ISO 2943:1998

Hydraulic fluid power - Filter elements - Verification of material compatibility with fluids

This International Standard specifies a method of verifying the compatibility of materials comprising a hydraulic fluid power filter element with a designated fluid, by verifying the ability of the filter element to maintain its collapse burst rating after being subjected to the designated system fluid at a high and/or low temperature. The filter element mounting seal is not included as part of the element.

Transmissions hydrauliques — Éléments filtrants — Vérification de la compatibilité des matériaux avec les fluides

La présente Norme internationale spécifie une méthode de vérification de la compatibilité des matériaux composant un élément filtrant avec un fluide déterminé, qui consiste à contrôler l'aptitude de l'élément filtrant à conserver sa résistance à l'écrasement ou à l'éclatement après avoir été soumis à l'action de ce fluide à haute et/ou basse température. Les joints montés sur l'élément filtrant ne sont pas considérés comme faisant partie de cet élément

Fluidna tehnika - Hidravlika - Filtrski vložki - Potrditev združljivosti gradiv s fluidi

General Information

• Status: Published
• Publication Date: 18-Nov-1998
• ICS: 23.100.60 - Filters, seals and contamination of fluids
• Technical Committee: ISO/TC 131/SC 6 - Contamination control
• Drafting Committee: ISO/TC 131/SC 6/WG 2 - Filter and separator evaluation
• Current Stage: 9093 - International Standard confirmed
• Start Date: 24-Mar-2021
• Completion Date: 13-Dec-2025
• Ref Project: SIST ISO 2943:2000 - Hydraulic fluid power -- Filter elements -- Verification of material compatibility with fluids

Relations

• Revises: ISO 2943:1974 - Hydraulic fluid power - Filter elements - Verification of material compatibility with fluids
• Effective Date: 15-Apr-2008

Overview

ISO 2943:1998 is an international standard established by the International Organization for Standardization (ISO) that specifies a method for verifying the material compatibility of hydraulic fluid power filter elements with designated fluids. This verification ensures that the filter element maintains its structural integrity, particularly its collapse or burst strength, after exposure to specific hydraulic fluids at elevated or low temperatures. The seal mounting the filter element is excluded from this assessment.

This standard provides a practical approach to testing the resistance of filter materials in real operating conditions, highlighting the importance of fluid-material interaction in hydraulic systems. It helps manufacturers and users ensure reliable and safe hydraulic fluid filtration performance, especially under varying temperature conditions.

Key Topics

• Material Compatibility Verification
  The core function of ISO 2943:1998 is to verify that the filter element materials remain unaffected by system fluids. This involves subjecting the filter element to the specified hydraulic fluid at high and/or low temperatures to test possible deterioration or weaknesses.

• Collapse and Burst Rating Maintenance
  After exposure to the fluid, the filter must retain its collapse or burst strength as defined per ISO 2941, ensuring operational safety under pressure.

• High and Low Temperature Exposure
  The element is immersed in the fluid for at least 72 hours at 15°C above the maximum recommended operating temperature and/or 5°C below the minimum recommended temperature. This accelerated test simulates long-term exposure effects.

• Exclusion of Filter Element Seal
  The mounting seal of the filter element is explicitly excluded from the material compatibility test to focus the assessment on the filter media itself.

• Testing Procedures
  Includes preconditioning rinse steps, compliance with fabricational standards (ISO 2942), and detailed documentation and reporting requirements based on Annex A of the standard.

Applications

ISO 2943:1998 applies primarily to hydraulic fluid power systems where filters play a critical role in maintaining fluid cleanliness and protecting hydraulic components. Typical applications include:

• Hydraulic Transmission Systems
  Verifying filter element compatibility ensures sustained performance in industrial machinery, mobile equipment, and automotive hydraulic transmissions.

• Hydraulic Component Manufacturing
  Manufacturers use this standard to certify filter elements against specific fluids and operational temperatures, supporting product reliability and compliance claims.

• System Design and Maintenance
  Engineers and maintenance professionals apply this standard to select appropriate filter elements resistant to fluid conditions expected throughout the system’s service life.

• Quality Assurance
  Testing under ISO 2943:1998 supports quality control processes by validating that filter materials will not degrade prematurely when exposed to designated hydraulic fluids.

Related Standards

• ISO 2941:1974 - Hydraulic Fluid Power - Filter Elements - Verification of Collapse or Burst Resistance
  Defines the test methods related to the mechanical strength of hydraulic filter elements, which ISO 2943 references to assess post-immersion integrity.

• ISO 2942:1994 - Hydraulic Fluid Power - Filter Elements - Verification of Fabrication Compliance and Bubble Point Determination
  Specifies requirements to ensure initial filter element quality and is used as a preliminary test before compatibility verification in ISO 2943.

• ISO 5598:1985 - Fluid Power Systems and Components - Vocabulary
  Provides standardized definitions of terms used in hydraulic and pneumatic systems, ensuring clarity and consistency in communication.

Practical Value

Adhering to ISO 2943:1998 safeguards hydraulic system reliability by ensuring filter elements are compatible with the fluids they encounter, particularly under temperature extremes. This verification:

• Prevents premature failure of filters due to chemical degradation or loss of mechanical strength.
• Helps maintain fluid cleanliness and system efficiency by supporting filter longevity.
• Reduces operational risks by certifying filter elements meet robust material compatibility criteria.
• Facilitates informed procurement decisions by manufacturers and end-users based on standardized testing methods.

Manufacturers who comply with ISO 2943:1998 can confidently state the compatibility of their filter elements with designated hydraulic fluids, as recommended by the standard’s identification phrase. This boosts product transparency and supports global industry acceptance.

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Keywords: hydraulic fluid power, filter elements, material compatibility, hydraulic fluids, collapse burst rating, ISO 2943, filter testing, hydraulic system filtration, temperature exposure, fluid power standards, hydraulic filter verification.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2000
Fluidna tehnika - Hidravlika - Filtrski vložki - Potrditev združljivosti gradiv s fluidi
Hydraulic fluid power -- Filter elements -- Verification of material compatibility with fluids
Transmissions hydrauliques -- Éléments filtrants -- Vérification de la compatibilité des
matériaux avec les fluides
Ta slovenski standard je istoveten z: ISO 2943:1998
ICS:
23.100.60 )LOWULWHVQLODLQ Filters, seals and
RQHVQDåHYDQMHWHNRþLQ contamination of fluids
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 2943
Second edition
1998-11-15
Hydraulic fluid power — Filter elements —
Verification of material compatibility with
fluids
Transmissions hydrauliques — Éléments filtrants — Vérification de la
compatibilité des matériaux avec les fluides
A
Reference number
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.
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.
International Standard ISO 2943 was prepared by Technical Committee ISO/TC 131, Fluid power systems,
Subcommittee SC 6, Contamination control and hydraulic fluids.
This second edition cancels and replaces the first edition (ISO 2943:1987), which has been technically revised. It
now includes provisions for verifying material compatibility at low temperatures and a method for reporting test data.
Annex A forms an integral part of this International Standard.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
Printed in Switzerland
ii
© ISO
Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an
enclosed circuit. Filters maintain fluid cleanliness by removing insoluble contaminants.
The filter element is the porous device which performs the actual process of filtration.
iii
INTERNATIONAL STANDARD  © ISO ISO 2943:1998(E)
Hydraulic fluid power — Filter elements — Verification of material
compatibility with fluids
1 Scope
This International Standard specifies a method of verifying the compatibility of materials comprising a hydraulic fluid
power filter element with a designated fluid, by verifying the ability of the filter element to maintain its collapse burst
rating after being subjected to the designated system fluid at a high and/or low temperature.
The filter element mounting seal is not included as part of the element.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 2941:1974, Hydraulic fluid power — Filter elements — Verification of collapse/burst resistance.
ISO 2942:1994, Hydraulic fluid power — Filter elements — Verification of fabrication integrity and determination of
the first bubble point.
ISO 5598:1985, Fluid power systems and components — Vocabulary.
3 Definitions
For the purposes of this International Standard, the definitions given in ISO 5598 apply.
4 Equipment
4.1  Temperature bath or oven and cold chamber, capable of maintaining the fluid temperature to within 5 °C.
4.2  Vessel suitable for containing the fluid and test elements, closed but vented with adequate safety
considerations.
4.3  Test fluid, appropriate to the system.
4.4  Temperature instrumentation, accurate to within 1 °C.
5 Procedure
5.1  Subject the filter element to the fabrication integrity test in accordance with ISO 2942.
© ISO
Failure of the filter element to exhibit a minimum bubble pressure as designated by the filter manufacturer shall
5.2
disqualify the element from further testing.
5.3  Rinse the test element in the test fluid. The element shall be deemed to be clean if any test fluid previously
used has been removed from the test element. Discard the rinsing fluid.
5.4  Immerse the filter element in the designated system fluid for at least 72 h; the fluid shall be maintained for 72 h
continuously, at a temperature 15 °C above the manufacturer's recommended maximum operating temperature.
Use new fluid for this operation.
NOTE The 72 h soak at 15 °C above the hydraulic system manufacturer's recommended operating temperature is a
practical compromise to achieve an accelerated test rather than a long test at rated temperature.
CAUTION — Do not exceed the safe temperature of the fluid for this
...

INTERNATIONAL ISO
STANDARD 2943
Second edition
1998-11-15
Hydraulic fluid power — Filter elements —
Verification of material compatibility with
fluids
Transmissions hydrauliques — Éléments filtrants — Vérification de la
compatibilité des matériaux avec les fluides
A
Reference number
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.
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.
International Standard ISO 2943 was prepared by Technical Committee ISO/TC 131, Fluid power systems,
Subcommittee SC 6, Contamination control and hydraulic fluids.
This second edition cancels and replaces the first edition (ISO 2943:1987), which has been technically revised. It
now includes provisions for verifying material compatibility at low temperatures and a method for reporting test data.
Annex A forms an integral part of this International Standard.
©  ISO 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case postale 56 • CH-1211 Genève 20 • Switzerland
Internet [e-mail]
Printed in Switzerland
ii
© ISO
Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an
enclosed circuit. Filters maintain fluid cleanliness by removing insoluble contaminants.
The filter element is the porous device which performs the actual process of filtration.
iii
INTERNATIONAL STANDARD  © ISO ISO 2943:1998(E)
Hydraulic fluid power — Filter elements — Verification of material
compatibility with fluids
1 Scope
This International Standard specifies a method of verifying the compatibility of materials comprising a hydraulic fluid
power filter element with a designated fluid, by verifying the ability of the filter element to maintain its collapse burst
rating after being subjected to the designated system fluid at a high and/or low temperature.
The filter element mounting seal is not included as part of the element.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the editions indicated were valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
ISO 2941:1974, Hydraulic fluid power — Filter elements — Verification of collapse/burst resistance.
ISO 2942:1994, Hydraulic fluid power — Filter elements — Verification of fabrication integrity and determination of
the first bubble point.
ISO 5598:1985, Fluid power systems and components — Vocabulary.
3 Definitions
For the purposes of this International Standard, the definitions given in ISO 5598 apply.
4 Equipment
4.1  Temperature bath or oven and cold chamber, capable of maintaining the fluid temperature to within 5 °C.
4.2  Vessel suitable for containing the fluid and test elements, closed but vented with adequate safety
considerations.
4.3  Test fluid, appropriate to the system.
4.4  Temperature instrumentation, accurate to within 1 °C.
5 Procedure
5.1  Subject the filter element to the fabrication integrity test in accordance with ISO 2942.
© ISO
Failure of the filter element to exhibit a minimum bubble pressure as designated by the filter manufacturer shall
5.2
disqualify the element from further testing.
5.3  Rinse the test element in the test fluid. The element shall be deemed to be clean if any test fluid previously
used has been removed from the test element. Discard the rinsing fluid.
5.4  Immerse the filter element in the designated system fluid for at least 72 h; the fluid shall be maintained for 72 h
continuously, at a temperature 15 °C above the manufacturer's recommended maximum operating temperature.
Use new fluid for this operation.
NOTE The 72 h soak at 15 °C above the hydraulic system manufacturer's recommended operating temperature is a
practical compromise to achieve an accelerated test rather than a long test at rated temperature.
CAUTION — Do not exceed the safe temperature of the fluid for this high temperature test. This
International Standard does not apply in such cases.
5.5  If there is an additional demand for verification of material compatibility with cold fluids, rinse the element as
specified in 5.3 and then immerse the filter element in the designated system fluid for at least 72 h. The fluid shall be
maintained for 72 h continuously, at a temperature 5 °C below the stated minimum temperature of use.
Use new fluid for this operation. Use a covered container to prevent condensation.
NOTE In case of running tests on both temperature levels it might b
...

NORME ISO
INTERNATIONALE 2943
Deuxième édition
1998-11-15
Transmissions hydrauliques — Éléments
filtrants — Vérification de la compatibilité
des matériaux avec les fluides
Hydraulic fluid power — Filter elements — Verification of material
compatibility with fluids
A
Numéro de référence
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée aux
comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du comité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales, en
liaison avec l'ISO, participent également aux travaux. L'ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques sont soumis aux comités membres pour
vote. Leur publication comme Normes internationales requiert l'approbation de 75 % au moins des comités
membres votants.
La Norme internationale ISO 2943 a été élaborée par le comité technique ISO/TC 131, Transmissions hydrauliques
et pneumatiques, sous-comité SC 6, Contrôle de la contamination et fluides hydrauliques.
Cette deuxième édition annule et remplace la première édition (ISO 2943:1987), dont elle constitue une révision
technique. Elle introduit maintenant des dispositions pour la vérification de la compatibilité des matériaux à basse
température et une méthode de présentation des résultats d’essai.
L’annexe A fait partie intégrante de la présente Norme internationale.
©  ISO 1998
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous quelque
forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit de l'éditeur.
Organisation internationale de normalisation
Case postale 56 • CH-1211 Genève 20 • Suisse
Internet [e-mail]
Imprimé en Suisse
ii
© ISO
Introduction
Dans les systèmes de transmissions hydrauliques, l'énergie est transmise et commandée par l'intermédiaire d'un
liquide sous pression circulant en circuit fermé. Des filtres maintiennent la propreté du fluide en retenant les
polluants insolubles.
L'élément filtrant est le dispositif poreux par lequel s'accomplit le processus effectif de la filtration.
iii
NORME INTERNATIONALE  © ISO ISO 2943:1998(F)
Transmissions hydrauliques — Éléments filtrants —
Vérification de la compatibilité des matériaux avec les
fluides
1 Domaine d’application
La présente Norme internationale spécifie une méthode de vérification de la compatibilité des matériaux composant
un élément filtrant avec un fluide déterminé, qui consiste à contrôler l'aptitude de l'élément filtrant à conserver sa
résistance à l'écrasement ou à l'éclatement après avoir été soumis à l'action de ce fluide à haute et/ou basse
température.
Les joints montés sur l'élément filtrant ne sont pas considérés comme faisant partie de cet élément.
2 Références normatives
Les normes suivantes contiennent des dispositions qui, par suite de la référence qui en est faite, constituent des
dispositions valables pour la présente Norme internationale. Au moment de la publication, les éditions indiquées
étaient en vigueur. Toute norme est sujette à révision et les parties prenantes des accords fondés sur la présente
Norme internationale sont invitées à rechercher la possibilité d'appliquer les éditions les plus récentes des normes
indiquées ci-après. Les membres de la CEI et de l'ISO possèdent le registre des Normes internationales en vigueur
à un moment donné.
ISO 2941:1974, Transmissions hydrauliques — Éléments filtrants — Vérification de la résistance à l'écrasement ou
à l'éclatement.
ISO 2942:1994, Transmissions hydrauliques — Éléments filtrants — Vérification de la conformité de fabrication et
détermination du point de première bulle.
ISO 5598:1985, Transmissions hydrauliques et pneumatiques — Vocabulaire.
3 Définitions
Pour les besoins de la présente Norme internationale, les définitions données dans l'ISO 5598 s'appliquent.
4 Matériel
4.1  Bain thermostaté ou étuve et armoire frigorifique, pouvant maintenir la température du fluide à – 5 °C.
4.2  Récipient pouvant contenir le fluide et les éléments d'essai, fermé mais éventé dans des conditions de
sécurité appropriées.
4.3  Fluide d’essai, approprié pour le système.
4.4  Instrument de mesure de température, précis à 1 °C.
© ISO
5 Mode opératoire
5.1  Soumettre l'élément filtrant à un essai de conformité de fabrication conformément à l'ISO 2942.
5.2  Si l'élément filtrant n’atteint pas le point de bulle minimum spécifié par le fabricant du filtre, il ne doit pas être
soumis à d'autres essais.
5.3  Rincer l'élément à essayer dans le fluide d'essai. L'élément peut être considéré propre si toute trace du fluide
d'essai utilisé précédemment en a été éliminée. Jeter le fluide de rinçage.
5.4  Immerger l'élément filtrant dans le fluide indiqué pendant au moins 72 h; ce fluide doit être maintenu pendant
72 h, en continu, à une température de 15 °C au-dessus de la température maximale de fonctionnement
recommandée par le fabricant. Utiliser un fluide neuf pour cette opération.
NOTE L'immersion de 72 h à 15 °C au-dessus de la température de fonctionnement recommandée par le fabricant du
système hydraulique résulte d'un compromis pratique perme
...