| 摘要 |
The present invention relates to a valve device (1) for a ventilation installation. The valve device (1) comprises a vent surface (4) that is equipped with a plurality of vent apertures (5) and a slide valve (6) comprising a slide valve plate (7) equipped with a plurality of slide valve apertures (8). The valve plate formed such that it can be varied between taking a first position (I) at which the vent apertures (5) are covered by the slide valve plate (7), and taking a second position (II) at which at least some vent apertures (5) have surfaces that overlap with some slide valve apertures (8) such that an air flow is permitted through the valve device (1). The valve device (1) is designed such that when the slide valve plate (7) is positioned on that side of the vent surface (4) that normally has a relatively higher pressure, the high pressure side (9), than the other side, the low pressure side (10). The slide valve plate (7) is formed such that the force from the pressure difference between the high pressure side (9) and the low pressure side (10) is sufficient to retain the slide valve plate in its place at the vent surface (4) when it is in the first, closed position (I). |
