If the water inlet for a pedicure chair is below the flush level rim or is equipped with a spray hose, it shall require a backflow preventor on both hot and cold water lines of which type?

• A. Atmospheric vacuum breaker
• B. Double check valve
• C. Reduced pressure principle
• D. None

Answer: (C)

Backflow protection is essential whenever a fixture could pull non-potable water back into the drinking water supply. When a pedicure chair’s water inlet is below the flush rim or equipped with a spray hose, conditions can change pressure and create a pathway for contamination to be drawn back into the supply. In this high-hazard cross-connection, the most protective remedy is a reduced pressure principle backflow preventer, installed on both hot and cold water lines. This type uses two check valves plus a relief port to vent water if backflow conditions occur, providing reliable protection against both backpressure and backsiphonage. Placing it on both hot and cold lines ensures no route is left vulnerable if pressure shifts happen on either side. Other devices, such as atmospheric vacuum breakers, don’t offer the same level of protection for hot lines or for situations with spray hoses, and a double-check valve doesn’t meet the higher protection needed here.