The function of a relief valve is to:

The primary function of a relief valve is to prevent system overload conditions. Relief valves are safety devices designed to protect pressure vessels, piping systems, and other equipment from excessive pressure buildup. When the pressure in a system exceeds a certain threshold, the relief valve opens to allow excess pressure to escape, thereby preventing potential damage or failure of the system.

Maintaining a constant flow rate and controlling system temperature can be important in certain applications, but those functions are typically addressed by different types of valves or control mechanisms. The relief valve's main job is specifically to act as a safeguard against overpressurization, making it crucial for operational safety and reliability in hydraulic and pneumatic systems.