What you need to know about compressed air quality and its classification when planning a compressed air installation
The operator of the compressed air installation that you are specifying has particular requirements for compressed air quality. If the compressed air is contaminated and then comes into contact with the end product, this can disrupt production and lead to higher scrap rates. Just one example: one drop of oil could cause the foam of an entire beer bottle to collapse. As a result, a seemingly cheap solution for compressed air production can become very expensive.
It is, therefore, crucial that the quality of the compressed air output meets the requirements of the production line. When designing the compressed air system, future demand should also be taken into account as far as possible - if only in the form of sufficient space for expansion.
Water, oil and dust particles contaminate compressed air and may need to be removed
Compressed air can contain various impurities, the most relevant ones for industrial manufacturing being water, oil, and dust particles. Depending on the compressed air application, these impurities can increase running costs. As such, the purpose of compressed air treatment is to ensure the quality of compressed air required by the user. The best way to find out precisely what air quality is needed by the application is to ask the responsible facilities manager or maintenance engineer.
When planning the compressed air installation, you should always ensure to provide sufficient space for all of the processing equipment required by the application.
The typical compressed air system should include these ancillaries
Various treatment devices are available to remove unwanted elements such as particulate, oil, and water contained in compressed air. Some air compressors, such as plug and play compressors[LINK HERE], may even integrate the most common compressed air treatment ancillaries for ease of installation and a smaller footprint. The typical compressed air installation should always include the following ancillaries:
- aftercooler,
- oil-water separator,
- refrigerant air dryer or desiccant adsorption air dryer
- line filter(s)
This article [LINK HERE] goes into depth on the details of these components and their importance for the quality of compressed air.
Quality / purity classes of compressed air according to ISO 8573-1
Depending on the amount of the three contaminating components - particles, water and oil - compressed air is classified into quality classes or cleanliness classes (see table), which are defined by ISO 8573-1. More details on the definitions of the standard can be found below. In our chapter on compressed air preparation, we explain the three main undesirable components of compressed air and briefly outline how they can be removed.
ISO classes of compressed air quality
The primary, authoritative standard for compressed air quality is ISO 8573-1, a series of guidelines that help classify compressed air quality and thus make it comparable. We would like to introduce them to you briefly here.
The ISO 8573 series of standards provides concrete definitions:
- basic terminology of compressed air treatments,
- the three main impurities in compressed air (see above: particles, water or moisture, and oil,
- a standardized method for describing the required or measured compressed air purity,
- the reference values of the respective data,
- a classification method to specify the three main impurities in compressed air in purity classes,
- other relevant gaseous impurities (such as sulfur and nitrogen oxides) and microbiological contaminants,
- the corresponding standardized measuring methods for the particular contaminants.
What you need to know about compressed air quality and its classification when planning a compressed air installation
