Abstract: High-outflow one-way pressure relief valves with structure unexpectedly providing high-outflow gas evacuation from a package are disclosed. Pressure relief valves of the types described herein may be applied to a product package with a flexible wall or walls, for example a package containing food products, to allow gas to escape from the package while preventing entry of ambient air into the package. The valve structure provides for a high-outflow valve which opens at a low pressure differential between pressure within the package and pressure outside the package to allow gas existent in the package to be rapidly evacuated from the package while preventing air inflow into the package. The valve enables a package to be rapidly compacted for efficient stacking, storing, palletizing, transporting, displaying of the packaged goods at a point of sale, or any other purpose for which efficient package size is wanted while also preserving and maintaining the quality of the packaged product.

Abstract: One-way pressure relief valves having a plural-part dry strap are disclosed. One-way pressure relief valves may be applied to a product package to evacuate gas from the package. In embodiments, the plural-part dry strap comprises overlapping dry strap parts which impart improved operation to the valve.