A pressure relief valve is a safety device designed to control or limit the pressure in a system. It automatically releases excess pressure to prevent equipment damage or failure. These valves are commonly used in various applications, including boilers, piping systems, and pressure vessels. When the pressure in a system exceeds a predetermined level, the valve opens, allowing fluid to escape. This action helps maintain safe operating conditions and protects against potential hazards, such as explosions or leaks. Regular maintenance of pressure relief valves is essential to ensure their proper functioning and reliability.