Compressed air quality is measured by the amount of solid particulates, water and oil content in one cubic foot (cu. ft.) of compressed air. Many of these contaminants are introduced from the air surrounding the installation site that is drawn into the system at the beginning of the compression process. The relative humidity, type of compressor and air treatment and filtration system can also affect air quality. Minimum air quality requirements vary by industrial application; the most stringent standards apply to manufacturers whose end products, packaging or critical instrumentation come in direct contact with compressed air.
ISO and CAGI
Many astute air compressor users have noticed the Compressed Air and Gas Institute (CAGI) air compressor data sheets, dated after June 2020, have a new term listed; isentropic efficiency. Isentropic Efficiency will be the new standard of reference for a true comparison of the overall efficiency of air compressors at any rated discharge pressure. Now users can see which company produces the most efficient product with an easy reference percentage number. The compressed air industry, in conjunction with CAGI, has been trying to make fair comparisons between air compressors for years.
The next time you sit down for dinner, take a good look at your food. There’s a very good chance compressed air played an essential role in preparing your meal for consumption.
If you have ever looked at the small print of a compressor brochure or a CAGI Data Sheet or a compressor technical information page, you have probably seen some reference to one of the above standards. At one time or another, US compressor manufacturers have used these standards to test and report compressor performance. These are referred to as “Acceptance Test” codes.
Most readers of this magazine are familiar with the ISO 9000 and 14000 families of standards. The 9000 family pertains to quality management systems and the 14000 family deals with environmental management.
Industry standards serve a very important purpose for the end users of compressed air equipment. If the standards are well written, they can help to promote the equipment that they govern, as long as the equipment manufacturers properly apply and promote the standards.
Compressors in today’s market must meet a variety of standards written by a wide range of organizations throughout the world. Until recently, most standards were written to deal with safety, both mechanical and electrical, and performance of the individual components of a compressed air system.