What type of backflow prevention is needed for pedicure chairs with water inlets below the flood level rim?

For pedicure chairs with water inlets located below the flood level rim, a reduced pressure principle backflow preventer is required. This type of backflow prevention device is designed to protect the potable water supply from contamination as it effectively prevents backflow due to both backpressure and back siphonage.

In situations where water inlets are below the flood level rim, there is a higher risk that wastewater could backflow into the system, especially if there is a sudden change in pressure. The reduced pressure principle backflow preventer operates with two check valves in series and is separated from the water supply by a vent that remains open to the atmosphere, ensuring that any backflow is diverted away from the potable water system.

Air gaps are highly effective at preventing backflow but are not feasible in most practical applications for pedicure chairs due to space constraints. Double check valves are suitable for moderate risk situations and do not provide the same level of protection against backpressure as a reduced pressure backflow preventer. Vacuum breakers, while useful for preventing back siphonage, are typically not designed for continuous pressure systems, making them less applicable in this context.

Thus, a reduced pressure principle backflow preventer is the most suitable and effective device for ensuring the safety of