What type of valves must be provided for tempering water supplied to the potable hot water system?

Mixing valves are specifically designed to blend hot and cold water in order to provide water at a consistent safe temperature, which is essential for a potable hot water system. These valves help to prevent scalding by regulating the water temperature as it enters the system, ensuring that the delivered water is at a safe level for use.

In the context of the North Carolina Mechanical Code, the requirement for mixing valves is particularly important to maintain not only safety but also to enhance comfort for users. By mixing the water appropriately, these valves reduce the risk of exposure to excessively hot water, aligning with the safety standards mandated in plumbing and mechanical codes.

Other types of valves, such as temperature-controlled valves or safety valves, may serve important functions in different contexts, but they do not specifically regulate the mixture of hot and cold water to achieve the desired temperate output for potable systems. Pressure valves serve to manage water pressure rather than temperature. Therefore, mixing valves are the most appropriate choice for managing the temperature of water supplied to a potable hot water system.