SIST EN ISO 29461-1:2021

Air intake filter systems for rotary machinery - Test methods - Part 1: Static filter elements (ISO 29461-1:2021)

This document specifies methods and procedures for determining the static performance of particulate air filters used in air intake filter systems for rotary machinery such as stationary gas turbines, compressors and other stationary internal combustion engines. It applies to air filters with an efficiency of 85 % or more for the MPPS (EPA and HEPA filters) which are tested according to ISO 29463 (all parts) and filters with a lower efficiency which are tested according to ISO 16890 (all parts). The procedures described in both ISO 16890 (all parts) and ISO 29463 (all parts) are applied and extended by this document to air filters which operate at flow rates within the range 0,24 m3/s (850 m3/h) up to 2,36 m3/s (8 500 m3/h).
Static filter systems normally use multiple stages of coarse, fine and optional EPA or HEPA filter elements to protect the machinery. The scope of this document includes methods for performance testing of individual filter elements. It does not include methods for the direct measurement of the performance of entire systems as installed in service except in cases where they can meet the qualification criteria for the test assembly. Nevertheless, cumulative filter efficiencies of multistage systems of fine filters can be calculated by using the methods described in ISO 16890-1.
This document refers to static (barrier) filter systems but can also be applied to other filter types and systems in appropriate circumstances, for example to evaluate the initial efficiency of cleanable and surface loading filters.
The performance results obtained in accordance with this document cannot be quantitatively applied (by themselves) to predict performance in service with regard to efficiency and lifetime.

Ansaugfiltersysteme von Rotationsmaschinen - Prüfverfahren - Teil 1: Statische Filterelemente (ISO 29461-1:2021)

Dieses Dokument legt Prüfverfahren für die Ermittlung der Leistung von Partikelluftfiltern für den Einsatz in Ansaugfiltersystemen für Rotationsmaschinen, z. B. stationäre Gasturbinen, Kompressoren und andere stationäre Verbrennungskraftmaschinen, fest. Es ist anzuwenden für Luftfilter mit einem Wirkungsgrad von 85 % oder mehr für die MPPS (EPA- und HEPA Filter), die nach ISO 29463 (alle Teile) geprüft werden, und Filter mit einem geringeren Wirkungsgrad, deren Prüfung nach ISO 16890 (alle Teile) erfolgt. Die sowohl in ISO 16890 (alle Teile) als auch in ISO 29463 (alle Teile) festgelegten Verfahren werden durch dieses Dokument angewendet und auf Luftfilter erweitert, die mit Durchflussraten im Bereich von 0,24 m3/s (850 m3/h) bis zu 2,36 m3/s (8 500 m3/h) betrieben werden.
Statische Filtersysteme verwenden üblicherweise mehrere Stufen grober, feiner und optional EPA- oder HEPA Filterelemente zum Schutz der Maschinen. Der Anwendungsbereich dieses Dokuments beinhaltet Verfahren zur Leistungsprüfung individueller Filterelemente. Nicht enthalten sind Verfahren für die direkte Messung der Leistung von gesamten Systemen, wie sie im Betrieb installiert sind, ausgenommen die Fälle, in denen die Qualifikationskriterien für den Prüfaufbau erfüllt werden können. Nichtsdestotrotz können kumulative Filterwirkungsgrade mehrstufiger Systeme von Feinfiltern mit den in ISO 16890 1 festgelegten Verfahren berechnet werden.
Dieses Dokument bezieht sich auf statische (Barriere-)Filtersysteme, kann aber auch unter geeigneten Umständen auf andere Filtertypen und Systeme angewendet werden, z. B. um den Ausgangswirkungsgrad von reinigbaren und Oberflächenfiltern zu bewerten.
Die nach diesem Dokument für die Leistung ermittelten Ergebnisse können nicht unmittelbar zur quantitativen Vorhersage der Leistung bezogen auf Wirkungsgrad und Lebensdauer für den jeweiligen Anwendungsfall des Filters verwendet werden.

Systèmes de filtration d'air d'admission pour machines tournantes - Méthodes d'essai - Partie 1: Éléments filtrants pour filtres statiques (ISO 29461-1:2021)

Le présent document spécifie des méthodes et modes opératoires pour la détermination de la performance statique des filtres à air pour l’élimination des particules utilisés dans les systèmes de filtration d’air d’admission pour les machines tournantes telles que les turbines à gaz fixes, les compresseurs et autres moteurs à combustion interne fixes. Il s’applique aux filtres à air avec une efficacité de 85 % ou plus pour la MPPS (filtres EPA et HEPA) qui sont soumis à essai selon l’ISO 29463 (toutes les parties) et aux filtres avec une efficacité inférieure qui sont soumis à essai selon l’ISO 16890 (toutes les parties). Les modes opératoires décrits dans l’ISO 16890 (toutes les parties) et dans l’ISO 29463 (toutes les parties) sont appliqués et étendus par le présent document aux filtres à air fonctionnant à des débits compris dans la plage de 0,24 m3/s (850 m3/h) à 2,36 m3/s (8 500 m3/h).
Les systèmes de filtres statiques utilisent généralement plusieurs étages d'éléments filtrants grossiers, fins et, en option, EPA ou HEPA pour protéger les machines. Le domaine d'application du présent document inclut des méthodes pour les essais de performance des éléments filtrants individuels. Il n’inclut pas les méthodes pour une mesure directe des performances des systèmes dans leur totalité tels qu'installés en service sauf dans les cas où ils peuvent répondre aux critères de qualification du montage d'essai. Néanmoins, les efficacités cumulées des filtres des systèmes multi-étages de filtres fins peuvent être calculées en utilisant les méthodes décrites dans l’ISO 16890-1.
Le présent document concerne les systèmes de filtration (barrière) statiques mais peut aussi s’appliquer à d’autres types de filtres et systèmes de filtration dans des circonstances appropriées, par exemple pour évaluer l’efficacité initiale de filtres nettoyables et à chargement superficiel.
Les résultats de performance obtenus conformément au présent document ne peuvent pas être utilisés quantitativement (par eux-mêmes) pour prédire les performances en service en termes d’efficacité et de durée de vie.

Zračni filtrski sistemi rotacijskih strojev - Preskusne metode - 1. del: Statični filtrski elementi (ISO 29461-1:2021)

General Information

• Status: Published
• Public Enquiry End Date: 17-Jan-2021
• Publication Date: 14-Oct-2021
• ICS: 29.160.99 - Other standards related to rotating machinery
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 13-Oct-2021
• Due Date: 18-Dec-2021
• Completion Date: 15-Oct-2021
• Ref Project: EN ISO 29461-1:2021 - Air intake filter systems for rotary machinery - Test methods - Part 1: Static filter elements (ISO 29461-1:2021)

Relations

• Replaces: SIST EN ISO 29461-1:2013 - Air intake filter systems for rotary machinery - Test methods - Part 1: Static filter elements (ISO 29461-1:2013)
• Effective Date: 13-Oct-2021

Overview

EN ISO 29461-1:2021 - “Air intake filter systems for rotary machinery - Test methods - Part 1: Static filter elements” - specifies laboratory methods for determining the static (barrier) performance of particulate air filters used in air intake systems for rotary machinery (e.g., stationary gas turbines, compressors and stationary internal combustion engines). The standard applies test procedures from ISO 16890 and ISO 29463, extended to filters operating at flow rates between 0.24 m3/s (850 m3/h) and 2.36 m3/s (8 500 m3/h). It covers individual filter element testing, classification and reporting of results, but does not by itself quantitatively predict in-service lifetime or field efficiency.

Key Topics and Requirements

• Scope and applicability: Static filter elements (barrier filters); can be used to evaluate initial efficiency of some cleanable or surface-loading filters in suitable circumstances.
• Test method selection:
  • Filters with MPPS efficiency ≥ 85% (EPA/HEPA range) → tested per ISO 29463 series.
  • Filters with lower efficiencies → tested per ISO 16890 series.
• Flow rate range: Test procedures extended for 0.24–2.36 m3/s (850–8 500 m3/h).
• Performance measurements:
  • Fractional and overall particulate efficiency (including MPPS).
  • Airflow resistance versus captured dust mass.
  • Conditioning methods to determine minimum fractional test efficiency.
• Classification and reporting: Includes classification table and mandatory reporting elements to ensure consistent comparison of filter elements.
• Limitations: Results do not directly predict operational lifetime or field performance; whole-system performance as installed is outside scope unless the test assembly meets qualification criteria.

Applications and Users

Who benefits from EN ISO 29461-1:2021:

• Filter manufacturers - product development, performance claims and independent testing.
• OEMs and system integrators - specifying intake filtration for gas turbines, compressors and stationary engines.
• Power plant and industrial operators - comparative evaluation for procurement and maintenance planning.
• Test laboratories and certification bodies - repeatable, standardized test methods for static filter elements. Practical uses include selecting filter media and multistage configurations, sizing replacement elements, and supporting procurement specifications where laboratory-measured efficiencies and resistance data are required.

Related Standards

• ISO 16890 (all parts) - Air filters for general ventilation; classification by particle-size efficiency.
• ISO 29463 (all parts) - High-efficiency (EPA/HEPA) filter and media test methods.
• ISO 15957 - Test dusts for evaluating air cleaning equipment.
• ISO 29464 - Cleaning of air and other gases - Terminology.

EN ISO 29461-1:2021 provides standardized, laboratory-level test methods to compare and classify static intake filter elements for rotary machinery, helping stakeholders make evidence-based filtration choices while recognizing the limitations in predicting in-service behaviour.

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2021
Nadomešča:
SIST EN ISO 29461-1:2013
Zračni filtrski sistemi rotacijskih strojev - Preskusne metode - 1. del: Statični
filtrski elementi (ISO 29461-1:2021)
Air intake filter systems for rotary machinery - Test methods - Part 1: Static filter elements
(ISO 29461-1:2021)
Ansaugfiltersysteme von Rotationsmaschinen - Prüfverfahren - Teil 1: Statische
Filterelemente (ISO 29461-1:2021)
Systèmes de filtration d'air d'admission pour machines tournantes - Méthodes d'essai -
Partie 1: Éléments filtrants pour filtres statiques (ISO 29461-1:2021)
Ta slovenski standard je istoveten z: EN ISO 29461-1:2021
ICS:
29.160.99 Drugi standardi v zvezi z Other standards related to
rotacijskimi stroji rotating machinery
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 29461-1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2021
EUROPÄISCHE NORM
ICS 29.160.99 Supersedes EN ISO 29461-1:2013
English Version
Air intake filter systems for rotary machinery - Test
methods - Part 1: Static filter elements (ISO 29461-
1:2021)
Systèmes de filtration d'air d'admission pour machines Ansaugfiltersysteme von Rotationsmaschinen -
tournantes - Méthodes d'essai - Partie 1: Éléments Prüfverfahren - Teil 1: Statische Filterelemente (ISO
filtrants pour filtres statiques (ISO 29461-1:2021) 29461-1:2021)
This European Standard was approved by CEN on 13 July 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 29461-1:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 29461-1:2021) has been prepared by Technical Committee ISO/TC 142
"Cleaning equipment for air and other gases" in collaboration with Technical Committee CEN/TC 195
“Cleaning equipment for air and other gases” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2022, and conflicting national standards shall be
withdrawn at the latest by April 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 29461-1:2013.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 29461-1:2021 has been approved by CEN as EN ISO 29461-1:2021 without any
modification.
INTERNATIONAL ISO
STANDARD 29461-1
Second edition
2021-09
Air intake filter systems for rotary
machinery — Test methods —
Part 1:
Static filter elements
Systèmes de filtration d'air d'admission pour machines tournantes —
Méthodes d'essai —
Partie 1: Éléments filtrants pour filtres statiques
Reference number
ISO 29461-1:2021(E)
©
ISO 2021
ISO 29461-1:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

ISO 29461-1:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Testing and classification of filter efficiencies . 2
6 Determination of the air flow resistance versus the mass of test dust captured .4
7 Conditioning method to determine the minimum fractional test efficiency .5
8 Reporting . 5
Annex A (normative) Net area calculation . 7
Bibliography .15
ISO 29461-1:2021(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 142, Cleaning equipment for air and other
gases, in collaboration with the European Committee for Standardization (CEN) Technical Committee
CEN/TC 195, Cleaning equipment for air and other gases, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 29461-1:2013), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— a new test method, referring to ISO 16890 (all parts) and ISO 29463 (all parts), has been added;
— a classification table has been added;
— previous Annexes A, B, C and D have been deleted; previous Annex E has become Annex A.
A list of all parts in the ISO 29461 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

ISO 29461-1:2021(E)
Introduction
In rotating machinery applications, the filtering systems, typically a set of filter elements arranged in
a suitable manner, are an important part of the whole turbine/compressor system. The development
of turbine machinery used for energy production or others has led to more sophisticated equipment;
and therefore the importance of good protection of these systems has become more important in the
recent years. It is known that particulate contamination can deteriorate a turbine power system quite
substantially if not taken care of.
This event is often described as “erosion”, “fouling” and “hot corrosion” where salt and other corrosive
particles are known as potential problems. Other particulate matters can also cause significant
reduction of efficiency of the systems. It is important to understand that air filter devices in such systems
are located in various environmental conditions. The range of climate and particulate contamination is
very wide, ranging from deserts to humid rain forests to arctic environments. The requirements on
these filter systems are obviously different depending on where they will be operating.
ISO 29461 (all parts) has based the performance of the air intake filter systems not only upon heavy
dust collection but also particulate efficiency in a size range that is considered to be the problematic
area for these applications. Both ultra-fine and fine particles, as well as larger particles, should be
considered when evaluating turbine fouling. In typical outdoor air, ultra-fine and fine particles in the
size range from 0,01 μm to 1 μm contribute to > 99 % of the number concentration and to > 90 % of the
surface contamination. The majority of the mass normally comes from larger particles (>1,0 μm).
Turbo-machinery filters comprise a wide range of products from filters for very coarse particles to
filters for very fine, sub-micron particles. The range of products varies from depth to surface loading
systems, which can be regenerated e.g. by pulse cleaning. The filters and the systems have to withstand
a wide temperature and humidity range, very low to very high dust concentration and mechanical
stress. The shape of products existing today can be of many different types and have different functions
such as droplet separators, coalescing products, filter pads, metal filters, inertial filters, filter cells,
bag filters, panel-type, cleanable and depth loading filter cartridges and pleated media surface filter
elements.
ISO 29461 (all parts) provides a way to compare these products in a similar way and define what
criteria are important for air filter intake systems for rotary machinery performance protection.
The aim is to compare different filters and filter types with respect to the operating conditions they
finally will be used in. For instance, if a filter or a filter system is meant to operate in an extreme, very
dusty environment, the real particulate efficiency of such a filter cannot be predicted because the dust
loading of the filter plays an important role. A further part of ISO 29461 will address the performance
of cleanable and surface loading filters. Filters in turbo-machinery applications can also face very harsh
operating conditions such as high air flow rates or water and salt ingress. Further parts of ISO 29461
will address the performance of filters under such harsh conditions.
INTERNATIONAL STANDARD ISO 29461-1:2021(E)
Air intake filter systems for rotary machinery — Test
methods —
Part 1:
Static filter elements
1 Scope
This document specifies methods and procedures for determining the static performance of particulate
air filters used in air intake filter systems for rotary machinery such as stationary gas turbines,
compressors and other stationary internal combustion engines. It applies to air filters with an efficiency
of 85 % or more for the MPPS (EPA and HEPA filters) which are tested according to ISO 29463 (all parts)
and filters with a lower efficiency which are tested according to ISO 16890 (all parts). The procedures
described in both ISO 16890 (all parts) and ISO 29463 (all parts) are applied and extended by this
3 3
document to air filters which operate at flow rates within the range 0,24 m /s (850 m /h) up to
3 3
2,36 m /s (8 500 m /h).
Static filter systems normally use multiple stages of coarse, fine and optional EPA or HEPA filter elements
to protect the machinery. The scope of this document includes methods for performance testing of
individual filter elements. It does not include methods for the direct measurement of the performance
of entire systems as installed in service except in cases where they can meet the qualification criteria
for the test assembly. Nevertheless, cumulative filter efficiencies of multistage systems of fine filters
can be calculated by using the methods described in ISO 16890-1.
This document refers to static (barrier) filter systems but can also be applied to other filter types and
systems in appropriate circumstances, for example to evaluate the initial efficiency of cleanable and
surface loading filters.
The performance results obtained in accordance with this document cannot be quantitatively applied
(by themselves) to predict performance in service with regard to efficiency and lifetime.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 15957, Test dusts for evaluating air cleaning equipment
ISO 16890 (all parts), — Air filters for general ventilation
ISO 29463 (all parts), — High efficiency filters and filter media for removing particles from air
ISO 29464, Cleaning of air and other gases — Terminology
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29464 and the following
apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
ISO 29461-1:2021(E)
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
EPA filter
efficient particulate air filter
filters with performance complying with requirements of filter class ISO T10 to ISO T12 as per this
document
Note 1 to entry: EPA filters cannot be and shall not be leak tested.
3.2
initial gravimetric arrestance
A
ratio of the mass of a standard test dust retained by the filter to the mass of dust fed after the first 100 g
of dust load
Note 1 to entry: This measure is expressed as a weight percentage.
4 Symbols and abbreviated terms
For the application of this document, the following symbols and abbreviated terms apply:
ePM Minimum efficiency value with x = 1 µm, 2,5 µm or 10 µm of the conditioned filter element,
x, min
% (see ISO 16890-1)
ePM Efficiency with x = 1 µm, 2,5 µm or 10 µm, % (see ISO 16890-1)
x
MPPS Most penetrating particle size
5 Testing and classification of filter efficiencies
Filters with an efficiency of 85 % or more for the MPPS (EPA and HEPA filters) shall be tested
according to ISO 29463 (all parts), while filters with a lower efficiency shall be tested according to
ISO 16890 (all parts). Filters are classified in groups and classes based on their efficiency as defined in
Table 1.
NOTE For the classification of ISO ePM and
...