Oil-Free Compressors
for Clean Air Applications
When any oil in your compressed air is a product quality risk, a compliance failure, or a safety hazard, oil-free compression is the only answer. No oil in the compression chamber means zero risk of oil contamination in your air supply.
When Oil-Free Matters
Industries where compressed air contacts the product, the process, or the environment. Oil contamination in these applications means product rejection, compliance failure, or safety risk.
Food and Beverage
Direct contact with product packaging, bottle blowing, ingredient conveying, and nitrogen generation. Oil contamination is a product recall risk. Class 0 air removes that risk entirely.
Pharmaceutical
Tablet pressing, coating, packaging, and clean room pressurisation. GMP compliance requires documented proof of air purity. Oil-free compressors simplify that audit trail.
Electronics
Semiconductor fabrication, circuit board assembly, and component cleaning. Even trace oil vapour can cause defects in precision manufacturing processes.
Breathing Air
Diving, fire services, hospital medical air, and confined space entry. BS EN 12021 breathing air quality standards require oil-free compression at source.
Spray Finishing
Automotive paint shops, furniture finishing, and aerospace coating. Oil in the air supply causes fish-eye defects, adhesion failure, and costly rework.
Textile Manufacturing
Air-jet weaving, yarn texturing, and fabric treatment. Oil contamination stains product and contaminates dye processes. Oil-free air protects product quality at source.
ISO 8573-1 Air Quality
The international standard for compressed air purity classifies contaminants across three categories: solid particles, water, and total oil (aerosol, liquid, and vapour). Understanding these classes is essential for specifying the right compressor and downstream treatment.
| Class | Total Oil (mg/m3) | Typical Application |
|---|---|---|
| Class 0 | As specified by user | Pharmaceutical, breathing air, semiconductor |
| Class 1 | 0.01 | Food contact, electronics, spray finishing |
| Class 2 | 0.1 | General manufacturing, packaging |
| Class 3 | 1.0 | Workshop tools, general pneumatics |
| Class 4 | 5.0 | Non-critical applications |
Oil-Free Range
Our current oil-free offering. All models supplied, installed, and maintained by Airmech with PSSR compliance included.
CompAir D-Series
ISO 8573-1 Class 0 certified oil-free rotary screw compressors. Water-injected compression with no oil in the compression chamber. Suitable for food, pharmaceutical, and electronics manufacturing.
View range and specificationsBuy and Maintain
with One Partner
We supply it, we install it, we service it. Oil-free compressors require specialist knowledge for service and commissioning. As an authorised CompAir distributor, our engineers are factory-trained on the D-Series platform. One contract covers purchase, installation, planned maintenance, and PSSR compliance.
Frequently Asked Questions
What is the difference between oil-free and oil-lubricated compressors?
Oil-lubricated compressors use oil in the compression chamber for sealing, cooling, and lubrication. Some oil carries over into the compressed air output, typically 2 to 5 mg/m3 before filtration. Oil-free compressors use no oil in the compression chamber, so there is zero risk of oil entering the air stream. This is a fundamental design difference, not simply a matter of filtration.
Can filtration make an oil-lubricated compressor oil-free?
No. Coalescing filters and activated carbon towers can reduce oil content to very low levels (0.01 mg/m3 with multi-stage filtration), but they cannot guarantee zero oil. Filter performance degrades between changes, and breakthrough can occur without warning. For applications where any oil contamination is unacceptable, an oil-free compressor is the only reliable solution.
What does ISO 8573-1 Class 0 mean?
ISO 8573-1 is the international standard for compressed air quality. It classifies air purity across three contaminants: particles, water, and oil. Class 1 permits up to 0.01 mg/m3 of total oil. Class 0 is the most stringent classification, defined as 'more stringent than Class 1' with limits specified by the equipment user or application standard. CompAir D-Series compressors are Class 0 certified by TUV.
Are oil-free compressors more expensive to run?
Oil-free compressors typically have a higher purchase price than oil-lubricated equivalents. However, they eliminate the cost of oil removal filtration, condensate treatment (oil/water separators), and the ongoing replacement of coalescing filter elements. When the full system cost is considered, including downstream equipment and compliance documentation, the total cost of ownership is often comparable.
Do you supply and service oil-free compressors?
Yes. Airmech is an authorised CompAir distributor supplying the D-Series oil-free range from 15 to 37 kW. We install, commission, and maintain oil-free compressors under the same service contracts as our oil-lubricated range. PSSR compliance is included as standard.
Need Oil-Free Air?
Tell us your application, air quality requirement, and demand profile. We will recommend the right oil-free compressor, downstream treatment, and monitoring solution.