BS ISO 8573-1-2001 Compressed Air - Part 1 Contaminants and Purity Classes

   I    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

BRITISH STANDARD

Compressed air — Part 1: Contaminants and purity classes

ICS 71.100.20

NO COPYING WI THOUT BSI PERMISSION EXCE PT AS PERMIT TE D BY COPYRI COPYRI GHT LAW

BS ISO 8573-1:2001

   I BS ISO 8573-1:2001    S    B    )   c    (  ,   y   p   o    C This British Standard reproduces verbatim ISO 8573-1:2001 and implements    d   e it as the UK national standard.    l    l   o   r The UK participation in its preparation was entrusted to Technical Committee    t   n MCE/8, Compressors, pneumatic tools, pneumatic machines and vacuum   o technology, which has the responsibility to:   c   n    U  ,    6  — aid enquirers to understand the text;    0    0    2  — present to the responsible international/European committee any    0 enquiries on the interpretation, or proposals f or change, and keep the    0   : UK interests informed;    0    0  — monitor related international and European developments a nd   +    T promulgate them in the UK.    M    G  A list of organizations represented on this committee can be obtained on    1    5 request to its secretary.   :    2    2 Cross-references   :    7    1 The British Standards which implement international publications referred to    2 in this document may be found in the BSI Standards Catalogue under the    2 section entitled “International Standards Correspondence Index”, or by using   c   e the “Find” facility of the BSI Standards Electronic Catalogue.    D    i  A British Standard does not purport to include all th e necessary provisions of   r    F a contract. Users of British Standards are responsible for their correct  , application.   y    t    i   s   r Compliance with a British Standard does not of itself confer immunity   e from legal obligations.   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L This British Standard, having  ,   y been prepared under the Summary of pages    t    i direction of the Engineering   s This document comprises a front cover, an inside front cover, the ISO title page,   r Sector Committee, was   e published under the authority pages ii to iv, pages 1 to 8, an inside back cover and a back cover.   v of the Standards Committee    i   n and comes into effect on The BSI copyright date displayed in this document indicates when the    U 15 May 2001 document was last issued.    k   n   a    B    h  Amendments issued since publication    t   u   o    S  Amd. No. Date Comments   n   o    d   n © BSI 05-2001   o    L   :   y   p   o    C    d   e   s   n ISBN 0 580 37489 0   e   c    i    L

National foreword

   I    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

INTERNATIONAL STANDARD

ISO 8573-1 Second edition 2001-02-01

Compressed air — Part 1: Contaminants and purity classes Air comprimé —  Partie 1: Polluants et classes de pureté 

Reference number ISO 8573-1:2001(E)

   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

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ISO 8573-1:2001(E)

Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 8573 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 8573-1 was prepared by Technical Committee ISO/TC 118,   Compressors, pneumatic  tools and pneumatic machines , Subcommittee SC 4, Quality of compressed air . This second edition cancels and replaces the first edition (ISO 8573-1:1991), which has been technically revised. ISO 8573 consists of the following parts, under the general title Compressed air :  — Part 1: Contaminants and purity classes   — Part 2: Test methods for aerosol oil content   — Part 3: Test methods for measurement of humidity   — Part 4: Test methods for solid particle content   — Part 5: Determination of oil vapour and organic solvent content   — Part 6: Determination of content of gaseous contaminants  The following parts are in preparation:  — Part 7: Test methods for viable microbiological contaminant content   — Part 8: Contaminants and purity classes (by mass concentration of solid particles)  — Part 9: Test methods for liquid water content 

iii

   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n Introduction   o   c   n This part of ISO 8573 is one in a series of standards (planned or published), with the ambition of harmonizing air con   U  , tamination measurements.    6    0    0 The source of odours from a compressed air supply may be present due to a number of factors. The presence of an    2    0 odour results in discomfort to personnel using breathing equipment. The means of detection is the human olfactory    0   : system and the person involved bases the quantification on a subjective analysis. No reliable measurement methods    0 are available therefore each situation must be treated as an individual case and appropriate action taken to minimise    0   + the discomfort. For the time being there will be no separate part of ISO 8573 dealing with odours.    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

iv

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INTERNATIONAL STANDARD

ISO 8573-1:2001(E)

Compressed air — Part 1: Contaminants and purity classes

1 Scope This part of ISO 8573 specifies purity classes of compressed air in respect of particles, water and oil regardless of the source of the compressed air. This part of ISO 8573 identifies microbiological and gaseous contaminants. The gaseous contaminants included in this part of ISO 8573 are carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen dioxide, nitric oxide and hydrocarbons with carbon atoms in the range C1  to C5. NOTE Other contaminants are taken into consideration for specific applications, e.g. air used for breathing, medical, food and beverage purposes.

2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this part of ISO 8573. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 8573 are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 7183, Compressed air dryers — Specifications and testing . ISO 8573-2, Compressed air for general use — Part 2: Test methods for aerosol oil content . ISO 8573-3, Compressed air — Part 3: Test methods for measurement of humidity . ISO 8573-4, Compressed air — Part 4: Test methods for solid particle content . ISO 8573-5, Compressed air — Part 5: Determination of oil vapour and organic solvent content.

3 Terms and definitions For the purposes of this part of ISO 8573, the terms and definitions given in ISO 7183 and the following apply. 3.1 aerosol suspension in a gaseous medium of solid particles, liquid particles or solid and liquid particles having negligible fallvelocity/settling-velocity 3.2 agglomerate group of two or more particles combined, joined or formed into a cluster by any means

1

   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p 3.3   o    C dewpoint    d temperature at which water vapour begins to condense   e    l    l   o   r 3.4    t   n microbiological organisms   o   c viable colony forming units which may be a bacteria, fungi or yeasts   n    U  ,    6 3.5    0    0 oil    2 mixture of hydrocarbons composed of 6 or more carbon atoms (C ) 6    0    0   :    0 3.6    0   + particle    T a small discrete mass of solid or liquid matter    M    G    1 3.7    5   :    2 particle size    2   : d    7 length of the greatest distance between two external boundaries.    1    2    2 3.8   c   e relative water vapour pressure    D relative humidity    i   r    F ratio of the partial pressure of water vapour to its saturation pressure at the same temperature  ,   y    t    i 3.9   s   r   e vapour   v    i   n gas which is at a temperature below its critical temperature and which therefore can be liquefied by isothermal com   U pression    k   n   a    B 4 Measurement of contaminants    h    t   u   o For the purpose of assessing the purity class of a compressed air sample, measurements shall be made in accord   S ance with the appropriate part of ISO 8573:   n   o    d  — Part 2 for measuring oil aerosols and oil liquid content of compressed air;   n   o    L  — Part 3 for measuring humidity;  ,   y    t    i  — Part 4 for measuring solid particles;   s   r   e  — Part 5 for measuring oil vapour and organic solvent content;   v    i   n    U Further parts of ISO 8573 are under preparation for measuring gaseous contaminant content (Part 6), for determin   k ing viable microbiological contaminant content (Part 7) and for measuring solid particles (Part 8) and liquid water   n   a content (Part 9). In their absence, other recognized standards shall be used for the measurement of the various con   B taminants, if possible, and the following rules apply:    h    t   u  — measurements shall be based on a number of samples taken during a suitable length of time;   o    S  — measurements should be carried out at the actual operating pressure and temperature;   n   o    d  — the purity classes of a compressed air system should be based on the mean value of an agreed number of meas  n urements (see note);   o    L   :  — the purity classes are relevant only at the point of measurement (see note).   y   p   o    C The content of particles, water and oil in compressed air varies due to sudden changes in the intake air, to the wear    d of components as well as to changes in flow, pressure, temperature and ambient conditions.   e   s   n   e   c    i    L

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ISO 8573-1:2001(E)

It is not possible to measure the full flow area of a compressed air stream using most test methods and therefore it is necessary to take samples of the air. Care should be exercised to ensure that the sample taken is representative of the compressed air purity. NOTE Measurements should be carried out at the actual operating conditions as otherwise the balance between impurities in liquid, aerosol or gaseous form will be altered. Liquid oil and free water in particular tend to cling to pipe and tube walls where they form a film or thin rivulets.

5 Standard atmosphere Reference conditions for volume statements shall be as specified in Table 1. Table 1 — Reference conditions ◦

Air temperature

20 C

Air pressure

1 bar a absolute

Relative water vapour pressure

0

a

1 bar =  0,1 MPa

6 Contaminants 6.1 General The three major impurities in compressed air are solid particles, water and oil. They influence each other (e.g. solid particulate agglomerates in the presence of oil or water to form larger particles, oil and water form an emulsion) and are sometimes deposited or condensed (e.g. oil vapour or water vapour) inside the pipework of a compressed air system. Other contaminants are also considered, including microbiological organisms and gaseous contaminants.

6.2 Solid particles 6.2.1 General Solid particle properties are important and are characterized by density, shape, size and by hardness. It is essential to eliminate the influence of water on particle size and number in order to obtain a correct reading. 6.2.2 Measuring parameters 6.2.2.1 Particle size Particle size shall be measured in accordance with recognized methods. 6.2.2.2 Particle concentration Concentration of particles shall be measured in accordance with ISO 8573-4. Mass concentration of particles shall be measured in accordance with a recognized standard (see clause 4). 6.2.2.3 Humidity The actual humidity level shall be measured in accordance with ISO 8573-3.

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   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p 6.3 Water   o    C    d   e    l    l 6.3.1 General   o   r    t   n Atmospheric air always contains water vapour. When atmospheric air is compressed the partial pressure of the water   o vapour increases but, owing to the increase in temperature caused by the compression, no water precipitates. When   c   n the air is subsequently cooled (e.g. in an intercooler or aftercooler, in the distribution pipework or during the expan   U  , sion process in a pneumatic tool) water will condense to liquid, but the air will be fully saturated with water vapour.    6    0    0    2 6.3.2 Measuring parameters    0    0   :    0 Humidity measurement shall be in accordance with ISO 8573-3 and for liquid water in accordance with a recognized    0   + standard (see clause 4).    T    M    G 6.4 Oil    1    5   :    2    2   : 6.4.1 General    7    1    2 For the purposes of this part of ISO 8573, oil in compressed air can belong to one or more of three categories: liquid,    2   c aerosol or vapour.   e    D When considering oil vapour content of compressed air it is important to reference the temperature as this affects the    i   r    F ratio of vapour to total oil content.  ,   y    t    i Testing for vapour should be carried out in conjunction with the test for aerosols and bulk liquid so the various phase   s   r   e concentrations may be discerned. Due to the complex organic molecules, which may be involved, the calibration pro  v cedure of the measurement equipment shall be clearly stated.    i   n    U    k   n 6.4.2 Measuring parameters   a    B    h    t   u 6.4.2.1 Oil liquid, aerosol or vapour   o    S   n The measurement of oil aerosol and liquid shall be in accordance with ISO 8573-2. The measurement of oil vapour   o    d shall be in accordance with ISO 8573-5.   n   o    L  , 6.4.2.2 Humidity   y    t    i   s   r The actual humidity level shall be measured in accordance with ISO 8573-3.   e   v    i   n    U 6.5 Gaseous contaminants    k   n   a    B Atmospheric air contains not only those common contaminants generally identified for treatment but also gaseous    h    t contaminants which may be present in varying amounts depending on location. Concentration of gaseous contami  u nants shall be measured in accordance with a recognized standard (see clause 4).   o    S   n   o 6.6 Microbiological organisms    d   n   o    L Microbiological organisms are generally considered to be solid contaminants, which can be present in the atmos  : pheric air. These organisms may be introduced into the compressed air by a number of means. If the microbiological   y   p organism is to be identified as a solid particle then the measurement method identified in ISO 8573-4 is used. If the   o    C colony forming activity of bacteria, fungi or yeasts is important then this can be identified using a recognized standard    d (see clause 4).   e   s   n   e   c    i    L

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ISO 8573-1:2001(E)

7 Compressed air purity classes 7.1 Solid particle classes The solid particle classes are defined in Table 2. Values for classes 0 to 5 shall be measured in accordance with ISO 8573-4 and for classes 6 and 7 in accordance with a recognized standard (see clause 4). Table 2 — Solid particle classes Maximum number of particles per m3 (see clause 5)

 

Particle size, d

Class

Particle   size

µm

 0,10

 

0,10 < d  0,5 0,5 < d  1,0

Concentration mg/m3

µm

1,0 < d  5,0

0

As specified by the equipment user or supplier and more stringent than Not class 1 applicable

Not applicable

1

Not specified

100

1

0

2

Not specified

100 000

1 000

10

3

Not specified

Not specified

10 000

500

4

Not specified

Not specified

Not specified

1 000

5

Not specified

Not specified

Not specified

20 000

6

Not applicable

5

5

7

Not applicable

 40

 10

NOTE A filtration ratio ( ) related to a particle size class is the ratio between the number of particles upstream of the filter and the number of particles downstream. This can be expressed as ( =  1 /P ) , where P  is the penetration of the particles expressed as the ratio of down stream particle concentration to upstream particle concentration. The particle size class is used as an index, e.g. 10 = 75 means that the number of particles of size 10 µm ( m) and larger is 75 times higher upstream of the filter than downstream.

7.2 Humidity and liquid water classes The humidity classes are defined in Table 3 and liquid water classes in Table 4. Values for pressure dewpoints shall be determined according to ISO 8573-3 and liquid water content according to a recognized standard (see clause 4). When lower dewpoints are required they shall be clearly specified. Table 3 — Humidity classes Class

Pressure dewpoint ◦

C

0

As specified by the equipment user or supplier and more stringent than class 1

1



3

−70  −40  −20

4

 +3

5

 +7

6

 +10

2

5

   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p Table 4 — Liquid water classes   o    C Concentration of liquid water, C w    d Class   e    l g/m3    l   o   r 7 C w  0,5    t   n   o 8 0,5 < C w  5   c   n 5 < C w  10    U 9  ,    6    0    0 7.3 Oil classes    2    0    0   : The oil classes are defined in Table 5. Values for oil aerosol and oil liquid shall be determined according to    0    0 ISO 8573-2 and oil vapour according to ISO 8573-5. The concentration of total oil is the sum of these values.   +    T Table 5 — Oil classes    M    G Concentration total oil (aerosol, liquid, and vapour)    1 Class mg/m3    5   :    2 As specified by the equipment user or supplier and more stringent than class 1    2   : 0    7  0,01    1 1    2 2  0,1    2   c 3 1   e    D 5 4    i   r    F  ,   y    t    i 7.4 Gases   s   r   e   v    i   n The reporting of the levels of gaseous contaminant content included within the scope of this part of ISO 8573 shall    U be determined as the actual determined values in accordance with a recognized standard (see clause 4).    k   n   a    B 7.5 Microbiological organisms    h    t   u   o    S Due to the complex nature of the involvement of microbiological organisms in many types of application the classifi  n cation in this part of ISO 8573 is limited to a simple identity based on sterile or non-sterile applications. Reporting of   o    d the levels of contaminant content included within the scope of this part of ISO 8573 shall be determined as the actual   n determined values in accordance with a recognized standard (see clause 4).   o    L  ,   y    t    i 7.6 Designation   s   r   e   v    i   n The designation of the purity class of compressed air at the specified measuring point shall include the following in   U formation in the order given:    k   n   a Compressed air purity classes ISO 8573-1 A B C    B    h    t   u where   o    S   n A is the figure for solid particle classes as measured in accordance with ISO 8573-4 (see 7.1);   o    d   n is the figure for humidity or liquid water classes as measured in accordance with ISO 8573-3 (see 7.2);   o B    L   :   y   p C is the figure for total oil classes as measured in accordance with ISO 8573-2 and ISO 8573-5 (see 7.3).   o    C    d When a class for any particular contaminant A, B or C is not specified, the designation shall be replaced by a hyphen.   e   s   n   e   c    i    L

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   I    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

ISO 8573-1:2001(E)

Additional qualification may be given on:  — gaseous contaminant content (see 7.4);  — microbiological contaminant content (see 7.5).

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   I ISO 8573-1:2001(E)    S    B    )   c    (  ,   y   p Bibliography   o    C    d [1] ISO 3649, Cleaning equipment for air or other gases — Vocabulary .   e    l    l   o   r    t [2] ISO 8573-6, Compressed air — Part 6: Determination of content of gaseous contaminants .   n   o   c   n [3] ISO 8573-7, Compressed air — Part 7: Test methods for viable microbiological contaminant content .    U  ,    6 [4] ISO 8573-8, Compressed air — Part 8: Contaminants and purity classes (by mass concentration of solid par ti-     0 cles).    0    2    0 [5] ISO 8573-9, Compressed air — Part 9: Test methods for liquid water content .    0   :    0    0 [6] PN 14M3, Contaminants, purity classes and measurement methods 1).   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C 1) PNEUROP Publications available from: PNEUROP General Secretariat, 33/34 Devonshire Street, London W1N 1RF.    d   e   s   n   e   c    i    L

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   I    S    B    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L   :   y   p   o    C    d   e   s   n   e   c    i    L

   I BS ISO    S    B 8573-1:2001    )   c    (  ,   y   p   o    C    d   e    l    l   o   r    t   n   o   c   n    U  ,    6    0    0    2    0    0   :    0    0   +    T    M    G    1    5   :    2    2   :    7    1    2    2   c   e    D    i   r    F  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L  ,   y    t    i   s   r   e   v    i   n    U    k   n   a    B    h    t   u   o    S   n   o    d   n   o    L BSI   :   y 389 Chiswick High Road   p   o    C London    d W4 4AL   e   s   n   e   c    i    L

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