抗爆阀用于保护避难所，例如防辐射避难所或掩体，使其免受外部气压突然变化的影响。核武器会产生冲击波，它可能会产生超过一个大气压（约 1 巴）甚至距爆炸点数公里的突然压力变化。冲击波过去后，随之而来的是突然的负压。 如果这种压力波进入避难所，它们可能会对居住者和设备造成重大伤害。排气阀放置在进气/排气管道中，该阀保持正常打开状态，但在任一方向施加强压力时自动关闭。防爆阀以相同的方式工作，与防爆阀相关或相同，但前者通常用于描述爆炸缓解装置，更多的是传统爆炸事件。

A blast valve is used to protect a shelter, such as a fallout shelter or bunker, from the effects of sudden outside air pressure changes. A nuclear weapon creates a shock wave, which may produce sudden pressure changes of more than an atmosphere (about 1 bar) even several kilometres from the detonation point. After the shock wave passes, a sudden negative pressure follows.

If such pressure waves enter a shelter, they will likely do substantial harm to occupants and equipment. A blast valve is placed in air intake/exhaust pipes, that remains open normally, but automatically closes when strong pressure is applied in either direction. Blast dampers operate in the same fashion and are related or identical to blast valves, the former name however is generally used to describe blast mitigation devices, for more, conventional explosive events.