What is the primary purpose of a backflow preventer?

The primary purpose of a backflow preventer is to prevent contamination of potable water. Backflow occurs when there is a reversal of flow in a plumbing system, which can allow contaminated water from non-potable sources to flow back into the clean drinking water supply. This can happen due to various reasons, such as a drop in water pressure or a change in the water supply system.

A backflow preventer acts as a safeguard by ensuring that water flows in one direction only. This device is typically installed in areas where there is a risk of backflow, protecting the public water supply from harmful substances and pollutants. By maintaining the integrity of the potable water system, backflow preventers play a crucial role in public health and safety.

Other options such as increasing water pressure, regulating water temperature, and filtering debris do not directly address the specific function of preventing contamination in potable water, which is the key reason for the existence of backflow preventers in plumbing systems.