Unlike other utilites, which are supplied to site by a supplier to strict tolerances and quality specifications, compressed air is generated on-site. The quality of the compressed air and the cost of producing this powerful utility is therefore the responsibility of the user.
The use of compressed air is often critical to manufacturing processes. A clean, dry, reliable compressed air supply is essential to maintain efficient and cost effective production.
Untreated compressed air contains many potentially harmful or dangerous contaminants, which must be removed or reduced to acceptable levels.
What Influences Your Compressed Air Quality?
Dirt, moisture and oil are everywhere. But they shouldn’t be in your compressed air supply.
Dust, dirt, pollen, microorganisms, smoke, exhaust emissions and other particulates
Moisture in the form of water vapour
Oil, unburned hydrocarbons from the ambient air and compressor coolant carryover
Caustic gases such as sulfur oxides, nitrogen oxides and chlorine compounds.
Compressed Air Quality ISO 8573-1:2001
|Air Quality Class||Solids||Water||Oil & Oil Vapour|
|Max Number of Particles Per m3||Pressure Dew Point|
|0.1 – 0.5 micron||0.5 – 1 micron||1– 5 micron||°C||mg/m3|
|0||As specified by the end-user or manufacturer, and more stringent than Class 1|
The Results of Contaminated Compressed Air
The problems created by contaminated compressed air in your system can range from annoyance to wreaking havoc on your equipment and your end products.
• Premature wearing and scoring of surfaces
• Rust and corrosion in tools, piping and equipment
• Damaged instruments
• Spoiled paint surfaces
• Increased scrap rate
• Unsafe or unpleasant work environment
Removing Particulate (Air Filtration)
Think of it as a mini dust storm at pressure. Solid particles can enter the compressed air system via atmospheric dirt or even from the effects of corrosion and wear within the compressed air system.
• Systems are damaged and products are spoiled
• Scoring and uneven wear patterns ruin tools and instruments
• Volatile, hazardous compounds are produced
• Production shuts down, productivity and quality suffer
Placing different grades of filtration in the compressed air system, before and after dryers, or even at point of use will eliminate these particles depending on the class of air required.
Water is present in atmospheric air, depending on the relative humidity and ambient air conditions.
Moisture Contamination Has The Following Effects:
• Rust and corrosion in the air system piping
• Inadequate air tool lubrication
• Damage to labelling, packaging and the finished goods
• Productivity losses throughout your operation
Treating the air through the appropriate dryer technology, will reduce the water content within the air to the required pressure dew point.
Oil in Compressed Air Affects Products and the Work Environment
Oil, unburned hydrocarbons and compressor coolant become highly concentrated during compression.
• These contaminants enter the air flow as entrained droplets and will pass through the compressed air system into the production process unless they are removed.
• The built-in air/oil separator on all rotary screw air compressors will remove a portion of the oil, but this is not sufficient for most applications.
• Oil contamination will cause batch spoilage, poor quality in finished goods, unwanted colouring in finished goods and a messy or hazardous work environment.
Proper Filtration Removes Unwanted Oil from the Air Stream
Removing oil from the compressed air stream provides some real benefits.
• Longer air tool life
• Ensures high quality of finished goods
• No unwanted odours
• Safer workplace
Liquid Oil will be collected through the appropriate coalescing filtration and drying of the compressed air. However removal of Oil Vapour will require additional activated carbon filters.
Waste by-products produced by the treatment of the air must be managed and disposed of appropriately and in accordance with local laws and regulations.