water distribution system inside a building?
Answer: 80 psi
The IPC limits residential water supply pressure to a maximum of 80 psi; pressures above this require a pressure-reducing valve.
Cross-linked polyethylene (PEX) tubing used in water supply systems must comply with which standard?
Answer: ASTM F876 / F877
ASTM F876 covers PEX tubing dimensions and ASTM F877 covers fittings; both are referenced by the IPC for PEX water supply installations.
In fixture unit calculations, a 1-inch meter service connection has a maximum capacity of approximately how many WSFU?
Answer: 100 WSFU
Per IPC Table E103.3(2), a 1-inch meter/service generally serves up to approximately 100 WSFU for typical mixed-use conditions.
Which phenomenon causes 'water hammer' in plumbing systems?
Answer: Sudden velocity change when a quick-closing valve shuts
Water hammer (hydraulic shock) results from the rapid deceleration of a water column when a quick-closing valve closes, converting kinetic energy into a pressure wave.
What is the function of a mixing valve in a domestic hot water distribution system for healthcare or care facilities?
Answer: To blend hot and cold water for precise temperature control at the point of use
Thermostatic mixing valves blend stored high-temperature water (140°F+ for Legionella control) with cold water to deliver safe scald-protected temperatures (typically 110–120°F) at the point of use.
When calculating the available pressure for pipe sizing, which of the following must be subtracted from the street main pressure?
Answer: All losses including meter, elevation, fittings, and pipe friction
Available pressure for design equals street pressure minus all losses: elevation head, meter loss, pipe friction, valve losses, and fittings — to ensure adequate pressure at the critical fixture.
What distinguishes a Type K copper tube from a Type L copper tube?
Answer: Type K has a thicker wall and is used for underground service; Type L is for interior supply
Type K copper has the thickest wall of the three types and is suitable for underground and critical service applications; Type L has a medium wall thickness used for interior water supply.