What is the purpose of a backflow preventer?

The primary function of a backflow preventer is to prevent contaminated water from flowing back into the clean water supply. This device is crucial for maintaining water quality and protecting public health. When there is a change in pressure in the water supply system—such as a drop in pressure due to a pipe break or repair—backflow can occur, allowing potentially harmful substances from various sources, like industrial facilities or plumbing systems, to enter the potable water system.

By using a backflow preventer, the flow of water is directed in one direction only, ensuring that if there is a negative pressure situation, contaminated water does not reverse flow into the clean water supply. This is particularly important in residential, commercial, and industrial applications where water contamination could have serious health implications.

The other options, such as increasing water pressure, measuring water flow, or regulating water temperature, do not relate to the role of a backflow preventer and address different aspects of water system management.