A safety valve is a mechanical device designed to protect equipment, systems, and personnel by automatically releasing excess pressure from a system when it exceeds a preset limit. It prevents damage or catastrophic failure caused by overpressure, which can occur in boilers, pressure vessels, pipelines, and other pressurized systems. Safety valves are critical for ensuring the safe operation of industrial processes and complying with safety regulations.

A safety valve functions by automatically opening when a system's pressure surpasses a preset threshold. Usually, a spring-loaded mechanism keeps the valve closed in usual circumstances. When the pressure reaches the predetermined limit, the force of the pressure acts against the spring tension, opening the valve and releasing the excess pressure. The valve is closed by the spring when the pressure reaches a safe level again.