What is the primary purpose of a backflow preventer?

The primary purpose of a backflow preventer is to prevent water contamination. A backflow preventer is a crucial device in plumbing systems that safeguards potable water supplies from contamination by ensuring that water flows in one direction only. This is especially important in situations where there is a risk that water from non-potable sources could flow back into the clean water supply due to changes in water pressure or flow direction. By preventing backflow, these devices protect public health by ensuring that drinking water remains free from harmful substances that could enter through reverse flow.

Regulating water flow, lowering water pressure, or storing excess water are not the main functions of a backflow preventer; rather, they address different aspects of water management and plumbing systems.