Pressurized Vacuum Breaker is described as:

Pressurized Vacuum Breaker is described as:

• A. A device that relies on atmospheric air to break back siphon.
• B. A device with two check valves and a differential valve.
• C. A device that uses continuous water pressure to prevent backflow when pressure is lost.
• D. A simple cap that covers the fill opening.

Answer: (C)

A pressurized vacuum breaker works by using the system’s own pressure to keep its valve(s) closed and prevent backflow. When the water supply is running normally, continuous pressure keeps the internal valve(s) engaged, so water can’t flow back toward the source. If that pressure is lost—say the pump stops or a line is damaged—the device vents to the atmosphere and air is admitted, which breaks any siphon and stops contaminated water from being drawn back into the supply. This description matches the idea that it prevents backflow by relying on continuous water pressure to hold back flow, but will release air to break the siphon if pressure drops. It’s different from an atmospheric vacuum breaker, which relies on atmospheric air alone, and different from backflow preventers with multiple check valves and a differential valve.

A pressurized vacuum breaker works by using the system’s own pressure to keep its valve(s) closed and prevent backflow. When the water supply is running normally, continuous pressure keeps the internal valve(s) engaged, so water can’t flow back toward the source. If that pressure is lost—say the pump stops or a line is damaged—the device vents to the atmosphere and air is admitted, which breaks any siphon and stops contaminated water from being drawn back into the supply. This description matches the idea that it prevents backflow by relying on continuous water pressure to hold back flow, but will release air to break the siphon if pressure drops. It’s different from an atmospheric vacuum breaker, which relies on atmospheric air alone, and different from backflow preventers with multiple check valves and a differential valve.