Temperature and pressure relief valves are safety devices designed to protect hot water systems from excessive temperature and pressure buildup. They release excess pressure or temperature to prevent the system from rupturing or causing damage.

Temperature relief valves use a thermal actuator to sense when the water temperature exceeds a set point. When the temperature threshold is reached, the valve opens to release hot water and reduce the temperature. Pressure relief valves, on the other hand, use a piston or diaphragm to sense and release excess pressure when it exceeds a specified limit.

There are various types of temperature and pressure relief valves available, including: Watts TPR Steam Relief Valves, Watts TPR Water Relief Valves, Watts TPR Low Lead Relief Valves, and Watts TPR Hi-Capacity Relief Valves. Each type is designed for specific applications and temperature/pressure ranges.

Selecting the appropriate temperature and pressure relief valve is crucial for system safety. Consider factors such as the maximum temperature and pressure the system can withstand, the flow rate required, and the type of system (closed or open). Consulting a professional plumber or referring to the manufacturer's specifications is recommended to determine the best valve for your needs.