| 摘要 |
A ventilator (22) includes elongate sections (24, 30) at least partly defining an upper control chamber (112) and a lower main flow chamber (40). The chambers (112, 40) may be isolated from one another by a seal (50) when a closure member (44) of the ventilator is closed to avoid water leakage into end caps (34) of the ventilator. |
