Final answer:
A mop sink must be equipped with a backflow prevention device to prevent contaminated water from flowing back into the potable water supply. Air gaps are also used in plumbing to provide a physical separation to prevent back-siphonage. Aerators in sink drains can improve water flow but are distinct from backflow prevention.
Step-by-step explanation:
In order for a hose to be connected to a mop sink faucet, the mop sink must be equipped with a backflow prevention device. This is critical to prevent cross-contamination of the potable water supply. A backflow prevention device ensures that water cannot flow back into the public water system, which could carry contaminants and pollutants from the dirty water in the sink back to the clean water supply.
The presence of air-filled tubes near water faucets, often referred to as air gaps, is another measure for protecting the water supply. These air gaps help to prevent back-siphonage by ensuring there is no direct connection between the faucet and a potential source of contamination. In case of a pressure drop, the air gap breaks the siphon effect, preventing contaminated water from being drawn into the clean water system.
Another common plumbing feature to speed the flow of water is the aerator attached to the tailpiece of the sink. Aerators introduce air into the water stream which can break the stream into smaller droplets. This is not to be confused with a backflow prevention device, although aerators may have an anti-siphon design to help prevent backflow.