Process Cartridge Filters for Gas and Steam Applications in the Dairy and Food Industry

Modern cartridge filters — including coalescing filters, pleated glass fibre sterile gas filters, and hydrophobic membrane filters — ensure that these utility streams remain clean, sterile, and compliant.

Why Filtration of Gases and Steam Matters

Without proper filtration, gases and steam can carry:

• Microorganisms
• Particulate contamination
• Oil aerosols from compressors
• Moisture or condensate
• Rust or scale from pipework (steam)

These contaminants can compromise product safety, shorten shelf life, and damage equipment. Proper filtration protects both the process and the end product.

Gas Filtration in Dairy and Food Production

Process gases are used for:

• Tank venting and blanketing
• Packaging and filling machines
• Pneumatic systems
• Aeration, sparging, carbonation
• Powder conveying and hopper pressurisation

These applications require validated sterile gas and the correct filtration sequence.

Two-Stage Gas Filtration System

Unlike older systems that included an “intermediate pleated filter,” modern hygienic design focuses on two essential stages:

1. Coalescing Prefiltration (Mandatory)

Removes condensate, aerosols, and high particulate loading

Coalescing filters are critical because they:

• Remove oil aerosols, liquid condensate, and fine particulates
• Protect the final sterile gas filter from premature blockage
• Deliver the required cleanliness for reliable sterile gas filtration

Why pleated polypropylene cannot replace coalescing filters

Some end users attempt to use pleated polypropylene cartridges instead of true coalescing elements. However:

• Pleated PP does not reliably remove aerosols
• Pleated PP does not separate or drain condensate
• Fine droplets pass straight through to the sterile filter, greatly reducing its service life

Pleated PP cartridges may be used as an optional particulate filter in dry nitrogen or CO₂ systems but are not suitable as the primary protective stage for sterile gas.

Only coalescing elements provide the mechanical structure and media design needed to remove aerosols and liquid contaminants from compressed gases.

2. Final Sterile Gas Filtration (Validated Sterility)

At this stage, processors can choose between two fully validated technologies:

Option A: Pleated Glass Fibre Sterile Gas Cartridges

Validated sterile gas filtration with exceptional flow and low differential pressure

Pleated glass fibre sterile filters now provide validated sterile gas under all operating conditions.

Their advantages include:

Extremely low differential pressure

• Much lower ΔP than PTFE membranes
• Lower energy consumption
• Stability for sensitive filling/packaging air systems
• Delivers the same flow with fewer cartridges or smaller housings

Outcome:
✔ Lower CAPEX (smaller housings, smaller compressors)
✔ Lower OPEX (energy savings, less filter replacement)

High dirt-holding capacity

Glass fibre depth-pleated media handles large particulate and aerosol loads extremely well when protected by a coalescing filter.

Ideal applications

• Tank vents
• CO₂ and nitrogen sterile gas lines
• Filling machines
• Powder handling and conveying
• Sterile instrument air
• High-flow sterile gas systems

Option B: Hydrophobic Membrane (PTFE Membrane Filters or PVDF Membrane Filters)

• Industry-standard sterilising grade
• Validated retention (B. diminuta)
• Excellent chemical resistance
• Typically chosen when regulatory expectations are highest

When to use which?

• Glass fibre: when optimising ΔP, CAPEX, and OPEX
• PTFE membrane: when maximum sterility margin or regulatory conservatism is required
• Both are validated sterile gas solutions.

Steam Filtration for Dairy and Food Processing

Steam supports sterilisation, heating, cooking, and hygiene systems.

Steam Types & Filtration Requirements

Culinary steam must comply with 3-A 609-03 and EHEDG hygiene guidelines.

Regulatory Compliance for Gas & Steam Filters

All food and dairy gas/steam filtration systems must meet:

• EU Regulation 1935/2004
• FDA CFR Title 21 (materials of construction)
• ISO 8573-1 (compressed air purity)
• ISO 12500 series (coalescing filter validation)
• 3-A 609-03 (culinary steam)
• EHEDG hygienic design guidelines
• EN 1672-2 (hygiene of machinery)

Pleated glass fibre, PTFE membrane, polypropylene, and stainless steel media all comply when properly manufactured.

 Final Thoughts

A modern, hygienic sterile gas system requires only two stages:

✔ Coalescing Prefilter (removes aerosols and condensate)

✔ Sterile Gas Final Filter (glass fibre or PTFE membrane)

Pleated glass fibre sterile gas cartridges now offer validated sterility with much lower pressure drop, enabling smaller housings, fewer cartridges, and lower energy consumption — reducing both CAPEX and OPEX while maintaining full sterile assurance.

If you have any questions on filtration solutions for gas and steam applications, then you can give us a call or send us an email - we’d be more than happy to help. 

You can also read more:  

• Steam Applications
• Sterile Gas Applications
  
• Demystifying Culinary Steam Filtration
• Membrane vs. Depth Filtration in Microfiltration: A Technical Comparison

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