Core TradesQuestion 187 of 700
A common device required on an outdoor hose bibb to prevent contaminated water from being drawn back into the potable supply is a:
a.Pressure-reducing valve
b.Thermostatic mixing valve
c.Water hammer arrestor
d.Hose-bibb (atmospheric) vacuum breaker
Explanation
A hose-bibb vacuum breaker admits air to break any siphon so garden or chemical water cannot be back-siphoned into the potable system. A pressure-reducing valve controls pressure, a water hammer arrestor cushions surges, and a mixing valve blends hot and cold water, none of which prevents backflow.
Law Reference: 2025 CA Plumbing Code, Chapter 6 (Backflow Protection)Practice all 700 questions free — no signup required.
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