Autoclaves and steam sterilizers for practices and clinics - melag
https://www.melag.com › products › steam-sterilizers
***Ventilation*** / exhaust phase: Upon completion of the sterilization program, autoclaves using Class B or Class S programs draw ambient air into the steam ...

ANSI/AAMI ST77:2013/(R)2018
Containment devices for reusable medical device sterilization
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3.43 volume-to-vent (V-to-V) ratio: Ratio (V-to-V) of the interior container volume to the surface perforation area.
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NOTE—The V-to-V ratio may be one of the metrics used in defining a worst-case challenge for a family of containment devices. This ratio is defined as the interior volume of the sterilization container divided by the total cross-section area of the perforated vent holes. V-to-V ratio influence to the container system is influenced by the sterilization methodology. For example, a dynamic air removal system will have lesser V-to-V ratio concerns compared to a gravity displacement system. When the V-to-V ratio is critical to the container system under consideration, a higher V-to-V ratio presents a more difficult challenge to achieve the desired lethality performance and should be assessed.

For example, for a particular container volume, an increase in the cross-section area of the perforations allows easier ingress and egress of the sterilant during the processing cycle. Conversely, for a given perforation ratio—as interior volume is increased, it is more difficult to fill and empty this volume through the same vent area. The worst-case V-to-V ratio does not necessarily coincide with the largest container by volume or footprint. A full-size container with two arrays of perforations may have a lower V-to-V ratio (i.e., easier to empty and fill the internal volume) than a mid- or three-quarter size container with only one array of perforated holes. Similarly, a full-size container with a solid bottom will have a higher V-to-V ratio than the same full-size container with a perforated bottom, resulting in a more difficult challenge to achieve the desired lethality performance.
https://webstore.ansi.org/preview-pages/AAMI/preview_ST77_20...

3M™ Steri-Vac™ Sterilizer / Aerator GS Series – Operator’s Manual
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If the packaging is not specified by the endoscope manufacturer, best practices for packaging of endoscopes for EO sterilization include metal baskets and disposable sterilization wraps due to the smallest Volume to Vent (V-to-V) ratio. The V-to-V ratio is a measurement of the ability for the sterilant to flow into and out of the sterilization container or packaging. This ratio is defined as the interior volume of the sterilization container divided by the total cross-sectional area of the perforated vent holes. Metal baskets and disposable sterilization wraps or some brands of plastic trays wrapped in disposable sterilization wraps have a relatively small Volume to Vent (V-to-V) ratio.
https://multimedia.3m.com/mws/media/1072490O/3m-steri-vac-st...