ISO 8573 Compressed Air Quality

ISO 8573 is the group of international standards relating to the quality of compresed air. These documents are broken down into nine parts, part one specifies the quality requirements of the compressed air and parts two to nine specify the methods of testing for a range of contaminates.

ISO 8573.1

Purity levels for the main contaminates are shown in seperate tables, however below we have cobined all three to make it easier to follow.

			Solid Particles			Water		Oil
Purity Class		Max No. of particles per m3		Particle Size	Concentration			Total Oil
	0.1-0.5 micron	0.5-1 micron	1-5 micron	micron	mg/m3	Pressure Dewpoint	g/m3	mg/m3

0	NA*	NA*	NA*	NA*	NA*	NA*	NA*	NA*
1	100	1	0	-	-	-70c	-	0.01
2	100,000	1000	10	-	-	-40c	-	0.1
3	-	10,000	500	-	-	-20c	-	1
4	-	-	1000	-	-	+3c	-	5
5	-	-	20,000	-	-	+7c	-	-
6	-	-	-	5	5	+10c	-	-
7	-	-	-	40	10	-	0.5	-
8	-	-	-	-	-	-	5	-
9	-	-	-	-	-	-	10	-

* As specified by the equipent user or supplier

When writing a a purity specification it should be in the form ISO 8573.1 : 2001 Class S.W.O
For example ISO 8573.1 : 2001 Class 1.2.1 - would mean class one for solid particles, class two for water, class one for oil.

Equipment required to meet the grades

The following table shows what equipment is required to meet each grade specified above

	Solid Particles	Solid Particles	Water	Oil
Purity Class	Wet Particulate	Dry Particulate	Vapour	Total Oil

1	Pre-filter, Micronic filter, & High efficiency filter	AR Pre filter, AAR Micronic filter, High efficiency filter	Adsorption dryer	Pre-filter, Micronic filter & Activated carbon filter
2	Pre-filter, Micronic filter	AR Pre filter, AAR Micronic	Adsorption dryer	Pre-filter, Micronic filter
3	Pre-filter	AR Pre filter	Adsorption dryer	Pre-filter
4	Pre-filter	AR Pre filter	Refrigeration dryer	Pre-filter
5	Pre-filter	AR Pre filter	Refrigeration dryer	-
6	-	-	Refrigeration dryer	-

General purpose oil free air is considered ISO 8573.1 Class 2.4.2
In a typical environment this is achieved by installing a pre-filter, refrigeration dryer, micronic filter.

For further advice and information on current standards for compressed air systems please contact us here