| 摘要 |
<p>A frame for receiving a flood door includes a lower cross-member (7). The lower cross-member has a recess (9) in an upper face thereof and an external face. At least one non-return valve (11) is provided in the cross-member and communicates between the recess and the external face. The non-return valve is adapted to prevent entry of flood water through the frame in flood conditions and to allow escape of water from the recess in the absence of flood conditions.</p> |
