safety valve

A safety valve is a crucial device designed to prevent excessive pressure buildup in systems like steam boilers. It functions by automatically opening when the internal pressure reaches a predetermined level, releasing gas or liquid in a controlled manner. This controlled release acts as an outlet, preventing potential damage or dangerous situations.1

Safety valves are typically of the poppet type and are held closed by a weighted lever or a spring strong enough to maintain closure until the critical pressure is reached. In some applications, like boilers, a related device called a safety plug, made of fusible metal, can also release steam if excessive pressure causes it to overheat. Beyond mechanical applications, the term "safety valve" can also metaphorically refer to anything that relieves pent-up energy, emotion, or the pressure of overcrowding.231