SIST EN 13555:2014

SLOVENSKI STANDARD
SIST EN 13555:2014
01-julij-2014
1DGRPHãþD
SIST EN 13555:2005
3ULUREQLFHLQSULUREQLþQLVSRML3UHVNXVQLSRVWRSNL]DGRORþDQMHSDUDPHWURY
WHVQLONLVRSRWUHEQL]DNRQVWUXLUDQMHSULURELþQLKVSRMHYVHVWDYOMHQLKL]RNURJOLK
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Flanges and their joints - Gasket parameters and test procedures relevant to the design
rules for gasketed circular flange connections
Flansche und ihre Verbindungen - Dichtungskennwerte und Prüfverfahren für die
Anwendung der Regeln für die Auslegung von Flanschverbindungen mit runden
Flanschen und Dichtungen
Brides et leurs assemblages - Paramètres de joints et procédures d'essai relatives aux
règles de calcul des assemblages à brides circulaires avec joint
Ta slovenski standard je istoveten z: EN 13555:2014
ICS:
23.040.60 Prirobnice, oglavki in spojni Flanges, couplings and joints
elementi
SIST EN 13555:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 13555:2014

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SIST EN 13555:2014

EUROPEAN STANDARD
EN 13555

NORME EUROPÉENNE

EUROPÄISCHE NORM
April 2014
ICS 23.040.60; 23.040.80 Supersedes EN 13555:2004
English Version
Flanges and their joints - Gasket parameters and test
procedures relevant to the design rules for gasketed circular
flange connections
Brides et leurs assemblages - Paramètres de joints et Flansche und ihre Verbindungen - Dichtungskennwerte und
procédures d'essai relatives aux règles de calcul des Prüfverfahren für die Anwendung der Regeln für die
assemblages à brides circulaires avec joint Auslegung von Flanschverbindungen mit runden Flanschen
und Dichtungen
This European Standard was approved by CEN on 28 February 2014.

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, 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.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13555:2014 E
worldwide for CEN national Members.

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SIST EN 13555:2014
EN 13555:2014 (E)
Contents Page
Foreword .4
Introduction .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Symbols .8
5 List of gasket parameters .9
6 Test equipment .9
6.1 Design .9
6.2 Test platens .9
6.3 Metal Foils . 10
6.4 Surface finish . 10
6.5 Measurement of gasket thickness . 10
6.6 Loading . 10
6.7 Temperature . 10
6.8 Leakage measurement . 11
7 Test gaskets . 11
7.1 Number of gaskets. 11
7.2 Procurement and identification of gaskets . 11
7.3 Pre-conditioning of the gaskets . 11
7.4 Dimensions of test gaskets . 11
7.5 Measurement of test gaskets as received . 12
7.6 Influence of gasket dimensions . 12
8 Test procedures . 13
8.1 General . 13
8.2 Testing Strategy . 13
8.3 Reference gasket thickness . 13
8.4 Compression curve . 13
8.5 Determination of Q . 14
smax
8.6 Determination of the values of E . 17
G
8.7 Determination of P and Δe . 19
QR Gc
8.8 Determination of Q and Q . 19
min(L) smin(L)
8.9 Determination of Q at elevated temperatures . 22
smin(L)
8.10 Determination of axial coefficient of thermal expansion . 22
8.11 Determination of the coefficient of static friction . 23
9 Report details . 23
Annex A (informative) Generalised test rig schematic . 24
Annex B (informative) Test rig schematic for compression and compression creep tests . 25
Annex C (informative) Test rig schematic for ambient temperature leakage measurement . 26
Annex D (informative) Schematic of leakage rig allowing use of interchangeable face plate . 27
Annex E (informative) Transferability of measured leakage rates to service conditions . 28
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SIST EN 13555:2014
EN 13555:2014 (E)
Annex F (informative) The measurement of the sealing parameter Q after long term
smin(L)
service simulating exposure to elevated temperature . 29
Figure F.1 — The measurement of sealing parameters of heat aged gaskets . 29
Annex G (informative) Determination of the sealing characteristics of strip sealing materials
available in coil form . 31
Annex H (informative) Proposed method for the determination of the coefficient of static friction,
µ , of gaskets . 32
G
Bibliography . 34

3

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SIST EN 13555:2014
EN 13555:2014 (E)
Foreword
This document (EN 13555:2014) has been prepared by Technical Committee CEN/TC 74 “Flanges and their
joints”, the secretariat of which is held by DIN.
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 October 2014, and conflicting national standards shall be withdrawn at
the latest by October 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13555:2004.
In comparison to EN 13555:2004 the following changes have been made:
a) in Clause 3 the list of definitions has been revised;
b) in Clause 4 the list of symbols has been revised;
c) a new sub-clause 6.3 with testing requirements for metal foils has been added;
d) sub-clause 6.4 on surface finish has been revised;
e) sub-clauses 7.2 and 7.3 on test gaskets have been revised;
f) Clause 8 including Figure 1a) to Figure 6 on testing procedures has been completely revised;
g) in Clause 9 the report details have been revised;
h) Annex F on relationship of gasket parameters in EN 13555 with those from PVRC method has been
revised;
i) a new informative Annex G on determination of the sealing characteristics of strip sealing materials
available in coil form has been added;
j) a new informative Annex H on the proposed method for the determination of the coefficient of static
friction of gaskets has been added.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, 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 the United Kingdom.
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SIST EN 13555:2014
EN 13555:2014 (E)
Introduction
This document provides the test procedures to allow the generation of the gasket parameters to enable the
design equations established in EN 1591-1 to be employed. The same test procedures may be used for “Type
Testing” of gaskets and gasket materials. These procedures are not for routine quality control purposes.
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SIST EN 13555:2014
EN 13555:2014 (E)
1 Scope
This European Standard specifies the gasket parameters required by EN 1591-1 and provides the test
procedures for establishing the values of these parameters.
Gaskets which are wholly based upon elastomers, or based upon elastomers with only the inclusion of
particulate fillers or particulate reinforcement, as opposed to gaskets combining elastomers, fillers and fibrous
reinforcement, are beyond the scope of this document.
NOTE The testing procedures given might be applicable to gaskets of other shapes and dimensions.
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 1092 (all parts), Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated
EN 1514-1, Flanges and their joints - Dimensions of gaskets for PN-designated flanges - Part 1: Non-metallic
flat gaskets with or without inserts
EN 1514-2, Flanges and their joints - Gaskets for PN-designated flanges - Part 2: Spiral wound gaskets for
use with steel flanges
EN 1514-3, Flanges and their joints - Dimensions of gaskets for PN-designated flanges - Part 3: Non-metallic
PTFE envelope gaskets
EN 1514-4, Flanges and their joints - Dimensions of gaskets for PN-designated flanges - Part 4: Corrugated,
flat or grooved metallic and filled metallic gaskets for use with steel flanges
EN 1514-6, Flanges and their joints - Dimensions of gaskets for PN-designated flanges - Part 6: Covered
serrated metal gaskets for use with steel flanges
EN 1514-7, Flanges and their joints - Gaskets for PN-designated flanges - Part 7: Covered metal jacketed
gaskets for use with steel flanges
EN 1591-1, Flanges and their joints - Design rules for gasketed circular flange connections - Part 1:
Calculation
EN 1759 (all parts), Flanges and their joint - Circular flanges for pipes, valves, fittings and accessories, Class
designated
EN 12560-1, Flanges and their joints - Gaskets for Class-designated flanges - Part 1: Non-metallic flat gaskets
with or without inserts
EN 12560-2, Flanges and their joints - Dimensions of gaskets for Class-designated flanges - Part 2: Spiral
wound gaskets for use with steel flanges
EN 12560-3, Flanges and their joints - Gaskets for Class-designated flanges - Part 3: Non-metallic PTFE
envelope gaskets
EN 12560-4, Flanges and their joints - Gaskets for Class-designated flanges - Part 4: Corrugated, flat or
grooved metallic and filled metallic gaskets for use with steel flanges
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SIST EN 13555:2014
EN 13555:2014 (E)
EN 12560-5, Flanges and their joints - Gaskets for Class-designated flanges - Part 5: Metallic ring joint
gaskets for use with steel flanges
EN 12560-6, Flanges and their joints - Gaskets for Class-designated flanges - Part 6: Covered serrated metal
gaskets for use with steel flanges
EN 12560-7, Flanges and their joints - Gaskets for Class-designated flanges - Part 7: Covered metal jacketed
gaskets for use with steel flanges
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
Q
smax
the maximum surface pressure that may be imposed on the gasket at the indicated temperatures without
collapse or “crash”, compressive failure, unacceptable intrusion into the bore or damage of the stressed area
of the gasket such that failure was imminent
3.2
Q
min(L)
the minimum gasket surface pressure on assembly required at ambient temperature in order to seat the
gasket into the flange facing roughness and close the internal leakage channels so that the tightness class is
to the required level L for the internal test pressure
3.3
Q
smin(L)
the minimum gasket surface pressure required under the service pressure conditions, (i.e.) after off loading
and at the service temperature, so that the required tightness class L is maintained for the internal test
pressure
3.4
L
N
the tightness classes are defined in Table 1 in terms of specific leak rates. Additional, better, tightness classes
can be introduced as required by continuing the series
Table 1 — Tightness classes
Tightness class L L L L
N 1,0 0,1 0,01
- 1 - 1
Specific leak rate [mg s m ] ≤ 1,0 ≤ 0,1 ≤ 0,01
3.5
P
QR
this factor to allows for the effect on the imposed load of the relaxation of the gasket between the completion
of bolt up and long term experience of the service temperature
3.6
E
G
this is the unloading modulus of elasticity and it is determined from the thickness recovery of the gasket
between the initial compression surface pressure and unloading to a third of this initial surface pressure
3.7
α
G
this is the coefficient of thermal expansion of the gasket under the service conditions of temperature and
gasket surface pressure in the axial direction
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SIST EN 13555:2014
EN 13555:2014 (E)
3.8
Δe
Gc
this is the additional change in thickness of the gasket or sealing element due to creep between the
completion of the loading and the end of the test period
3.9
µ
G
this is the static friction factor between the gasket and the flange facing during service conditions and under
external loading
4 Symbols
For the purposes of this document, the following notations apply.
Where units are applicable, they are shown in brackets. Where units are not applicable, no indication is given.
- 1
α
the axial coefficient of thermal expansion of gasket [K ]
G
µ
the static friction factor between the gasket and the flange facing —
G
e
gasket or sealing element thickness [mm]
G
Δe
change in gasket or sealing element thickness due to creep [mm]
Gc
2
A
area of gasket subjected to surface pressure [mm ]
G
d internal diameter of gasket [mm]
d
internal diameter of area of gasket subjected to surface pressure [mm]
s
D external diameter of gasket [mm]
D
external diameter of area of gasket subjected to surface pressure [mm]
s
E
unloading modulus of elasticity of the gasket [MPa]
G
- 1 - 1
L
tightness class — subscript N indicates the maximum specific leakage rate for [mg s m ]
N
that tightness class
P creep relaxation factor, the ratio of the residual and initial surface pressures —
QR
Q surface pressure [MPa]
Q
gasket surface pressure at assembly prior to unloading [MPa]
A
Q
the minimum level of surface pressure required for leakage rate class L on [MPa]
min(L)
assembly
Q the minimum level of surface pressure required for leakage rate class L after [MPa]
smin(L)
off-loading
Q
the maximum surface pressure that can be safely imposed upon the gasket at [MPa]
smax
the service temperature without damage
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SIST EN 13555:2014
EN 13555:2014 (E)
Concordance with EN 1591-1:
Q , the gasket surface pressure at assembly is the gasket stress at the load situation 0 and is defined by Q
A A
in EN 1591-1.
5 List of gasket parameters
The gasket parameters relevant to the calculation procedures for the design of bolted flange connections as
given in EN 1591-1 are shown in Table 2 together with the test procedures applicable for determining the
value of the parameter in each case.
Table 2 — Gasket parameters and test procedures
Gasket Definition Test procedure(s)
parameter Subclause Subclause
Q 3.1 8.5
smax
Q 3.2 8.8
min(L)
Q 3.3 8.8 and 8.9
smin(L)
L 3.4 8.8 and 8.9
N
P 3.5 8.7
QR
E 3.6 8.6
G
α 3.7 8.10
G
Δe 3.8 8.7
Gc
µ 3.9 8.11
G
6 Test equipment
6.1 Design
Schematics of test rigs for compression, creep relaxation, and tightness measurement are shown in
informative Annexes A to D. Annex A is a generalised schematic with the other figures providing further detail
for specific aspects of the tests.
6.2 Test platens
The test platens, and heater assembly where appropriate, shall be sufficiently rigid so that any load imposed
on the gasket can be withstood and so that there is no platen deformation which results in gasket surface
pressure variation. This rigidity aspect can also be important when gasket elastic recovery is being
investigated.
The dimensions of the test platen raised faces shall be as given in EN 1092-1 for a DN 40 / PN 40 gasket and
EN 1759-1 for an NPS 4 CLASS 300 gasket.
For testing in tongue and groove geometries the test platens should be in accordance with EN 1092-1, Form
C and Form D or EN 1759-1.
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SIST EN 13555:2014
EN 13555:2014 (E)
6.3 Metal Foils
Experience has shown that during hot compression tests, that is the P , Q and elevated temperature
QR smax
tightness tests, some gasket materials are likely to adhere badly enough to the test platens during the test to
cause difficulty in the removal of the gasket after the completion of the test and damage the platen surface
finish.
To avoid such damage, stainless steel foils or shims of thickness of 0,05 mm placed between the test gasket
and the platens during P and Q tests may be used.
QR smax
Where foils or shims are used the fact of their use shall be included in the test report.
Foils or shims shall not be re-used or used in tightness tests at any temperature nor in the Coefficient of Static
Friction determination defined in 8.11 and provisionally detailed in Annex H.
NOTE A formal investigation into the effect of the use of foils during P and Q testing is planned to be carried out
QR smax
and, as a result, the next revision of this document might not continue to allow the use of foils or shims.
6.4 Surface finish
The platen surface finish shall be within the range specified by the relevant flange standards in the EN 1092
and EN 1759 series. For sheet materials where the standards are EN 1092-1 and EN 1759-1 the finish should
be as specified below.
The surface finish of the test platens shall conform to the following:
3,2 µm < R < 6,3 µm
a
Exceptions to this range are acceptable where the gasket is intended for use with a surface finish outside of
this range. In this case the surface finish used shall be recorded.
Before each test, the freedom from debris from the previous test and from scratch and impact damage to the
surface finish of the platens shall be checked visually.
6.5 Measurement of gasket thickness
For those procedures where the gasket thickness has to be monitored during the test there shall be either
three displacement transducers at 120° spacing around the circumference of the platens or one displacement
transducer placed on the central line.
However, for a leak test, the use of an axial transducer is not recommended as it introduces a sealing
complication to the rig design.
6.6 Loading
Any loading means may be used that allows the gasket to be loaded and unloaded at a required and
consistent rate. The rate of loading and unloading to be used is fixed as:
0,5 MPa/s for all types of gasket except for PTFE based gaskets when 0,1 MPa/s shall be used.
The loading shall be recorded as a function of time.
6.7 Temperature
The rate of increase of temperature in all elevated temperature tests shall be 2 K / min.
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SIST EN 13555:2014
EN 13555:2014 (E)
6.8 Leakage measurement
EN 1779 gives the limits that can be achieved by various method of leakage measurement. The information
given in that document shall be taken into account when selecting a measurement system.
For modern, high performance, sealing materials and gasket styles, the most appropriate method of
measurement is very likely to be mass spectrometry.
7 Test gaskets
7.1 Number of gaskets
At least two gaskets for each type of test shall be tested.
NOTE More rigorous guidance on the number of repeat tests required for each test type will be available for the next
revision of this document.
7.2 Procurement and identification of gaskets
The gaskets to be tested shall be selected at random from production gaskets or shall be cut from sheet
representative of normal production. Prior to selection for test the gaskets or sheet shall have been stored in
accordance with the recommendations of the manufacturer and the time since manufacture should be within
any time limit set by the manufacturer.
Some basic checks shall be made in order to ensure that the gaskets or sheet are acceptable by the normal
quality assurance criteria before the tests to this document are carried out. The results of these checks shall
be recorded.
In all cases, full traceability to production shall be maintained.
7.3 Pre-conditioning of the gaskets
For every gasket type where the sealing element is not solid metal the gasket shall be conditioned as
indicated below before any of the tests of this document are carried out.
The test gasket shall be held for at least 48 hours in air with a relative humidity of (50 ± 6) % at ambient
temperature.
The required relative humidity can for example be generated and maintained by the use of a saturated
solution of magnesium nitrate hexahydrate, Mg (NO ) 6H O. The test gaskets that are to be held at the
3 2 2
required relative humidity should be stored above a saturated solution of the salt, containing an excess of the
solid salt, in a glass container fitted with a ground glass lid and held in an area at ambient temperature.
The test gaskets shall be removed from the conditioning atmosphere no more than 30 min before the test is
carried out.
7.4 Dimensions of test gaskets
The test gasket dimensions shall be either of those specified in Table 3.
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SIST EN 13555:2014
EN 13555:2014 (E)
Table 3 — Test gasket dimensions for Raised Face Flanges
Raised face
Flange description dimensions according Gasket dimensions according to
to
DN 40/PN 40 EN 1092–1 EN 1514–1 to 7 (according to the type of gasket)
NPS 4 CLASS 300 EN 1759–1 EN 12560–1 to 7 (according to the type of gasket)
For convenience for sheet materials the gasket dimensions are given below:
EN 1514–1: ID 49,0 mm OD 92,0 mm
EN 12560–1: ID 115,0 mm OD 148,0 mm
Where the intended service is in tongue and groove flanges, the test gasket size is specified in EN 1092-1 or
in EN 1759-1, and the test shall be carried out with test platens which have a tongue and groove
configuration.
Tolerance of the platens for tongue and groove configurations shall be as given below:
— Negative tolerance for tongue width,
— Positive tolerance for groove width.
If this mode of testing is used it shall be clearly stated in the report.
7.5 Measurement of test gaskets as received
The internal and external diameter of the gasket or sealing face shall be measured with an appropriate device
such as micrometer, caliper or circometer (π tape) at ambient temperature.
Except where a circometer is used, the measurement shall be taken at not less than four positions around the
gasket and the mean diameter shall be reported.
The mean values shall conform to the theoretical values within the tolerances given in the appropriate
document or the supplier's information.
The as received thickness of the gasket or sealing element shall be measured by a micrometer or other
suitable device with contact faces wide enough to provide a measurement without penetration. The value of
the reference gasket thickness is obtained by measuring the gasket thickness under a 1 MPa surface
pressure at ambient temperature and after a one minute stabilisation period. The measurements of thickness
shall be taken at not less than four positions around the gasket or ring and the mean reported. The measured
thickness shall be within the tolerances given in the appropriate document or the supplier's information if no
document exists.
Where the gasket has centering or locating rings associated with the sealing element then the thickness of the
rings shall also be measured and reported.
7.6 Influence of gasket dimensions
For gaskets the test results obtained are influenced by their thickness. For sheet materials the thickness of the
gasket as a function of the surface pressure shall be recorded. This information is generated by the ambient
temperature compression test, see 8.3.
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SIST EN 13555:2014
EN 13555:2014 (E)
8 Test procedures
8.1 General
For all the test procedures detailed in this European Standard the ambient laboratory temperature during the
testing shall be (23 ± 5) °C and the temperature of the
...