抗爆閥用于保護避難所，例如防輻射避難所或掩體，使其免受外部氣壓突然變化的影響。核武器會產生沖擊波，它可能會產生超過一個大氣壓（約 1 巴）甚至距爆炸點數公里的突然壓力變化。沖擊波過去后，隨之而來的是突然的負壓。 如果這種壓力波進入避難所，它們可能會對居住者和設備造成重大傷害。排氣閥放置在進氣/排氣管道中，該閥保持正常打開狀態，但在任一方向施加強壓力時自動關閉。防爆閥以相同的方式工作，與防爆閥相關或相同，但前者通常用于描述爆炸緩解裝置，更多的是傳統爆炸事件。

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.