Final answer:
An air gap is a form of backflow prevention used in plumbing systems to prevent contamination of drinking water. It creates a physical barrier between the clean water supply and the wastewater, preventing the backflow of wastewater. Air gaps are commonly used in residential, commercial, and industrial settings to protect public health.
Step-by-step explanation:
An air gap is a form of backflow prevention that is commonly used in plumbing systems to prevent the contamination of drinking water. It is created by having an open vertical space between the outlet of a plumbing fixture and the flood level rim of a connected receiving vessel, such as a sink or a bathtub. This air gap acts as a physical barrier that prevents the backflow of wastewater into the clean water supply.
Air gaps are effective in preventing backflow because they rely on the natural pressure difference between the clean water supply and the connected vessel. If there is a sudden decrease in pressure in the clean water supply, such as when a pipe bursts or there is a drop in water pressure due to high demand, the air gap will ensure that the wastewater does not flow back into the clean water supply. It is, therefore, an important safety measure to protect public health.
It is worth noting that while air gaps are commonly used in residential, commercial, and industrial settings, their use is not limited to any specific water source or industries. It is a universal backflow prevention method that can be implemented wherever there is a risk of cross-contamination between wastewater and the clean water supply.