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Vent & Process Gas Filtration

to Protect Product Quality

Preventing the contamination of liquid ingredients, intermediate solutions or process water while they are in a tank is critical to the quality of your finished products. For more on how filters help protect those liquids, read below, or go to the product selection table at the bottom of this page for tank vent filter options.

Adding a liquid to a tank forces air out, just as emptying a tank draws outside air into it. Since the air around tanks is full of airborne bacteria, mold spores, dust and other contaminants, filters are used to prevent those contaminants from reaching the liquid.

filtration in juice production diagram

Tank Vent Filters

In most systems, the tanks used are sealed. That makes sizing a vent filter system critical. A filter system that overly restricts the flow of air in and out of the tank may result in the tank being over-pressurized (possible seal damage) or a vacuum being created in the tank (potential tank collapse). Critical Process Filtration has years of experience sizing filter systems and can help you design your system to avoid such issues.

Filtering Process Gases

Normal atmosphere is sometimes not allowed to contact the product either in process or in the final package. This is done if oxygen might promote the growth of undesired organisms or cause oxidation of the product that affects flavor quality. Normal air may be replaced in tanks and/or containers with process gases – usually nitrogen, carbon dioxide or a combination. As the containers are filled, a process gas “blanket” is injected into the container to displace air before container closure.

All tank and process gas filtration is done using hydrophobic filter membranes. Being hydrophobic, the membrane prevents water droplets from collecting on and wetting the membrane, which would block the flow of air or gas. This could lead to tank failure or prevent air from being displaced in containers and jeopardize product quality. Filters with 0.22µm pore sizes are usually used because of their ability to block bacteria.

Custom systems are designed for new applications and to solve challenges in existing processes. Critical Process Filtration will work with you to design, build and install a cost-effective system that delivers the results you need. Contact us or visit our custom filtration systems page for more information.

Application Summaries

Critical Process Filtration has multiple hydrophobic filter options for protecting tank contents and filtering process gases. To read more about the ways you can protect your product from airborne contaminants, click on one of the links below. Critical Process Filtration has created some short explanations of how filters help protect tank contents.

Product Table

Critical Process Filtration has hydrophobic filter options to meet various contamination control needs. Whether for control of dust and visible particles or to prevent bacterial contamination, the filters you need are available from Critical Process Filtration. The table below shows those options with links to more detailed data on the filters.

Media Code

Filter Media

Filter Grade

Cartridge Datasheet

Capsule Datasheet

Disc Filter Datasheet

Pore Sizes Available (µm)



Hydrophobic Polyvinylidene fluoride Membrane

Food & Beverage

Acrobat Document

Acrobat Document

Acrobat Document

0.22, 0.45, 0.65, 0.85, 1.0

High capacity hydrophobic membrane for economical bacteria control in vent filtration


PTFE Membrane


Acrobat Document

Acrobat Document

Acrobat Document

0.1, 0.22, 0.45, 1.0

Highly hydrophobic with superior air flow rates for vent filtration


High-Temperature PTFE Membrane


Acrobat Document



0.1, 0.22

Highly hydrophobic and constructed using high temperature materials for systems subjected to frequent heat sanitizations. Superior flow rates for vent filtration

To estimate the number of filters you will need for your application, use our unique sizing tools.

Contact Critical Process Filtration if you have any questions, wish to discuss a specific application or want to learn more about any of our Products and Services. We look forward to hearing from you!