Where should a pressure relief valve be installed in a hydronic piping system with reduced pressure?

A pressure relief valve is a critical safety component in hydronic piping systems, and its correct installation is essential for preventing potential plumbing hazards due to overpressure. The valve should be installed on the low-pressure side of the system because its primary function is to relieve excess pressure that can build up during operation, which can occur due to thermal expansion, pump cycling, or other pressure fluctuations.

Installing the pressure relief valve on the low-pressure side allows it to effectively monitor and respond to the conditions that could lead to unwanted pressure increases within the system. If the valve were on the high-pressure side, it would not function adequately in its role since it would not relieve pressure effectively when the system experiences excess pressure.

Furthermore, placing the valve at any joint in the system may not provide accurate pressure readings or efficient operation, as the water's behavior and pressure dynamics in different sections of piping can vary. Also, placing it immediately before the pump might not allow it to function as intended under various operating conditions, particularly if there are fluctuations in pressure due to the pump activity. Therefore, the specific choice of the low-pressure side ensures optimal safety and performance of the hydronic system.