安裝在泵出口或分配管路中，用於排除管道內積聚的大量空氣或排出管道上部積聚的少量空氣產生大氣，

以提高使用效率 管道和泵的連接和安裝在管道中。

當出現負壓時，閥門迅速吸入外界空氣，保護管道免受負壓損壞。

It is installed at the pump outlet or in the distribution line to remove a large amount of air accumulated in the pipeline or to discharge a small amount of air accumulated

in the higher part of the pipeline to produce atmosphere, so as to improve the service efficiency of the pipeline and pump and to be in­stalled in the pipeline .

When negative pressure occurs, the valve quickly sucks in outside air to protect the pipeline from damage caused by negative pressure.