Which component is present in a hose connection to provide high hazard protection?

In a hose connection, the component that provides high hazard protection is the presence of two check valves. This arrangement is essential because high hazard systems, which may involve the use of hazardous substances, require robust measures to prevent any backflow of contaminated water into the potable water supply.

Two check valves create a physical barrier that significantly reduces the likelihood of backflow. If one check valve were to fail, the second check valve acts as a safeguard, ensuring that contaminants cannot enter back into the drinking water system. This redundancy is a critical safety feature when dealing with potential cross-connections in environments where hazardous chemicals or contaminants are present.

Therefore, having two check valves is mandated in many plumbing codes and standards to ensure compliance and enhance public health protection. The other components listed, while useful in various contexts, do not provide the same level of high hazard protection as the dual check valve setup does.