Oil-free compressed air is used in all kinds of industries where air quality is important for the end product and the production process. These applications include food and beverage processing, pharmaceutical manufacturing and packaging, chemical and petrochemical processing, semiconductor and electronics manufacturing, the medical sector, automotive paint spraying, textile manufacturing and many more.
For the past 60 years, Atlas Copco has been pioneering the development of oil-free air technology, resulting in a range of oil-free air compressors designed specifically for applications that can make no compromise when it comes to clean, 100 percent oil-free air.
By maintaining and strengthening its world-leading position through continuous research and development, Atlas Copco was able to achieve a new milestone in setting the standard for air purity. It was the first manufacturer to be awarded ISO 8573-1, ed3. 2012, Class 0, for oil content.
Why Class O?
Industries such as pharmaceuticals, food and beverages, electronics and textiles need technology that excludes any risk of contamination, and the severe consequences that can follow. This can include spoiled or unsafe products, production downtime, or costly product recalls and legal issues, which can damage their brand and reputation.
They therefore look to ISO 8573-1 (2010) certification, which establishes a comprehensive classification and measurement methodology in which Class 0 represents the best possible air quality. This is what brings them back to Atlas Copco time after time, the ability to provide their customers with the very best.
Atlas Copco looked to the Technische ÜberwachungsVerein (Technical Monitoring Association), or the TÜV, to type-test its range of oil-free air compressors. The TÜV is an independent, international organization specializing in evaluating the safety and quality of products. The TÜV is recognized worldwide for its independence, neutrality, professional expertise and strict standards.
It is important to understand the main differences between the first ISO 8573-1, ed 1, 1991 and the later versions. The 1991 edition of the ISO 8573-1 standard established five classes of air purity, 1-5, with Class 1 being the purest. However on oil content, only oil aerosols and liquids were taken into consideration. Below 35°C (95°F), vapors could be ignored.
Later, higher levels of air purity were considered necessary for critical applications such as pharmaceuticals, food processing and the manufacture of critical electronic components.
In 2001, the standard was revised. A higher Class of air purity was added: ISO 8573-1 class 0. In addition, measurements now cover all three forms of oil contamination – aerosols, vapor and liquid – providing a true picture of air quality.
The 2010 edition of the standard confirmed the oil classification introduced in 2001. Atlas Copco has made a point of staying abreast of these developments, and the company has acquired the certification according to this latest standard.
After Atlas Copco asked the TÜV to type-test its range of oil-free air compressors, they were submitted to the most rigorous testing methodologies available. All possible oil forms were measured across a wide range of temperatures and pressures.
The TÜV found no traces of oil in the output air stream. Atlas Copco has thereby become the first compressor manufacturer to receive certification for the industry standard of air purity: ISO 8573-1 ed 3 Class 0 for oil content.
Even with the most comprehensive test method, no traces of oil were found
Both methods are acceptable for aerosol and liquid measurement according to ISO 8573 Part 2.
The B2 method samples only the center of the airflow. Oil aerosols are registered but oil that sticks to the pipe wall (wall flow) is not detected. Most air compressor manufacturers still prefer this less stringent method.
The B1 method examines the entire airflow to measure both aerosols and wall flow. This comprehensive test method was used on the Atlas Copco oil-free air compressors. Even so, no traces of oil were found in the output air stream.
There are a number of tests required to qualify for ISO 8573-1 Class 0. The Part 2 test measures aerosols and liquids. Testing can be done through partial flow (B2) or full flow (B1) methods. The Part 5 test measures vapors only.
Both parts are necessary to obtain ISO 8573 Class 0 certification. This means that all three forms of oil contamination – aerosol, vapor and liquid – have to be measured.
Only oil-free air compressors deliver 100 percent oil-free air. Atlas Copco developed its oil-free air compressors for applications demanding the highest levels of purity. Whether a customer’s activities are in pharmaceutical production, food processing, critical electronics or in a similarly exacting industry, zero oil means zero risk. This includes zero risk of contamination and zero risk of damaged or unsafe products, or of losses due to operational downtime. Above all, zero oil means zero risk of ruining a company’s hard-earned reputation.
Atlas Copco’s compressors offer reliability and efficiency, reducing downtime and maintenance and increasing yield. So even industries that are not as heavily reliant on 100 percent clean air appreciate and seek out the value that this technology can add to their business.
Can oil-injected compressors (which are sometimes called lubricated, coolant cooled or contact cooled compressors) with oil removal filters deliver oil-free air?
This solution is often referred to as “technically oil-free air.” However, even under optimum conditions and with several stages of oil removal, the air quality with regard to oil is suspect.
With oil-injected compressors there will always be a risk of contamination and the possibility of consequences for the business. With Atlas Copco’s oil-free air compressors, customers are choosing for zero risks, as oil-free air is guaranteed to be oil free.
It is also important to note that oils designated as “Food Grade Oils” are considered by some users as edible oils and hence completely safe. In reality, contamination with these oils can have a serious health impact on consumers.
Then there is the concern of oil contamination in ambient air. Ambient air has very small traces of oil coming from vehicles and industrial sources. However, in contaminated areas, oil content does not normally exceed 0.003 mg/m3.
This is borne out by tests conducted by the TÜV near a factory with heavy machining activity (including turning, milling, grinding and drilling). Heavy vehicular traffic and a garbage incinerator were in the vicinity.
Aspirated by an oil-free air compressor, this extremely low level of atmospheric oil is washed away by the condensate in the intercooler and aftercooler. The result is in pure oil-free air for the processes of prospective customers.
In the end, Atlas Copco has come to learn that its customers prefer to be environmentally friendly. With Atlas Copco’s oil-free air technology, leaks and energy waste are minimized. Additionally, the need for condensate treatment is eliminated.
The amount of lubricating oil required is a fraction of the quantity in oil-injected compressors. This means customers can safeguard the environment and better comply with international regulations.