SIST EN 549:2019
(Main)Rubber materials for seals and diaphragms for gas appliances and gas equipment
Rubber materials for seals and diaphragms for gas appliances and gas equipment
This standard specifies requirements and associated test methods for rubber materials used in gas installations, gas equipment and gas appliances in contact with 1st, 2nd and 3rd family combustible gases as classified in EN 437 e.g. natural gas, LPG, bio methane bio LPG. It also establishes a classification based on temperature range and hardness. This standard is applicable to materials from which are manufactured homogeneous seals and homogeneous or reinforced diaphragms.
Since the dimensions and shape of the components differ from those of standard test pieces taken from sheet material as used for type testing of the rubber materials according to this standard, tolerances have been made in the requirements specified by Annex A for the components with respect to those specified for standard test pieces.
The range of operating temperatures covered by this standard is - 40 °C to + 150 °C.
This standard is not applicable for silicone rubber used either above 200 hPa (200 mbar) nominal pressure or at temperatures below 0 °C with 3rd family gases, as there is the possibility of condensation.
Elastomer-Werkstoffe für Dichtungen und Membranen in Gasgeräten und Gasanlagen
Diese Norm legt Anforderungen und zugehörige Prüfverfahren für Elastomer-Werkstoffe fest, die in Gasgeräte und Gasanlagen in Kontakt mit Brenngasen der 1., 2. und 3. Gasfamilie, wie in EN 437 klassifiziert z. B. Erdgas, Flüssiggas, Bio-Erdgas und Bio-Flüssiggas, eingesetzt werden. Sie stellt außerdem eine Klassifizierung nach Temperaturbereich und Härte auf. Diese Norm gilt für Werkstoffe, aus denen homogene Dichtungen und homogene oder verstärkte Membranen hergestellt werden.
Da die Abmessungen und die Form der Fertigteile von denen genormter Probekörper, hergestellt aus Plattenmaterial, wie sie zur Typprüfung von Elastomer-Werkstoffen nach dieser Norm verwendet werden, abweichen, wurden größere Toleranzen in den für Fertigteile in Anhang A festgelegten Anforderungen gegenüber den für Normprobekörper festgelegten Anforderungen eingeräumt.
Der Bereich der Betriebstemperaturen, der von dieser Norm abgedeckt wird, reicht von − 40 °C bis + 150 °C.
Diese Norm gilt weder für den Einsatz von Silikongummi bei Nenndruck über 200 hPa (200 mbar) noch bei Temperaturen unter 0 °C in Kontakt mit Gasen der 3. Gasfamilie, da unter diesen Umständen Kondensation möglich ist.
Matériaux à base de caoutchouc pour joints d'étanchéité et membranes destinés aux appareils à gaz et appareillages pour le gaz
La présente norme définit les exigences et les méthodes d'essai associées relatives aux matériaux en caoutchouc utilisés dans les installations, appareils d'utilisation et équipement de gaz en contact avec les combustibles gazeux de première, deuxième ou troisième famille selon la classification de l'EN 437, par exemple, gaz naturel, GPL, biométhane, bio GPL. Elle établit également une classification basée sur une gamme de températures et de duretés. La présente norme est applicable aux matériaux à partir desquels sont fabriqués les joints d’étanchéité homogènes et les membranes homogènes ou renforcées.
Étant donné que les dimensions et la forme des pièces diffèrent de celles des éprouvettes normalisées prélevées dans des plaques du matériau et utilisées pour les essais de type des matériaux en caoutchouc au sens de la présente norme, des tolérances ont été apportées aux exigences spécifiées pour les pièces, à l'Annexe A, par rapport à celles spécifiées pour les éprouvettes normalisées.
La gamme de températures de service couverte par la présente norme est de - 40 °C à + 150 °C.
La présente norme n'est pas applicable au caoutchouc silicone utilisé au-dessus d'une pression nominale de 200 hPa (200 mbar) ou à des températures inférieures à 0 °C avec la troisième famille de gaz, car il y a possibilité de condensation.
Gumeni materiali za tesnila in membrane v plinskih aparatih in plinskih napravah
Ta standard določa zahteve in z njimi povezane preskusne metode za gumene materiale, ki se uporabljajo v plinskih napravah, plinski opremi in plinskih aparatih v stiku z vnetljivimi plini razredov 1, 2 in 3, razvrščenimi v skladu s standardom EN 437, npr. zemeljski plin, utekočinjeni naftni plin, bioplin, bio-metan. Vzpostavlja tudi razvrstitev glede na temperaturno območje delovanja in trdoto. Ta standard se uporablja za materiale, iz katerih so izdelana homogena tesnila in homogene ali ojačane membrane.
Ker se mere in oblika komponent razlikujejo od standardnih preskušancev iz plastnega materiala, ki se uporabljajo za preskušanje tipa gumenih materialov v skladu s tem standardom, so bila v delih, določenih v dodatku A, določena dovoljena odstopanja za komponente glede na tiste, ki veljajo za standardne preskušance.
Temperaturno območje delovanja, ki ga zajema ta standard, je od –40 do 150 °C.
Ta standard se ne uporablja za silikonsko gumo, ki se uporablja bodisi pri nominalnem tlaku nad 200 hPa (200 mbar) bodisi pri temperaturah pod 0 °C s plini razreda 3, saj obstaja možnost kondenzacije.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 549:2019
01-september-2019
Nadomešča:
SIST EN 549:1996
Gumeni materiali za tesnila in membrane v plinskih aparatih in plinskih napravah
Rubber materials for seals and diaphragms for gas appliances and gas equipment
Elastomer-Werkstoffe für Dichtungen und Membranen in Gasgeräten und Gasanlagen
Matériaux à base de caoutchouc pour joints d'étanchéité et membranes destinés aux
appareils à gaz et appareillages pour le gaz
Ta slovenski standard je istoveten z: EN 549:2019
ICS:
83.140.50 Tesnila Seals
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
SIST EN 549:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 549:2019
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SIST EN 549:2019
EN 549
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2019
EUROPÄISCHE NORM
ICS 83.140.50 Supersedes EN 549:1994
English Version
Rubber materials for seals and diaphragms for gas
appliances and gas equipment
Matériaux à base de caoutchouc pour joints Elastomer-Werkstoffe für Dichtungen und Membranen
d'étanchéité et membranes destinés aux appareils à in Gasgeräten und Gasanlagen
gaz et matériels pour le gaz
This European Standard was approved by CEN on 22 April 2019.
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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 549:2019 E
worldwide for CEN national Members.
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SIST EN 549:2019
EN 549:2019 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Product's information . 7
5 Classification . 8
6 Requirements . 9
6.1 General . 9
6.2 Requirements for rubber material used to manufacture seals . 9
6.3 Requirements for rubber material used to manufacture diaphragms . 10
7 Test methods . 12
7.1 General . 12
7.2 Hardness . 12
7.3 Tensile strength and elongation at break . 12
7.4 Compression set . 12
7.5 Resistance to ageing . 12
7.6 Resistance to gas . 12
7.7 Resistance to condensate/liquid phase of combustible gases . 13
7.8 Resistance to lubricants . 13
7.9 Resistance to ozone . 13
8 Evaluation of life-time for material used to manufacture seals . 15
9 Infrared spectra of the material . 16
Annex A (normative) Requirements and test of components . 17
A.1 Scope . 17
A.2 Requirements . 17
A.2.1 General . 17
A.2.2 Physical and chemical properties of seals . 17
A.2.3 Physical and chemical properties of diaphragms . 17
A.3 Tests methods for components . 17
A.3.1 General . 17
A.3.2 Hardness . 17
A.3.3 Resistance to ageing . 18
A.3.4 Resistance to gas . 18
A.3.5 Resistance to condensate/liquid phase of combustible gas . 18
A.3.6 Resistance to lubricants . 18
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A.3.7 Resistance to ozone . 19
Annex B (normative) Infrared spectra of the material . 23
B.1 Scope . 23
B.2 Requirements . 23
B.2.1 General . 23
B.2.2 Solvent extract . 23
B.2.3 Infrared spectra . 23
B.2.4 Density . 23
B.3 Methods of test . 23
B.3.1 General . 23
B.3.2 Solvent extraction . 23
B.3.3 Infrared spectra . 24
B.3.4 Density . 24
Annex C (normative) Evaluation of lifetime for material used to manufacture seals by using
the compression set method . 25
C.1 General . 25
C.2 Requirements . 26
C.3 Test Procedure . 26
C.4 Evaluation of Test Results . 27
C.5 Documentation . 28
Annex D (informative) Verification of identity of material . 29
D.1 Scope . 29
D.2 Verification requirements . 29
D.2.1 General . 29
D.2.2 Solvent extract . 29
D.2.3 Infrared spectra . 29
D.2.4 Density . 29
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Regulation 2016/426 aimed to be covered . 30
Bibliography . 31
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EN 549:2019 (E)
European foreword
This document (EN 549:2019) has been prepared by Technical Committee CEN/TC 208 “Elastomeric
seals for joints in pipework and pipelines”, the secretariat of which is held by BSI.
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 January 2020, and conflicting national standards shall
be withdrawn at the latest by January 2020.
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 549:1994.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Regulation 2016/426
relating to appliances burning gaseous fuels.
For relationship with EU Regulation 2016/426, see informative Annex ZA, which is an integral part of this
document.
The following main technical changes have been made compared to EN 549:1994:
a) Clause 8, “Evaluation of life-time for material used to manufacture seals” added;
b) Clause 9, “Infrared spectra of the material” added;
c) resistance to condensate/liquid phase of combustible gases added;
d) low temperature classes added;
e) ozone resistance for diaphragms is now mandatory;
f) informative Annex D added.
NOTE Verification of identity of material is described in the informative Annex D.
According to the CEN-CENELEC Internal Regulations, the national standards organisations 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.
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EN 549:2019 (E)
Introduction
This document specifies the requirements for rubber materials to be used for the manufacture of seals
and diaphragms. It specifies for that purpose, tests to be carried out on standardized test pieces taken
from sheets of material, since the small size of most components in general does not allow the preparation
of necessary test samples for carrying out the complete range of tests.
It may be necessary to carry out supplementary tests on the component mounted in the gas appliance or
in equipment, to confirm the functional suitability of the component. Such tests should be performed
under the most severe service conditions envisaged in the appropriate standards for the gas appliances
and/or equipment.
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EN 549:2019 (E)
1 Scope
This document specifies requirements and associated test methods for rubber materials used in gas
installations, gas equipment and gas appliances in contact with 1st, 2nd and 3rd family combustible gases
as classified in EN 437:2018, additionally LPG, bio methane and bio LPG, in the same quality, are covered.
It also establishes a classification based on temperature range and hardness. This document is applicable
to materials from which homogeneous seals and homogeneous or reinforced diaphragms are
manufactured.
Since the dimensions and shape of the components differ from those of standard test pieces taken from
sheet material as used for type testing of the rubber materials according to this document, tolerances
have been made in the requirements specified by Annex A for the components with respect to those
specified for standard test pieces.
The range of operating temperatures covered by this document is –40 °C to +150 °C.
For applications with potential condensation, this document is not applicable for silicon rubber, e.g. above
200 hPa (200 mbar) nominal pressure or at temperatures below 0 °C with 3rd family gases.
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.
EN ISO 1183-1:2019, Plastics - Methods for determining the density of non-cellular plastics - Part 1:
Immersion method, liquid pycnometer method and titration method (ISO 1183-1:2019)
ISO 37:2017, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 48-2:2018, Rubber, vulcanized or thermoplastic — Determination of hardness – Part 2: Hardness
between 10 IRHD and 100 IRHD
ISO 188:2011, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests
ISO 815-1:2014, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At
ambient or elevated temperatures
ISO 815-2:2014, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 2: At low
temperatures
ISO 1407:2011, Rubber — Determination of solvent extract
ISO 1431-1:2012, Rubber, vulcanized or thermoplastic — Resistance to ozone cracking — Part 1: Static and
dynamic strain testing
ISO 1817:2015, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 4650:2012, Rubber — Identification — Infrared spectrometric methods
ISO 23529:2016, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods
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EN 549:2019 (E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
rubber material
vulcanised mixture of rubber and ingredients used to manufacture rubber material
3.2
component
finished product manufactured from rubber material
Note 1 to entry For example. O-Rings, diaphragms, …
3.3
seal
component used as an interface between parts of a gas appliance or parts of gas equipment to ensure gas
tightness
3.4
diaphragm
component located in a fixture and serving as a flexible gas tight partition between two chambers
3.5
reinforcement
material arranged in or on the elastomeric material, thus reinforcing certain properties of such
Note 1 to entry: For example, the bursting strength of diaphragms.
3.6
rubber compound
mixture of raw rubber and ingredients used to manufacture rubber material
4 Product's information
The following information shall be documented:
— a unique rubber material reference;
— the nominal hardness;
— the maximum working temperature;
— the minimum working temperature;
— whether the material is resistant to ozone;
— whether the material is resistant to condensate/liquid phase of combustible gas;
— for reinforced material, a full specification of the reinforcement, including at least:
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EN 549:2019 (E)
— type of material (for example polyester, nylon, cotton or silk);
2
— grammage (g/m );
— yarn type;
— basic construction;
— yarn count in warp and weft;
— yarn twist.
Diaphragms shall be ozone resistant. Due to the potential risk of damage of any protective surface coating,
such as waxes, by dynamic flexing such methods of protection against ozone attack shall not be used
without additional protective additives.
5 Classification
Materials shall be classified according to temperature range and hardness as given in Table 1 and Table 2
respectively.
Table 1 — Temperature classes
Range of operating temperature (°C)
Class
from to
A1 0 60
B1 0 80
C1 0 100
D1 0 125
E1 0 150
A2 −20 60
B2 −20 80
C2 −20 100
D2 −20 125
E2 −20 150
A3 −30 60
B3 −30 80
C3 −30 100
D3 −30 125
E3 −30 150
A4 −40 60
B4 −40 80
C4 −40 100
D4 −40 125
E4 −40 150
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Table 2 — Hardness classes
Class H1 H2 H3
Nominal
hardness range
< 45 45 to 60 > 60 to 90
(IRHD-M)
EXAMPLE The classification of a rubber material applicable over the temperature range of –20 °C to +80 °C
with a declared nominal hardness of 70 IRHD-M would be B2/H3.
6 Requirements
6.1 General
Test pieces shall be free from internal and external defects such as porosity, inclusion, blisters and surface
imperfections visible to the naked eye.
6.2 Requirements for rubber material used to manufacture seals
When tested in accordance with the methods detailed in Clause 7 standard test pieces shall be used. The
material shall comply with the requirements given in Table 3.
Table 3 — Requirements for rubber material used to manufacture seals
Hardness class
Property Unit
H1 H2 H3
Hardness
Tolerance on stated nominal hardness IRHD-M ±5 ±5 ±5
Tensile strength MPa ≥ 5 ≥ 7 ≥ 7
Elongation at break % ≥ 125 ≥ 125 ≥ 125
Compression set
a % ≤ 40 ≤ 40 ≤ 40
— at high temperature
— at low temperature 0 °C % ≤ 40 ≤ 40 ≤ 40
— at low temperature −20 °C % ≤ 50 ≤ 50 ≤ 50
— at low temperature −30 °C % ≤ 70 ≤ 70 ≤ 70
— at low temperature −40 °C % ≤ 75 ≤ 75 ≤ 75
Resistance to ageing
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in tensile strength, max. % − 40 − 40 − 40
— change in elongation at break, max. % − 40 − 40 − 40
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Hardness class
Property Unit
H1 H2 H3
b
Resistance to gas
— change in mass after immersion, max. %
+10 +10 +10
−5 −5 −5
— change in mass after drying, max. %
+5 +5 +5
−8 −8 −8
Resistance to condensate/liquid phase of
c
combustible gases
— change in mass after immersion, max. % + 20 + 20 + 20
— change in mass after drying, max. % − 15 − 12 − 10
d
Resistance to lubricant
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in mass, max. %
+15 +15 +15
−10 −10 −10
e no cracks
Resistance to ozone
a
The test piece shall not be damaged by adhering to the surface of the test apparatus.
b
For silicone material there is no requirement for change in mass after immersion as swelling by some such
materials may be substantial, the requirement for change in mass after drying, is ± 5 %.
c
This requirement is only applicable if the material has been declared as resistant to condensate/liquid phase
of combustible gases
+10
d
For silicone material the requirement for change in hardness and mass are ± 15 IRHD and % respectively.
-1
e
This requirement is only applicable if the material has been declared to be ozone resistant.
6.3 Requirements for rubber material used to manufacture diaphragms
When tested in accordance with the methods detailed in Clause 7standard test pieces shall be used.
The material used to manufacture diaphragms shall comply with the requirements given in Table 4.
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Table 4 — Requirements for rubber material used to manufacture diaphragms
Hardness class
Property Unit
H1 H2 H3
Hardness
Tolerance on stated nominal hardness IRHD-M ±5 ±5 ±5
Tensile strength MPa ≥ 5 ≥ 7 ≥ 10
Elongation at break % ≥ 500 ≥ 300 ≥ 200
a
Compression set
— at high temperature % ≤ 35 ≤ 25 ≤ 25
— at low temperature 0 °C % ≤ 40 ≤ 40 ≤ 40
— at low temperature – 20 °C % ≤ 50 ≤ 50 ≤ 50
— at low temperature – 30 °C % ≤ 70 ≤ 70 ≤ 70
— at low temperature – 40 °C % ≤ 75 ≤ 75 ≤ 75
Resistance to ageing
— change in hardness, max. IRHD-M ±8 ±8 ±8
— change in tensile strength, max. % − 15 − 15 − 15
— change in elongation at break, max. % − 25 − 25 − 25
b
Resistance to gas
— change in mass after immersion, max. % ±10
+10 +10
−5 −5
— change in mass after drying, max. %
+5 +5 +5
−15 −10 −8
Resistance to condensate/liquid phase of combustible
c
gases
— change in mass after immersion, max. % + 20 + 20 + 20
— change in mass after drying, max. % − 15 − 12 − 10
Resistance to lubricant
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in mass, max. %
+15 +15 +15
−10 −10 −10
Resistance to ozone no cracks
a
The test piece shall not be damaged by adhering to the surface of the test apparatus.
b
This requirement excludes the use of silicone material. In some applications it may be possible to leave the
requirement for change in mass after immersion when care is taken that:
— there is no risk of formation of gas condensate in the application;
— the permeation rate is no problem in the application;
— the low tear resistance is compensated by reinforcement or construction.
c
This requirement is only applicable if the material has been declared as resistant to condensate/liquid phase
of combustible gases
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7 Test methods
7.1 General
In addition to the conditions below, Table 5 shall be considered.
Test pieces shall be cut from a sheet of material of (2 ± 0,2) mm or (6,3 ± 0,3) mm thickness as specified
in the method of test. Measurements of thickness shall be carried out as specified in ISO 23529:2016.
The material shall be from the same compound formulation used to make the component, vulcanized
under conditions which are comparable to those used in production.
7.2 Hardness
Five measurements shall be taken using ISO 48-2:2018, method M on each of three test samples of sheet
material at a test temperature of (23 ± 2) °C.
7.3 Tensile strength and elongation at break
Measurements are carried out on six dumb-bell test pieces, type 2, in accordance with the test method
given in ISO 37:2017 at a test temperature of (23 ± 2) °C.
7.4 Compression set
7.4.1 Tests at ambient or elevated temperature shall be performed on three cylindrical disc test pieces
of (13 ± 0,5) mm diameter and (6,3 ± 0,3) mm thickness in accordance with the method given in
ISO 815-1:2014. For test temperatures and durations of tests, see Table 5.
7.4.2 Tests at low temperatures shall be performed on three cylindrical disc test pieces of
(13 ± 0,5) mm diameter and (6,3 ± 0,3) mm thickness in accordance with ISO 815-2:2014. For test
temperatures and durations of tests, see Table 5.
7.5 Resistance to ageing
Dumb-bell test pieces type 2 (six for both tensile strength and elongation at break and three for hardness
testing) are tested in accordance with ISO 188:2011 using a normal air oven under the following special
conditions:
0
— duration of ageing: 168 h;
-2
— test temperature: see Table 5.
NOTE It is permissible for the hardness test to be carried out on the tensile strength test pieces before tensile
strength testing.
7.6 Resistance to gas
Three test pieces of dimension 50 mm × 20 mm × 2 mm shall be tested in accordance with
ISO 1817:2015, 7.2 using apparatus in accordance with ISO 1817:2015, 3.1 and the following special
conditions:
0
— immerse for 72 h at (23 ± 2) °C in n-pentane;
-2
NOTE 98 % minimum n-pentane by mass, measured by gas chromatography.
— after removal from the liquid, wipe dry rapidly and weigh immediately;
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— determine the change in mass with reference to the initial mass of the sample;
0
— dry the test specimens for a period of h in a normal air oven at (40 ± 2) °C;
168
-2
— determine the new change in mass with reference to the initial mass of the sample.
Calculate the arithmetic mean values of the three results both after immersion and after drying.
7.7 Resistance to condensate/liquid phase of combustible gases
Three test pieces of dimension 50 mm × 20 mm × 2 mm shall be tested in accordance with
ISO 1817:2015, 7.2 using apparatus in accordance with ISO 1817:2015, 3.1 and the following special
conditions:
0
— immerse for 72 h at (23 ± 2) °C in liquid B;
-2
— after removal from the liquid, wipe dry rapidly and weigh immediately;
— determin
...
SLOVENSKI STANDARD
oSIST prEN 549:2017
01-julij-2017
Gumeni materiali za tesnila in membrane v plinskih aparatih in plinskih napravah
Rubber materials for seals and diaphragms for gas appliances and gas equipment
Elastomer-Werkstoffe für Dichtungen und Membranen in Gasgeräten und Gasanlagen
Matériaux à base de caoutchouc pour joints d'étanchéité et membranes destinés aux
appareils à gaz et appareillages pour le gaz
Ta slovenski standard je istoveten z: prEN 549
ICS:
83.140.50 Tesnila Seals
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
oSIST prEN 549:2017 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 549:2017
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oSIST prEN 549:2017
DRAFT
EUROPEAN STANDARD
prEN 549
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2017
ICS 83.140.50 Will supersede EN 549:1994
English Version
Rubber materials for seals and diaphragms for gas
appliances and gas equipment
Matériaux à base de caoutchouc pour joints Elastomer-Werkstoffe für Dichtungen und Membranen
d'étanchéité et membranes destinés aux appareils à in Gasgeräten und Gasanlagen
gaz et appareillages pour le gaz
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 208.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 549:2017 E
worldwide for CEN national Members.
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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Product's information . 7
5 Classification . 8
6 Requirements . 9
6.1 General . 9
6.2 Physical and chemical properties of rubber materials for seals . 9
6.3 Physical and chemical properties of elastomeric materials for diaphragms . 11
7 Test methods . 12
7.1 General . 12
7.2 Hardness . 12
7.3 Tensile strength and elongation at break . 12
7.4 Compression set . 12
7.5 Resistance to ageing . 12
7.6 Resistance to gas . 12
7.7 Resistance to liquid phase of combustible gases . 13
7.8 Resistance to lubricants . 13
7.9 Resistance to ozone . 13
8 Evaluation of life-time for material used to manufacture seals . 15
Annex A (normative) Verification of components by physical and chemical testing . 16
A.1 Scope . 16
A.2 Requirements . 16
A.3 Tests methods for components . 16
Annex B (normative) Verification of identity . 22
B.1 Scope . 22
B.2 Requirements . 22
B.3 Methods of test . 22
Annex C (informative) Evaluation of life-time for material used to manufacture seals by
using the compression set method . 24
C.1 General . 24
C.2 Requirements . 25
C.3 Test Procedure . 25
C.4 Evaluation of Test Results . 25
C.5 Documentation . 27
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Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2009/142/EC aimed to be covered . 28
Bibliography . 29
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European foreword
This document (prEN 549:2017) has been prepared by Technical Committee CEN/TC 208 “Elastomeric
seals for joints in pipework and pipelines”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 549:1994.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive 2009/142/EC
relating to appliances burning gaseous fuels.
For relationship with EU Directive 2009/142/EC, see informative Annex ZA, which is an integral part of
this document.
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Introduction
This European Standard specifies the requirements for rubber materials to be used for the manufacture
of seals and diaphragms. It specifies for that purpose, tests to be carried out on standardized test pieces
taken from sheets of material, since the small size of most components does not, in general, allow for the
necessary standard samples to be prepared from them in order to undertake the complete range of tests.
It may be necessary to carry out supplementary tests on the component mounted in the gas appliance, or
in equipment, to confirm the functional suitability of the component. Such tests should be performed
under the most severe service conditions envisaged in the appropriate standards for the gas appliances
and/or equipment.
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1 Scope
This standard specifies requirements and associated test methods for rubber materials used in gas
installations, gas equipment and gas appliances in contact with 1st, 2nd and 3rd family combustible gases
as classified in EN 437 e.g. natural gas, LPG, bio methane bio LPG. It also establishes a classification based
on temperature range and hardness. This standard is applicable to materials from which are
manufactured homogeneous seals and homogeneous or reinforced diaphragms.
Since the dimensions and shape of the components differ from those of standard test pieces taken from
sheet material as used for type testing of the rubber materials according to this standard, tolerances have
been made in the requirements specified by Annex A for the components with respect to those specified
for standard test pieces.
The range of operating temperatures covered by this standard is - 40 °C to + 150 °C.
This standard is not applicable for silicone rubber used either above 200 hPa (200 mbar) nominal
pressure or at temperatures below 0 °C with 3rd family gases, as there is the possibility of condensation.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 37:2011, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
ISO 48:2010, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between
10 IRHD and 100 IRHD)
ISO 188:2011, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests
ISO 815-1:2014, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At
ambient or elevated temperatures
ISO 815-2:2014, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 2: At low
temperatures
ISO 1407:2011, Rubber — Determination of solvent extract
ISO 1431-1:2012, Rubber, vulcanized or thermoplastic — Resistance to ozone cracking — Part 1: Static and
dynamic strain testing
ISO 1817:2015, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 4650:2012, Rubber — Identification — Infrared spectrometric methods
ISO 11346:2014, Rubber, vulcanized or thermoplastic — Estimation of life-time and maximum temperature
of use
ISO 23529:2016, Rubber — General procedures for preparing and conditioning test pieces for physical test
methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
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3.1
rubber material
vulcanised rubber material
3.2
component
finished product manufactured from rubber material
Note 1 to entry: E.g. O-Rings, diaphragms, …
3.3
seal
component used as an interface between parts of a gas appliance or parts of gas equipment to ensure gas
tightness
3.4
diaphragm
component located in a fixture and serving as a flexible gas tight partition between two chambers
3.5
reinforcement
material arranged in or on the elastomeric material, thus reinforcing certain properties of such
Note 1 to entry: for example, the bursting strength of diaphragms
3.6
rubber compound
mixture of raw rubber and ingredients used to manufacture rubber material
4 Product's information
The following information shall be documented:
— a unique rubber material reference;
— the nominal hardness;
— the maximum working temperature;
— the minimum working temperature;
— whether the material is resistant to ozone;
— whether the material is resistant to liquid phase of combustible gas;
— for reinforced material, a full specification of the reinforcement, including at least:
a) type of material (polymer);
b) grammage;
c) yarn type;
d) basic construction;
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e) yarn count in warp and weft;
f) yarn twist.
It is recommended that diaphragms should be ozone resistant. Because of the potential interruption of
any protective surface coating, such as waxes, by dynamic flexing such methods of protection against
ozone attack shall not be used without additional protective additives.
5 Classification
Materials shall be classified according to temperature range and hardness as given in Table 1 and Table 2
respectively.
Table 1 — Temperature classes
Range of operating temperature (°C)
Class
from to
A1 0 60
B1 0 80
C1 0 100
D1 0 125
E1 0 150
A2 − 20 60
B2 − 20 80
C2 − 20 100
D2 − 20 125
E2 − 20 150
A3 − 30 60
B3 − 30 80
C3 − 30 100
D3 − 30 125
E3 − 30 150
A4 − 40 60
B4 − 40 80
C4 − 40 100
D4 − 40 125
E4 − 40 150
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Table 2 — Hardness classes
Class H1 H2 H3
Nominal
hardness range < 45 45 to 60 > 60 to 90
(IRHD-M)
EXAMPLE The classification of a rubber material applicable over the temperature range of – 20 °C to + 80 °C
with a declared nominal hardness of 70 IRHD-M would be B2/H3.
6 Requirements
6.1 General
Test pieces shall be free from internal and external defects such as porosity, inclusion, blisters and surface
imperfections visible to the naked eye.
6.2 Physical and chemical properties of rubber materials for seals
When tested in accordance with the methods detailed in Clause 7, using standard test pieces, the material
shall comply with the requirements given in Table 3.
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Table 3 — Requirements for rubber material used to manufacture seals
Hardness class
Property Unit
H1 H2 H3
Hardness
Tolerance on stated nominal hardness IRHD-M ±5 ±5 ±5
Tensile strength MPa ≥ 5 ≥ 7 ≥ 7
Elongation at break % ≥ 125 ≥ 125 ≥ 125
Compression set
a
% ≤ 40 ≤ 40 ≤ 40
— at high temperature
% ≤ 40 ≤ 40 ≤ 40
— at low temperature 0 °C
% ≤ 50 ≤ 50 ≤ 50
— at low temperature – 20 °C
% ≤ 70 ≤ 70 ≤ 70
— at low temperature – 30 °C
% ≤ 75 ≤ 75 ≤ 75
— at low temperature – 40 °C
Resistance to ageing
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in tensile strength, max. % − 40 – 40 – 40
— change in elongation at break, max. % – 40 – 40 – 40
b
Resistance to gas
— change in mass after immersion, max. +10 +10 +10
% −5 −5 −5
— change in mass after drying, max.
% +5 +5 +5
−8 −8 −8
e
Resistance to liquid phase of combustible gases
+35 +35 +30
— change in mass after immersion, max.
%
— change in mass after drying, max.
%
−15 −12 −10
c
Resistance to lubricant
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in mass, max. % +15 +15 +15
−10 −10 −10
d
no cracks
Resistance to ozone
a
The test piece shall not be damaged by adhering to the surface of the test apparatus.
b
For silicone material there is no requirement for change in mass after immersion as swelling by some such
materials may be substantial, the requirement for change in mass after drying, is ± 5 %.
+10
c
For silicone material the requirement for change in hardness and mass are ± 15 IRHD and % respectively.
−1
d
This requirement is only applicable if the material has been declared to be ozone resistant.
e
This requirement is only applicable if the material has been declared to be liquid phase of combustible gases
resistant
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6.3 Physical and chemical properties of elastomeric materials for diaphragms
When tested in accordance with the methods detailed in Clause 7, using standard test pieces.
The material used to manufacture diaphragms shall comply with the requirements given in Table 4.
Table 4 — Requirements for rubber material used to manufacture diaphragms
Hardness class
Property Unit
H1 H2 H3
Hardness
Tolerance on stated nominal hardness IRHD-M ±5 ±5 ±5
Tensile strength MPa ≥ 5 ≥ 7 ≥ 10
Elongation at break % ≥ 500 ≥ 300 ≥ 200
a
Compression set
— at high temperature % ≤ 35 ≤ 25 ≤ 25
— at low temperature 0 °C % ≤ 40 ≤ 40 ≤ 40
— at low temperature – 20 °C % ≤ 50 ≤ 50 ≤ 50
— at low temperature – 30 °C % ≤ 70 ≤ 70 ≤ 70
— at low temperature – 40 °C % ≤ 75 ≤ 75 ≤ 75
Resistance to ageing
— change in hardness, max. IRHD-M ±8 ±8 ±8
— change in tensile strength, max. % − 15 – 15 – 15
— change in elongation at break, max. % – 25 – 25 – 25
b
Resistance to gas
— change in mass after immersion, max. % ±10 +10 +10
−5 −5
— change in mass after drying, max. % +5
−15 +5 +5
−10 −8
c
Resistance to liquid phase of combustible gases
+35 +35 +30
— change in mass after immersion, max. %
— change in mass after drying, max. %
−15 −12 −10
Resistance to lubricant
— change in hardness, max. IRHD-M ±10 ±10 ±10
— change in mass, max. % +15 +15 +15
−10 −10 −10
Resistance to ozone no cracks
a
The test piece shall not be damaged by adhering to the surface of the test apparatus.
b
This requirement excludes the use of silicone material. In some applications it may be possible to leave the
requirement for change in mass after immersion when care is taken that:
— there is no risk of formation of gas condensate in the application;
— the permeation rate is no problem in the application;
— the low tear resistance is compensated by reinforcement or construction.
c
This requirement is only applicable if the material has been declared to be liquid phase of combustible gases
resistant
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7 Test methods
7.1 General
In addition to the conditions below reference should be made to Table 5.
Test pieces shall be cut from a sheet of material of (2 ± 0,2) mm or (6,3 ± 0,3) mm thickness as specified
in the method of test. Measurements of thickness shall be carried out as specified in ISO 23529:2016.
The material shall be from the same compound formulation used to make the component, vulcanized
under conditions which are comparable to those used in production.
7.2 Hardness
Five measurements shall be taken using ISO 48:2010, method M on each of three test samples of sheet
material at a test temperature of (23 ± 2) °C.
7.3 Tensile strength and elongation at break
Measurements are carried out on six dumb-bell test pieces, type 2, in accordance with the test method
given in ISO 37:2011 at a test temperature of (23 ± 2) °C.
7.4 Compression set
7.4.1 Tests at ambient or elevated temperature shall be performed on three cylindrical disc test pieces
of (13 ± 0,5) mm diameter and (6,3 ± 0,3) mm thickness in accordance with the method given in
ISO 815-1:2014. For test temperatures and durations of tests see Table 5.
7.4.2 Tests at low temperatures shall be performed on three cylindrical disc test pieces of
(13 ± 0,5) mm diameter and (6,3 ± 0,3) mm thickness in accordance with ISO 815-2:2014. For test
temperatures and durations of tests see Table 5.
7.5 Resistance to ageing
Dumb-bell test pieces type 2 (six for both tensile strength and elongation at break and three for hardness
testing) are tested in accordance with ISO 188:2011 using a normal air oven under the following special
conditions:
0
168
— duration of ageing: h;
−2
— test temperature: see Table 5.
It is permissible for the hardness test to be carried out on the tensile strength test pieces before tensile
strength testing.
7.6 Resistance to gas
Three test pieces of dimension 50 mm × 20 mm × 2 mm shall be tested in accordance with
ISO 1817:2015, 7.2 using apparatus in accordance with ISO 1817:2015, 3.1 and the following special
conditions:
0
— immerse for 72 h at (23 ± 2) °C in n-pentane;
−2
NOTE 98 % minimum n-pentane by mass, measured by gas chromatography.
— after removal from the liquid, wipe dry rapidly and weigh immediately;
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— determine the new change in mass with reference to the initial mass of the sample;
0
— dry the test specimens for a period of 168 h in a normal air oven at (40 ± 2) °C;
−2
— determine the new change in mass with reference to the initial mass of the sample.
Calculate the arithmetic mean values of the three results both after immersion and after drying.
7.7 Resistance to liquid phase of combustible gases
Three test pieces of dimension 50 mm × 20 mm × 2 mm shall be tested in accordance with
ISO 1817:2015, 7.2 using apparatus in accordance with ISO 1817:2015, 3.1 and the following special
conditions:
0
72
— immerse for h at (23 ± 2) °C in liquid B;
−2
— after removal from the liquid, wipe dry rapidly and weigh immediately;
— determine the new change in mass with reference to the initial mass of the sample;
0
— dry the test specimens for a period of 96 h in a normal air oven at (70 ± 2) °C;
−2
— determine the new change in mass with reference to the initial mass of the sample.
Calculate the arithmetic mean values of the three results both after immersion and after drying.
7.8 Resistance to lubricants
Three test pieces of dimensions 50 mm × 20 mm × 2 mm shall be tested in accordance with
ISO 1817:2015, 7.2 (gravimetric method) and ISO 1817:2015, 7.6 (hardness test) and the following
special conditions:
0
168
— immerse for h in oil IRM 902 at the test temperature given in Table 5;
−2
— determine the change in mass and the change in hardness with reference to that of the initial samples.
Calculate the arithmetic mean values of the results after immersion.
7.9 Resistance to ozone
Test pieces shall be tested in accordance with ISO 1431-1:2012, method A using:
0
— duration of test: 24 h;
−05,
1
— concentration of ozone: (50 ± 5) pphm by volume
— test temperature: (30 ± 2) °C;
— relative humidity < 65 %
1
pphm: parts per hundred millions, (50 ± 5) pphm = (500 ± 50) ppb.
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— elongation of test sample:
a) (20 ± 2) % for test samples with > 36 IRHD to 75 IRHD(15 ± 2) % for test samples with > 75
IRHD to 85 IRHD;
b) (10 ± 1) % for test samples with > 85 IRHD to 90 IRHD.
Table 5 — Test methods
Property Standard Test pieces Test Duration Remarks
Temperature of test
Type No.
°C
h
Hardness ISO 48:2010 — 3 23 ± 2 — —
Tensile ISO 37:2011 Dumb-bell 6 23 ± 2 — —
strength and
Type 2
elongation
at break
Compression
set
0
- at ambient ISO 815-1:2014 Cylindrical 3 Class For seals
168
−2
and elevated
disc A1 to A4: 70 ± 1
temperatures
B1 to B4: 100 ± 1
0
C1 to C4: 125 ± 1 For diaphragms
24
−05,
D1 to D4: 150 ± 2
E1 to E4: 175 ± 3
- at low ISO 815-2:2014 Cylindrical 3 A1 to E1: 0 ± 1 0 Final measurement
72
−2
temperatures disc (30 ± 3) min after
A2 to E2: −20 ± 1
dismounting at
A3 to E3: −20 ± 1
applied exposure
and −30 ± 1
temperature
A4 to E4: −20 ± 1
and −40 ± 1
Resistance ISO 188:2011 — — Class 0 Normal oven
168
−2
to ageing
A1 to A4: 70 ± 1
B1 to B4: 100 ± 1
C1 to C4: 125 ± 1
D1 to D4: 150 ± 2
E1 to E4: 175 ± 3
- hardness ISO 48:2010 Dumb-bell 3
- tensile ISO 37:2011 Type 2 6
strength and
elongation at
break
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Property Standard Test pieces Test Duration Remarks
Temperature of test
Type No.
°C
h
Resistance ISO 1817:2015, (50 × 20 × 2) 3 23 ± 2 0 Weight and
72
−2
to gas 8.2 mm determine the
change in mass.
- immersion
Use the arithmetic
in n-pentane
mean value, both
— — — 40 ± 2 0
- drying
168
−2
after immersion
and drying
Resistance ISO 1817:2015, (50 × 20 × 2) 3 23 ± 2 0 Weight and
72
−2
to liquid 8.2 mm determine the
phase of change in mass.
combustible Use the arithmetic
gas mean value, both
after immersion
- immersion — — — 70 ± 2 0
96
and drying
−2
in liquid B
- drying
Resistance ISO 1817:2015, (50 × 20 × 2) 3 Class 0 Determine the
168
−2
to lubricants (8.2 and 8.6) mm increase in mass
A1 to A4: 60 ± 1
and the change in
- immersion
B1 to B4: 80 ± 1
hardness
in oil IRM 902
C1 to C4: 100 ± 1
D1 to D4: 100 ± 1
E1 to E4: 100 ± 1
0
Resistance ISO 1431-1:2012 — 3 30 ± 2 Using an ozone
24
−05,
to ozone , Method A concentration
of (50 ± 5) pphm
elongation
(20 ± 2) % or
(15 ± 2) % or
(10 ± 1) %
8 Evaluation of life-time for material used to manufacture seals
If requirements for life-time exist, according to the use of elastomeric rubber material, evaluation of life-
time shall be achieved by different methods, e.g.
a) determination by compression set in accordance to Annex C;
b) according to ISO 11346:2014.
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Annex A
(normative)
Verification of components by physical and chemical testing
A.1 Scope
This normative annex specifies the requirements and test methods to enable the verification and quality
control to be undertaken between rubber components used in the production of gas appliances and
equipment against the previous type-tested material complying with this standard, using similar physical
and chemical test methods as those used for testing sheet material.
Since the dimensions and shape of the components differ from those of standard test pieces taken from
sheet material as used for type testing of the rubber materials according to this standard, extended
tolerances have been made in the requirements specified for the components with respect to those
specified for standard test pieces.
By conducting comparative tests on samples of similar size to that of the components taken from the
corresponding sheet material it should be possible to reduce these allowances and achieve a higher
degree of agreement.
A.2 Requirements
A.2.1 General
Components shall be free from porosity, inclusions, blisters and surface imperfections visible to the
naked eye, even after cutting. For reinforced diaphragms there shall be no sign of delamination upon
receipt nor after testing in accordance with methods laid down in this annex.
A.2.2 Physical and chemical properties of seals
When tested in accordance with the methods detailed in A.3 the component shall comply with the
requirements given in Table A.1.
A.2.3 Physical and chemical properties of diaphragms
When tested in acco
...
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