| 摘要 |
<p>The device (10) has an aeration unit (146) exposed to the ambient air. The aeration unit communicates with a downstream portion in an open configuration of the aeration unit, and does not communicate with the downstream portion in a closed configuration of the aeration unit. The downstream portion is subjected to primary pressure irrespective of open or closed state of a tapping unit. The aeration unit is passed from the open configuration to the closed configuration when the primary pressure is greater than atmospheric pressure.</p> |
