What is a common example of a backflow prevention device?

A check valve serves as a common example of a backflow prevention device due to its fundamental role in preventing the reverse flow of water within irrigation systems. When water moves in the intended direction, the check valve opens, allowing flow. However, if there is a change in pressure or a backflow situation, the valve closes, effectively blocking any backflow from contaminating the water supply. This mechanism is crucial in protecting potable water sources from potential pollutants that may be drawn back through the system.

In contrast, devices like pressure relief valves, flow meters, and filter traps serve different purposes within an irrigation system. A pressure relief valve is designed to release excess pressure, ensuring system components are not damaged. A flow meter measures the volume of water flowing through the system, and a filter trap helps eliminate sediment or debris from the water, thereby improving water quality. These devices do not provide backflow prevention and therefore do not fulfill the specific function that a check valve does in maintaining the integrity of water supply systems.