The compressor, as designed, will supply air that is potentially not at the operating characteristics the manufacturer wishes to be at for the classification process. Here are some tips which may need to be considered before the assessment process starts:
A. Have your compressor prepared for testing. Engineering sampling ports may be required to sample UPSTREAM AND DOWNSTREAM flow patterns. Sampling ports can be described as fittings which allow for air sampling in the flow-stream. The downstream is considered finished product (air discharge), and the upstream is considered the control sample and is usually the inlet air. A compressor should be engineered with sampling ports to sample both sources of air. A clear understanding of this section is required to ensure accurate assessment.
B. Have your compressor cleaned for testing. Approved solvents are available that may be useful in cleaning any foreign matter, particulate, oil deposits, and or gasket lubricants from the air pathway to minimize potentially misleading results.
C. Remove and replace stored water supplies for Water Jacketed compressors if microbiological testing is to be performed. Stagnant water may harbor bacteria over extended periods of time.
The approach to classification should take into consideration the attributes desired, and subsequently the selection of the appropriate ISO 8573 standard, and appropriate Part. Once this has been determined, a methodical approach based on the recommendations (at a minimum) listed here should be considered.
In addition the sampling apparatus in some cases is diagramed for the actual testing in the ISO 8573 Parts 1 through 9. If the sampling apparatus is not available then in-house design and or outsourcing will be required.