What can be added to piping to achieve a reduced temperature on the secondary circuit?

A three-way mixing valve is designed to control the temperature of water in a secondary circuit by blending hot and cold water. In a typical application, this valve allows for the mixing of water at different temperatures to achieve the desired output temperature for the secondary circuit. It works by adjusting the flow of hot water from the primary circuit and cold water from the return line, providing precise control over the temperature delivered to the system.

This is an essential component in systems that require stable temperatures, such as hydronic heating or hot water systems, ensuring efficient operation and comfort. By allowing varying amounts of hot and cold water to mix, the three-way mixing valve effectively reduces the temperature on the secondary circuit as needed.

The other options, while useful in different contexts, do not provide the capability to directly manage temperature in the same way. A manual valve controls flow but does not mix temperatures; a pressure relief valve is primarily for safety, regulating pressure instead of temperature; and a flow meter is used to measure the flow rate but does not influence the water’s temperature.