Gas-permeable, liquid-impermeable vent cover

摘要

A flexible, insertable vent cover is formed from a flexible, resilient material. The cover has a through passageway; a gas-permeable, liquid-impermeable membrane traversing the passageway; a diaphragm valve covering the membrane; and an annular securing ring that maintains the valve in a protective position with respect to the membrane in order to protect the membrane from immersion in or impingement by liquid.