| 摘要 |
<p>Rectangular or circular vent apparatus for protecting a confined space ha ving a vent aperture for relief of an overpressure condition is provided wit h each including vent structure having a vent unit adapted to be positioned over the vent aperture in normal closing relationship thereto. Each vent uni t preferably includes at least one spring steel panel provided with a movabl e pressure relief portion having an initial position extending across the ve nt aperture. A backstop is provided for arresting the degree of movement of the spring steel panel, that absorbs kinetic energy of opening of the spring steel panel, and that assures return of the relief portion of the spring st eel panel in substantially its original shape to a selected opening position when a predetermined overpressure is applied against the relief portion of the vent unit. A line of weakness comprising a series of end-to-end slits de fines the movable pressure relief portion of each spring steel panel. A synt hetic resin sheet covers the slits of each line of weakness. Alternatively, the vent unit may have spring steel leaves positioned against a metal sheet provided with a relief portion and normally positioned in closing relationsh ip to the vent aperture. The spring steel panel and the spring steel leaves have a sufficient modulus of resilience and elasticity to cause the relief p ortion of the spring steel panel or the metal sheet to return to their respe ctive initial positions from the open positions thereof upon relief of the o verpressure condition in the confined space.</p> |
