Compressed air purity Standards

Achieving ISO 8573-1 Class 0 Oil-Free Air with Inline Filtration

Posted on by sales

In many critical applications, “clean” air isn’t just a preference; it’s a regulatory requirement. In industries like pharmaceuticals, food processing, and electronics consider ISO 8573-1 Class 0 the gold standard for purity.

At National Filters Pty Ltd, we often help clients dispel the misconception that achieving Class 0 requires expensive oil-free air compressors. While many assume that only oil-free compressors can meet the highest standards, inline filtration offers a more robust, cost-effective solution for obtaining “technically oil-free” air that complies with ISO 8573-1 Class 0 specifications.

Understanding ISO 8573-1 Class 0 Benchmark

ISO 8573-1:2010 is the international standard for compressed air purity. While Class 1 allows for up to 0.01mg/m³ of total oil, Class 0 is even more stringent. . It is a specific requirement set by the end user to achieve levels below Class 1, often requiring air that is 100% free of hydrocarbons, oil aerosols, or oil vapours. Even oil-free air compressors can pass oil into the system. They can suck in hydrocarbons from the atmosphere in the form of air pollution, which is then condensed in the compression phase and pumped out into the air lines.

How Inline Filtration Delivers Oil-Free Air

While ”technically oil-free” air is often associated with oil-free compressors (mainly by the companies selling them), the right combination of high efficiency filters can strip out contaminants to nearly undetectable levels while using standard lubricated air compressors.

The Multi-Stage Filtration Process

Achieving this level of purity requires a multi-stage approach to address different forms of contamination.

1. High-Efficiency Coalescing Filtration

The first line of defence is a coalescing filter. These filters, such as our 0.01 micron elements, are designed to remove bulk liquid and oil mist and aerosols. To protect these sensitive elements, we recommend a 1 micron pre-filter to capture larger particles and water droplets.

2. Oil Vapour Removal with Activated Carbon

Standard coalescing filters cannot remove oil vapour or odour, which can still contaminate sensitive processes. To achieve true Class 0 air, an activated carbon filter or carbon tower must be installed downstream. These use adsorption to reduce oil vapour levels to as low as 0.003mg/m3.

3. Strategic Point-of-Use Installation

For maximum efficiency, filtration should be installed as close to the point of use as possible. This prevents re-contamination from the piping system. In critical environments, using stainless steel piping is also recommended. This avoids particle generation that can occur with other piping materials.

Overcoming Temperature – Related Oil Carryover in Inline Systems

Filtration performance is highly dependent on the air temperature. As compressed air temperature increases, oil carryover also increases. To guarantee Class 0 air, your system must include effective compressed air dryers and/or aftercoolers to keep the air cool and dry before it hits the final stages of filtration.

Why Choose Inline Filtration Over Oil-Free Air Compressors?

  • Cost efficiency: Implementing a high grade inline filtration system often requires a lower initial capital investment than a dedicated oil-free air compressor.
  • Flexibility: You can upgrade your existing lubricated compressed air system to meet Class 0 standards at specific points of use rather than replacing the entire plant.
  • Reliability: With the correct filtration set up, you can gain peace of mind knowing that your air purity is consistent when it’s monitored and maintained.
  • Protection: Safeguard your products from spoilage and your equipment from costly downtime.
  • Expert Guidance: Our team offers expert advice to tailor a solution to your unique needs.

OIL-FREE COMPRESSOR

FILTRATION SOLUTION

High Initial Investment

Lower Investment (uses existing assets)

Costly Specialist Maintenance

Simple, Cost-Effective Maintenance

Fixed Solution Plant Wide

Flexible, Scalable, Point of Use

Redundancy Requires 2nd Unit   

Easily Parallelised and Replicated

Cost of ownership between a new oil-free compressor and an inline filtration upgrade

Why Choose National Filters?

As an Australian owned and operated wholesaler, National Filters Pty Ltd provides expert guidance and local support to protect your critical processes. We are specialists in compressed air treatment. We provide a comprehensive range of compressed air treatment products from Europe to ensure your system remains compliant with the highest industry standards.

Ready To Upgrade Your Air Quality?

Don’t leave your product quality to chance. Contact the experts at National Filters today to discuss your filtration requirements and ensure your facility meets Class 0 standards.

    Leave a Reply