| 摘要 |
A vent comprises a vent body (1) having at least one air flow channel through the body between a front face and a rear face (2) of the body. At least one float controlled flap valve (13) is pivotably mounted within the body, the or each valve having a first, normal position in which air is permitted to flow through an air flow channel and a second position in which the valve pivots in the presence of water to seal the air flow channel. |
