| 摘要 |
<p>The device (1) has a non-return valve (3) mounted in an exhaust duct (2) in a rotatable manner, and a locking device (5) cooperating with the valve. The valve is pivoted in an exhaust air direction from a closed position into an open position due to working pressure difference against a surrounding pressure. The locking device releases the valve due to pressure rise in the duct opposite to the surrounding pressure. The locking device locks the valve in the closed position due to pressure loss in the duct against an automatic opening.</p> |
