Elastomeric seals - Material requirements for pipe joint seals used in water and drainage applications - Part 1: Vulcanized rubber

This standard specifies requirements of materials used for vulcanized rubber seals in:
-   Cold water (T ≤ 50 °C);
-   Cold water (T ≤ 50 °C) and intermittently hot water (T ≤ 95 °C);
-   Cold water (T ≤ 50 °C) and continuously hot water (T ≤ 110 °C).
The different designations of seals specified are defined according to their type, application and requirements (see Table 1).
This standard defines requirements for seals, partially defining the properties of the vulcanized rubber material as a performance indicator of the finished seal. Any additional requirements called for by the particular application are specified in the relevant product standards taking into account that the performance of pipe joints is a function of the seal material properties, seal geometry, pipe system material and pipe joint design. This standard should be used where appropriate with product standards which specify performance requirements for joints.
It is applicable to elastomeric components of composite or non composite seals.
In case of composite seals for materials of hardness ranges from 55 IRHD to 95 IRHD the requirements for elongation at break, compression set and stress relaxation apply only when the material is participating in the sealing function, or the long term stability of the seal.
Joint seals made with an enclosed void as part of their design are included in the scope of this European Standard.

Elastomer-Dichtungen - Werkstoff-Anforderungen für Rohrleitungs-Dichtungen für Anwendungen in der Wasserversorgung und Entwässerung - Teil 1: Elastomere

Garnitures d'étanchéité en caoutchouc - Spécification des matériaux pour garnitures d'étanchéité pour joints de canalisations utilisées dans le domaine de l'eau et de l'évacuation - Partie 1 : Caoutchouc vulcanisé

Elastomerna tesnila - Zahteve za material za tesnila za uporabo v napeljavah za vodo in kanalizacijo - 1. del: Vulkanizirana guma

General Information

Status
Not Published
Public Enquiry End Date
30-Sep-2016
Technical Committee
Current Stage
5020 - Formal vote (FV) (Adopted Project)
Start Date
10-Jul-2017
Due Date
28-Aug-2017
Completion Date
09-Aug-2017

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SLOVENSKI STANDARD
oSIST prEN 681-1:2016
01-september-2016
Elastomerna tesnila - Zahteve za material za tesnila za uporabo v napeljavah za
vodo in kanalizacijo - 1. del: Vulkanizirana guma

Elastomeric seals - Material requirements for pipe joint seals used in water and drainage

applications - Part 1: Vulcanized rubber
Elastomer-Dichtungen - Werkstoff-Anforderungen für Rohrleitungs-Dichtungen für
Anwendungen in der Wasserversorgung und Entwässerung - Teil 1: Elastomere

Garnitures d'étanchéité en caoutchouc - Spécification des matériaux pour garnitures

d'étanchéité pour joints de canalisations utilisées dans le domaine de l'eau et de

l'évacuation - Partie 1 : Caoutchouc vulcanisé
Ta slovenski standard je istoveten z: prEN 681-1
ICS:
23.040.80 Tesnila za cevne zveze Seals for pipe and hose
assemblies
oSIST prEN 681-1:2016 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 681-1:2016
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oSIST prEN 681-1:2016
DRAFT
EUROPEAN STANDARD
prEN 681-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2016
ICS 23.040.80 Will supersede EN 681-1:1996
English Version
Elastomeric seals - Material requirements for pipe joint
seals used in water and drainage applications - Part 1:
Vulcanized rubber

Garnitures d'étanchéité en caoutchouc - Spécification Elastomer-Dichtungen - Werkstoff-Anforderungen für

des matériaux pour garnitures d'étanchéité pour joints Rohrleitungs-Dichtungen für Anwendungen in der

de canalisations utilisées dans le domaine de l'eau et de Wasserversorgung und Entwässerung - Teil 1:

l'évacuation - Partie 1 : Caoutchouc vulcanisé Elastomere

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, 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

© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 681-1:2016 E

worldwide for CEN national Members.
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oSIST prEN 681-1:2016
prEN 681-1:2016 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 6

4 Application ........................................................................................................................................................ 6

5 Requirements ................................................................................................................................................... 7

5.1 Materials ............................................................................................................................................................. 7

5.1.1 General ................................................................................................................................................................ 7

5.1.2 Effect on water quality .................................................................................................................................. 7

5.1.3 Material requirements .................................................................................................................................. 8

5.2 General requirements for seal products ............................................................................................. 11

5.2.1 Dimensional tolerances ............................................................................................................................. 11

5.2.2 Imperfections and defects ......................................................................................................................... 11

6 Test methods ................................................................................................................................................. 11

6.1 Test Samples .................................................................................................................................................. 11

6.2 Test conditions .............................................................................................................................................. 12

6.3 Hardness .......................................................................................................................................................... 12

6.4 Tensile strength and elongation at break ........................................................................................... 12

6.5 Compression set in air ................................................................................................................................ 12

6.5.1 Compression set at 23 °C, 70 °C and 125 °C ......................................................................................... 12

6.5.2 Compression set at – 10 °C and – 25 °C ................................................................................................. 12

6.6 Accelerated ageing in air ........................................................................................................................... 12

6.7 Stress relaxation in compression ........................................................................................................... 12

6.8 Volume change in water ............................................................................................................................ 13

6.9 Ozone resistance .......................................................................................................................................... 13

6.10 Tear strength for joint seals for hot water supply ........................................................................... 13

6.11 Compression set in water .......................................................................................................................... 13

6.12 Strength of spliced joints ........................................................................................................................... 13

6.13 Volume change in oil ................................................................................................................................... 13

6.14 Hardness change at – 25 °C ....................................................................................................................... 13

7 Assessment and verification of constancy of performance – AVCP............................................ 14

7.1 General ............................................................................................................................................................. 14

7.2 Type testing .................................................................................................................................................... 14

7.2.1 General ............................................................................................................................................................. 14

7.2.2 Test samples, testing and compliance criteria .................................................................................. 14

7.2.3 Test reports .................................................................................................................................................... 16

7.3 Factory production control (FPC) .......................................................................................................... 16

7.3.1 General ............................................................................................................................................................. 16

7.3.2 Requirements ................................................................................................................................................ 16

7.3.3 Product specific requirements ................................................................................................................ 18

8 Designation..................................................................................................................................................... 19

9 Marking and labelling ................................................................................................................................. 19

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Annex A (normative) Determination of stress relaxation in tension ..................................................... 20

A.1 Principle ........................................................................................................................................................... 20

A.2 Apparatus ........................................................................................................................................................ 20

A.3 Test pieces ....................................................................................................................................................... 20

A.4 Test conditions .............................................................................................................................................. 20

A.5 Procedure ........................................................................................................................................................ 20

Annex B (normative) Determination of compression set in hot water at 110 °C ............................... 22

B.1 Principle ........................................................................................................................................................... 22

B.2 Apparatus ........................................................................................................................................................ 22

B.3 Test pieces ....................................................................................................................................................... 22

B.4 Procedure ........................................................................................................................................................ 23

Annex C (normative) Determination of splice strength ............................................................................... 28

C.1 Principle ........................................................................................................................................................... 28

C.2 Test pieces ....................................................................................................................................................... 28

C.3 Procedure ........................................................................................................................................................ 28

Annex D (informative) Guidance on storage of seals .................................................................................... 29

Annex ZA (informative) Relationship of this European Standard with Regulation (EU)

No.305/2011 .................................................................................................................................................. 30

ZA.1 Scope and relevant characteristics ........................................................................................................ 30

ZA.2 System of Assessment and Verification of Constancy of Performance (AVCP) ...................... 31

ZA.3 Assignment of AVCP tasks ......................................................................................................................... 32

Bibliography ................................................................................................................................................................. 33

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European foreword

This document (prEN 681-1:2016) 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 681-1:1996.

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 Construction Products

Regulation (305/2011/EU).

For relationship with EU Construction Products Regulation (305/2011/EU), see informative Annex ZA

which is an integral part of this document.

The EN 681 series, Elastomeric seals - Material requirements for pipe joint seals used in water and

drainage applications consists of four parts:
Part 1: Vulcanized rubber
Part 2: Thermoplastic elastomers
Part 3: Cellular materials of vulcanized rubber
Part 4: Cast polyurethane sealing elements

Products complying with this European Standard may be used for the transport of water for human

consumption if they comply with the relevant national, regional or local regulatory provisions

applicable in the place of use.
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1 Scope

This European Standard specifies requirements of materials used for vulcanized rubber seals in:

— cold water (T ≤ 50 °C);
— cold water (T ≤ 50 °C) and intermittently hot water (T ≤ 95 °C);
— cold water (T ≤ 50 °C) and continuously hot water (T ≤ 110 °C).

The different designations of seals specified are defined according to their type, application and

requirements (see Table 1).

This European Standard defines requirements for seals, partially defining the properties of the

vulcanized rubber material as a performance indicator of the finished seal. Any additional requirements

called for by the particular application are specified in the relevant product standards taking into

account that the performance of pipe joints is a function of the seal material properties, seal geometry,

pipe system material and pipe joint design. This standard should be used where appropriate with

product standards which specify performance requirements for joints.
It is applicable to elastomeric components of composite or non-composite seals.

In case of composite seals for materials of hardness ranges from 55 IRHD to 95 IRHD, the requirements

for elongation at break, compression set and stress relaxation apply only when the material is

participating in the sealing function, or the long term stability of the seal.

Joint seals made with an enclosed void as part of their design are included in the scope of this European

Standard.
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.

EN 10088-1, Stainless steels - Part 1: List of stainless steels

ISO 34-2, Rubber, vulcanized or thermoplastic — Determination of tear strength — Part 2: Small (Delft)

test pieces

ISO 37, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties

ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD

and 100 IRHD)

ISO 188, Rubber, vulcanized or thermoplastic — Accelerated ageing and heat resistance tests

ISO 815-1, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 1: At ambient

or elevated temperatures

ISO 815-2, Rubber, vulcanized or thermoplastic — Determination of compression set — Part 2: At low

temperatures

ISO 1431-1, Rubber, vulcanized or thermoplastic — Resistance to ozone cracking — Part 1: Static and

dynamic strain testing

ISO 1817, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids

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ISO 3302-1, Rubber — Tolerances for products — Part 1: Dimensional tolerances

ISO 3384-1, Rubber, vulcanized or thermoplastic — Determination of stress relaxation in compression —

Part 1: Testing at constant temperature

ISO 3387, Rubber — Determination of crystallization effects by hardness measurements

ISO 3601-1, Fluid power systems — O-rings — Part 1: Inside diameters, cross-sections, tolerances and

designation codes
ISO 3601-3, Fluid power systems — O-rings — Part 3: Quality acceptance criteria

ISO 9691, Rubber — Recommendations for the workmanship of pipe joint rings — Description and

classification of imperfections

ISO 23529, 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.
3.1
drinking water
water intended for human consumption
4 Application

In Table 1a the application groups and in Table 1b the type and application for seal materials are

defined.
Table 1a — Application Group
Group Application Table Type
I Cold water (T ≤ 50 °C) 3 WA
Cold water (T ≤ 50 °C) and
II 3 WC, WG
intermittently hot water (T ≤ 95 °C)
Cold water (T ≤ 50 °C) and 4 WB, WE
III
continuously hot water (T ≤ 110 °C) 5 WD, WF
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Table 1b — Types
Type Application Table
WA Cold drinking water supply (T ≤ 50 °C) 3
WB Cold drinking water supply (T ≤ 50 °C) 4
and continuously hot drinking water supply (T ≤ 110 °C)
WC Water application, drainage, sewerage and rainwater systems 3
pipes (continuously T ≤ 50 °C and intermittently T ≤ 95 °C)
WD Cold non drinking water supply (T ≤ 50 °C) 4
and continuously hot non drinking water supply (T ≤ 110 °C)
WE Cold drinking water supply (T ≤ 50 °C) 5
and continuously hot drinking water supply (T ≤ 110 °C)
seals manufactured from isoprene-isobutylene copolymer
WF Cold non drinking water supply (T ≤ 50 °C) 5
and continuously hot non drinking water supply (T ≤ 110 °C)
seals manufactured from isoprene-isobutylene copolymer
WG Water application, drainage, sewerage and rainwater systems 3
pipes (continuously T ≤ 50 °C and intermittently T ≤ 95 °C), where
oilresistance is required according to Table 3.
For specific oil resistance applications, consult the manufacturer.

If additional requirements for low temperature resistance are needful, then each type WA, WC and WG

will be amended by an abbreviation “L”.

EXAMPLE WAL means cold drinking water supply (≤50 °C) with additional low temperature resistance.

A nominal hardness shall be specified within the ranges in Table 2.
Table 2 — Hardness categories
Hardness category 40 50 60 70 80 90
Range of hardness IRHD 36 to 45 46 to 55 56 to 65 66 to 75 76 to 85 86 to 95
5 Requirements
5.1 Materials
5.1.1 General

The materials shall be free of any substances which may have a deleterious effect on the fluid being

conveyed, or on the function of the seal, or on the pipe or fitting.
5.1.2 Effect on water quality

For cold and hot drinking water supply, the materials shall not impair the quality of the water under the

conditions of use. The materials shall comply with the national requirements in the country of use.

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5.1.3 Material requirements
Table 3 describes the material requirements for type WA(L),WC(L), WG(L).
The requirements in Table 3 for:
— elongation at break;
— compression set;
— stress relaxation;

are partly different to the requirements in Table 4 and 5. Products according to Table 3 have higher

requirements due to their assembly process.
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Table 3 — Physical property requirements for materials used in types WA(L), WC(L) and WG(L)

Types WA (L), WC (L), WG (L) Requirements for hardness categories
Property Unit Test Clause 40 50 60 70 80 90
method
Permissible tolerance IRHD ISO 48 6.3 ±5 ±5 ±5 ±5 ±5 ±5
on nominal hardness
Tensile strength, min. MPa ISO 37 6.4 9 9 9 9 9 9
Elongation at break, % ISO 37 6.4 400 375 300 200 125 100
min.
Compression set
72 h/23 °C, max. % ISO 815-1 6.5.1 12 12 12 15 15 15
24 h/70 °C, max. % ISO 815-1 6.5.1 20 20 20 20 20 20
72 h/- 10 °C, max. % ISO 815-2 6.5.2 40 40 50 50 60 60
Ageing, 168 h/70 °C
ISO 188 6.6
Hardness change IRHD ISO 48 6.3 +8/-5 +8/-5 +8/-5 +8/-5 +8/-5 +8/-5
Tensile change, max.
% ISO 37 6.4 −20 −20 −20 −20 −20 −20
Elongation at break
change % ISO 37 6.4 +10/-30 +10/-30 +10/-30 +10/-30 +10/-40 +10/-40
Stress relaxation % ISO 3384-1 6.7
168 h/23 °C, max. % 13 14 15 16 17 18
2400 h/23 °C, max. 19 20 22 23 25 26
Volume change in % ISO 1817 6.8
water
168 h/70 °C, max. +8/-1 +8/-1 +8/-1 +8/-1 +8/-1 +8/-1
a — ISO 1431-1 6.9 No cracking when viewed without magnification
Ozone resistance
Additional requirement for Type WG (L)only
Volume change in oil, % ISO 1817 6.13
72 h/70 °C, max %
Oil IRM 901 ±10 ±10 ±10 ±10 ±10 ±10
Oil IRM 903 + 50/- 5 + 50/- 5 + 50/- 5 + 50/- 5 + 50/- 5 + 50/- 5
Additional requirements for Type WAL, WCL and WGL
Compression set % ISO 815-2 6.5.2
72 h/- 25 °C, max. 60 60 60 70 70 70
Hardness change IRHD ISO 3387 6.14
168 h/- 25 °C, max + 18 + 18 + 18 — — —
This requirement is not applicable for unblended EPM and unblended EPDM
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Table 4 describes the requirements for type WB and WD.
Table 4 — Physical property requirements for materials used in types WB and WD
Types WB, WD Requirements for hardness categories
Property Unit Test method Clause 50 60 70 80 90
Permissible tolerance on IRHD ISO 48 6.3 ±5 ±5 ±5 ±5 ±5
nominal hardness
Tensile strength, min. MPa ISO 37 6.4 9 9 9 9 9
Elongation at break, min. % ISO 37 6.4 250 200 150 100 100
Compression set
72 h/23 °C, max. % ISO 815-1 6.5.1 15 15 15 15 15
24 h/125 °C, max. % ISO 815-1 6.5.1 20 20 20 20 20
72 h/- 10 °C, max. % ISO 815-2 6.5.2 40 50 50 60 60
Ageing, 168 h/125 °C ISO 188 6.6
Hardness change IRHD ISO 48 6.3 +8/-5 +8/-5 +8/-5 +8/-5 +8/-5
Tensile change, max. % ISO 37 6.4 −20 −20 −20 −20 −20
Elongation at break
change % ISO 37 6.3 +10/-30 +10/-30 +10/-30 +10/-40 +10/-40
Stress relaxation ISO 3384-1 6.7
168 h/23 °C, max. % 15 15 15 18 18
2400 h/23 °C, max. % 20 22 23 25 26
168 h/125 °C % 30 30 30 30 30
Volume change in water % ISO 1817 6.8
168 h/95 °C, max. +8/-1 +8/-1 +8/-1 +8/-1 +8/-1
a — ISO 1431-1 6.9 No cracking when viewed without magnification
Ozone resistance
Tear strength, min. N ISO 34-2 6.10 20 20 20 20 20
Compression set in water Annex B 6.11
3000 h/110 °C, max. % 30 30 30 30 30
10000 h/110 °C, max. % 40 40 40 40 40
This requirement is not applicable for unblended EPM and unblended EPDM
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Table 5 describes the requirements for type WE and WF.
Table 5 — Physical property requirements for materials used in types WE and WF
Types WE, WF Requirements for hardness categories
Property Unit Test method Clause 50 60 70 80 90
Permissible tolerance on IRHD ISO 48 6.3 ±5 ±5 ±5 ±5 ±5
nominal hardness
Tensile strength, min. MPa ISO 37 6.4 9 9 9 9 9
Elongation at break, min. % ISO 37 6.4 250 200 150 100 100
Compression set
72 h/23 °C, max. % ISO 815-1 6.5.1 15 15 15 15 15
24 h/125 °C, max. % ISO 815-1 6.5.1 20 20 20 20 20
72 h/- 10 °C, max. % ISO 815-2 6.5.2 40 50 50 60 60
Ageing, 168 h/125 °C ISO 188 6.6
Hardness change IRHD ISO 48 6.3 +8/-5 +8/-5 +8/-5 +8/-5 +8/-5
Tensile change, max. % ISO 37 6.4 −20 −20 −20 −20 −20
Elongation at break
change % ISO 37 6.4 +10/-30 +10/-30 +10/-30 +10/-40 +10/-40
Stress relaxation ISO 3384-1 6.7
168 h/23 °C, max. % 15 15 15 18 18
2400 h/23 °C, max. % 30 30 30 30 30
Ozone resistance — ISO 1431-1 6.9 No cracking when viewed without magnification
Compression set in water Annex B 6.11
3000 h/110 °C, max. % 30 30 30 30 30
10000 h/110 °C, max. % 40 40 40 40 40
5.2 General requirements for seal products
5.2.1 Dimensional tolerances

Tolerances shall be specified from the appropriate classes in ISO 3302-1 or for precision O-rings

ISO 3601-1
5.2.2 Imperfections and defects

The seals shall be free of defects or irregularities which affect their function according to ISO 9691 or

for precision O-rings ISO 3601-3. Defects and irregularities shall be agreed upon by customer and

supplier.
6 Test methods
6.1 Test Samples

If satisfactory test pieces cannot be prepared from the finished products in accordance with the

instructions given for the appropriate test method they shall be taken from test slabs or sheets, of

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suitable dimensions, made from the same batch of the elastomer compound used to make the seals and

moulded under conditions which are comparable with those used in production.

For tests in which different sizes of test pieces are permissible, the same size of test piece shall be used

for each batch and for any comparative purposes.

When tested the finished product the test method and the limit values shall be specified between the

manufacturer and the customer.
6.2 Test conditions

Unless otherwise specified, test pieces shall be cut from the finished product by the method specified in

ISO 23529. Test pieces shall be conditioned at standard temperature (23 ± 2) °C and relative humidity

(50 ± 10) % in according to ISO 23529 for at least 3 h before testing.
6.3 Hardness
Tested in accordance with ISO 48, method M for test slabs/sheets.
6.4 Tensile strength and elongation at break

The tensile strength and elongation at break shall be determined by the method specified in ISO 37.

Dumb-bell Type 2 is preferred. The test report shall state the dumb-bell type whenever type 2 is not

used.
6.5 Compression set in air
6.5.1 Compression set at 23 °C, 70 °C and 125 °C

When determined by the method specified in ISO 815-1, use the small type B test piece.

Where the cross section is too small to obtain compression buttons from the product, as an alternative

to moulding buttons, the tension set of the product may be determined, using the method specified in

ISO 2285 with strain 50 % and shall comply with the same test conditions (except strain) and

requirements as for compression set.
6.5.2 Compression set at – 10 °C and – 25 °C

When determined by the method specified in ISO 815-2 using the small type B test piece and the

(30 ± 3) min recovery measurement.
6.6 Accelerated ageing in air
Tested in accordance with ISO 188.
6.7 Stress relaxation in compression

The stress relaxation shall be determined by method A of ISO 3384-1 using the small cylindrical test

piece after applying mechanical and thermal conditioning. Measurements shall be taken after 3 h, 1, 3, 7

days for the 7 day test and after 3 h, 1, 3, 7, 30, 100 days for the 100 days test. The best fit straight line

shall be determined by regression calculation using a logarithmic time scale and the correlation

coefficients derived from these analyses shall not be lower than 0,98 for the 7 day test and 0,95 for the

100 day test.

If the cross section is too small to obtain compression buttons from the product, the stress relaxation in

tension of the product may be determined, using the method specified in Annex A with the same

requirements as for stress relaxation in compression.
The test
...

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