A double check valve protects the potable water supply from what type of hazard?

A double check valve is specifically designed to protect the potable water supply from low hazard backpressure or backsiphonage. This type of valve consists of two independently acting check valves, which prevent the reverse flow of water into the system.

Low hazard situations are typically those that may cause contamination but do not represent a significant danger to public health. Therefore, the double check valve is an ideal choice in scenarios where the potential for backpressure or backsiphonage exists but does not involve toxic or hazardous materials.

In contrast, high hazard backpressure would require a different type of protective device, such as a reduced pressure zone (RPZ) assembly. Environmental contamination usually necessitates more stringent control than a double check valve can provide, and high-pressure surges involve physical conditions that do not pertain to backflow prevention mechanisms. Each of these scenarios requires specific protections that address the level of risk they present, affirming the suitability of the double check valve for managing low hazard concerns effectively.