Is your manufacturing plant's compressed air purity validated? Perhaps the methods you are employing to check the purity or quality of the air in your facility are only indicative? Is there a difference?
The answer to this last question is yes. There is a difference, and it matters in how companies present their capabilities and quality.
Here, we will discuss the standard that defines the sampling methodology and equipment that must be employed in order to present compressed air purity (quality) as validated. We will also learn the relevance of practices that are indicative of the compressed air quality and differentiate them from those that present complete validation.
Download this white paper for an in-depth look at what is required to test compressed air for ISO validation purposes, methods and equipment used for indicative testing, as well as cost-effective performance validated compressed air treatment options.
Validation - ISO compressed air purity standards
The ISO 8573 Series has been the international standard for compressed air purity (quality) since 1991. It is used to define the quality of compressed air used for a variety of applications across manufacturing industries worldwide. The standard is segmented into nine distinct parts.
Beginning with ISO 8573-1, users are provided a method of classification with specific contamination types and limits defined. This method is employed by compressed air users to select the treatment equipment that they will need in order to produce certain air quality. In kind, ISO 8573-1 is used by compressed air treatment equipment manufacturers to define the quality of compressed air delivered by their products and systems.
But in order to claim compressed air purity is actually validated, users and manufacturers must go beyond IS0 8573-1 to the remaining eight standards, as shown in the above illustration. ISO 8573 parts 2 through 9 have been developed to provide the most accurate measurement of the main contaminants found in a compressed air system. In the standards, the user is presented with the equipment and methodology that must be employed to accurately test and claim validation. It offers specifics for the accurate measurement of common compressed air contamination — solid particles, water vapor and total oil — as well as contamination of specific interest to certain industries, like microbial contamination in food, beverage and pharmaceutical manufacturing applications.
Indicative testing is basically purity and quality testing that is performed in a manner that is not carried out in accordance with ISO 8573 parts 2 thru 9. If the ISO standard is not followed, a company cannot claim validation on the levels of certain contaminants in their compressed air supply.
While indicative testing can not be used for validation purposes, it still can provide valuable information to compressed air users. It may satisfy that some air quality testing is conducted, required in certain industries. It remains, however, important for the users to understand the limits of the testing equipment and methodologies it employs. The chart below offers an overview of commonly available test equipment used for indicative testing of compressed air systems.
Examples of indicative testing
- Not using iso-kinetic sampling methods when required.
- Use of flow regulators / pressure regulators which change the pressure / air velocity / temperature / contaminant concentration of a sample.
- Total oil testing using PID based digital oil analyser.
- Total oil testing using chemical detector tubes.
- Particulate testing using particle counters that do not count in required particle bands.
- Particle testing using particle analysers that do not measure down to lowest particle size required by the ISO 8573-1 standard.
- Measuring water vapour with chemical detector tubes.
Performance validated compressed air treatment equipment
The cost and complexity of testing and validating compressed air purity in accordance with ISO standards can be prohibitive. Therefore, products that are third party validated are an attractive option.
Parker Hannifin Corporation, a leader in compressed air treatment, offers a complete range of products with 3rd party validated performance. These state-of-the-art components and systems are backed by an air quality guarantee.
The Parker OIL-X range of compressed air filters and Parker adsorption dryer ranges have been designed to provide compressed air purity (quality) that meets or exceeds every classification shown in all editions of ISO 8573-1. Filtration and dryer performance has also been independently 3rd party verified by Lloyds Register.
For an in-depth look at what is required to test compressed air for ISO validation purposes, methods and equipment used for indicative testing, as well as cost-effective performance validated compressed air treatment options., download this white paper.
This article was contributed by Mark White, compressed air treatment applications manager, Parker Gas Separation and Filtration Division EMEA