Aerospace series - Pipe coupling 8°30' up to 28 000 kPa Dynamic beam seal - Metric series - Technical specification

This European standard specifies the required characteristics, inspection and test methods, quality
assurance and procurement requirements for metric series 8°30’ dynamic beam seal pipe couplings, for
temperature ranges type II and III according to ISO 6771 and nominal pressure up to 28 000 kPa.

Luft- und Raumfahrt - Rohrverschraubung 8°30' bis 28 000 kPa Dichtlippe - Metrische Reihe - Technische Lieferbedingungen

Série aérospatiale - Système de raccordement 8°30' jusqu'à 28 000 kPa - Joint à lèvre - Série métrique - Spécification technique

La présente norme européenne spécifie les caractéristiques requises, les méthodes de contrôle et d'essai, l'assurance qualité et les exigences d'approvisionnement pour les systèmes de raccordement 8°30’, à joint à lèvre, série métrique, pour les plages de températures de types II et III suivant l‘ISO 6771 et une pression nominale jusqu'à 28 000 kPa.

Aeronavtika - Cevni priključek 8°30' do 28 000 kPa - Dinamično tesnilo snopa - Metrične serije - Tehnična specifikacija

Ta evropski standard določa zahtevane karakteristike, preglede in preskusne metode, zagotavljanje kakovosti in zahteve za nabavo za cevne priključke 8°30' dinamičnega tesnila snopa metričnih serij za
temperaturna območja tipa II in III v skladu s standardom ISO 6771 in nazivni tlak do 28.000 kPa.

General Information

Status
Published
Publication Date
14-May-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-May-2019
Due Date
15-Jul-2019
Completion Date
15-May-2019

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SLOVENSKI STANDARD
SIST EN 3275:2019
01-julij-2019
Nadomešča:
SIST EN 3275:2004
Aeronavtika - Cevni priključek 8°30' do 28 000 kPa - Dinamično tesnilo snopa -
Metrične serije - Tehnična specifikacija

Aerospace series - Pipe coupling 8°30' up to 28 000 kPa Dynamic beam seal - Metric

series - Technical specification

Luft- und Raumfahrt - Rohrverschraubung 8°30' bis 28 000 kPa Dichtlippe - Metrische

Reihe - Technische Lieferbedingungen

Série aérospatiale - Système de raccordement 8°30' jusqu'à 28 000 kPa - Joint à lèvre -

Série métrique - Spécification technique
Ta slovenski standard je istoveten z: EN 3275:2019
ICS:
49.080 Letalski in vesoljski Aerospace fluid systems and
hidravlični sistemi in deli components
SIST EN 3275:2019 en,fr,de

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

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SIST EN 3275:2019
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SIST EN 3275:2019
EN 3275
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2019
EUROPÄISCHE NORM
ICS 49.080 Supersedes EN 3275:2002
English Version
Aerospace series - Pipe coupling 8°30' up to 28 000 kPa
Dynamic beam seal - Metric series - Technical specification

Série aérospatiale - Système de raccordement 8°30' Luft- und Raumfahrt - Rohrverschraubung 8°30' bis 28

jusqu'à 28 000 kPa - Joint à lèvre - Série métrique - 000 kPa Dichtlippe - Metrische Reihe - Technische

Spécification technique Lieferbedingungen
This European Standard was approved by CEN on 5 November 2018.

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, 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 3275:2019 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 3275:2019
EN 3275:2019 (E)
Contents
Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 5

4 Symbols ............................................................................................................................................................... 7

5 Requirements, inspection and test methods ......................................................................................... 7

5.1 Test conditions and preparation of specimens for qualification ................................................... 8

6 Quality assurance ......................................................................................................................................... 23

6.1 Product qualification .................................................................................................................................. 23

6.2 Quality control records .............................................................................................................................. 23

6.3 Acceptance conditions ................................................................................................................................ 23

6.4 Rejection .......................................................................................................................................................... 23

6.5 Purchaser’s (user’s) quality control ...................................................................................................... 24

7 Preparation for delivery ............................................................................................................................ 24

7.1 Cleaning ........................................................................................................................................................... 24

7.2 Preservation and packaging ..................................................................................................................... 24

Annex A (normative) Production batch identification ................................................................................ 28

A.1 Introduction ................................................................................................................................................... 28

A.2 Records ............................................................................................................................................................ 28

A.3 Example of batch identification .............................................................................................................. 29

Bibliography ................................................................................................................................................................. 30

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SIST EN 3275:2019
EN 3275:2019 (E)
European foreword

This document (EN 3275:2019) has been prepared by the Aerospace and Defence Industries

Association of Europe - Standardization (ASD-STAN).

After enquiries and votes carried out in accordance with the rules of this Association, this Standard has

received the approval of the National Associations and the Official Services of the member countries of

ASD, prior to its presentation to CEN.

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 November 2019, and conflicting national standards

shall be withdrawn at the latest by November 2019.

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 3275:2002.

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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
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SIST EN 3275:2019
EN 3275:2019 (E)
1 Scope

This European standard specifies the required characteristics, inspection and test methods, quality

assurance and procurement requirements for metric series 8°30’ dynamic beam seal pipe couplings, for

temperature ranges type II and III according to ISO 6771 and nominal pressure up to 28 000 kPa.

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 2813, Aerospace series — Aluminium alloy AL-P-6061- — T6 — Drawn tube for pressure

applications — 0,6 mm ≤ a ≤ 12,5 mm

EN 3120, Aerospace series — Titanium alloy TI-P64003 — Cold worked and stress relieved — Seamless

tube for pressure systems — 4 mm ≤ D ≤ 51 mm, 690 MPa ≤ R ≤ 1 030 MPa
EN 10204, Metallic products — Types of inspection documents

EN ISO 1302, Geometrical Product Specifications (GPS) — Indication of surface texture in technical

product documentation

ISO 2685, Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in

designated fire zones

ISO 2859-1, Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by

acceptance quality limit (AQL) for lot-by-lot inspection
ISO 5855 (all parts), Aerospace — MJ threads

ISO 6771, Aerospace — Fluid systems and components — Pressure and temperature classifications

ISO 6772, Aerospace — Fluid systems — Impulse testing of hydraulic hose, tubing and fitting assemblies

ISO 7137, Aircraft — Environmental conditions and test procedures for airborne equipment

ISO 7257, Aircraft — Hydraulic tubing joints and fittings — Rotary flexure test

ISO 8625-1, Aerospace — Fluid systems — Vocabulary — Part 1: General terms and definitions related to

pressure

ISO 9538, Aerospace series — Hydraulic tubing joints and fittings — Planar flexure test

TR 2674, Design and construction of pipeline for fluids in liquid or gaseous condition — Rigid lines,

installation

1 Published as ASD-STAN Prestandard at the date of publication of this standard by AeroSpace and Defence

industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).

2 Published as ASD-STAN Technical Report at the date of publication of this standard by AeroSpace and Defence

industries Association of Europe – Standardization (ASD-STAN) (www.asd-stan.org).

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SIST EN 3275:2019
EN 3275:2019 (E)
MIL-H-5606, Hydraulic fluid, Petroleum Base, Aircraft, Missile and Ordnance
MIL-H-8446, Hydraulic fluid, Nonpetroleum Base, Aircraft
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:

 ISO Online browsing platform: available at http://www.iso.org/obp
 IEC Electropedia: available at http://www.electropedia.org/
3.1
pressure

nominal pressure, proof pressure, impulse pressure, burst pressure according to ISO 8625-1

3.2
coupling
3.2.1
coupling assembly

assembled and torque-tightened nut, ferrule and pipe mating with e.g. unions, tees or elbows

Note 1 to entry: See Figure 1.
Key
1 dynamic beam seal
2 ferrule
3 nut
4 union end
Figure 1 — Example of coupling assembly
3.2.2
straight coupling
union connecting pipe to pipe

3 Published by: Department of Defense (DoD), the Pentagon, Washington, D.C. 20301.

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SIST EN 3275:2019
EN 3275:2019 (E)
3.2.3
forged parts
shaped parts
couplings machined out of individual forging blanks

Note 1 to entry: For crosses, tees and elbows machined out of bar or plate stock the term “shaped” may be used.

3.3
surface defects
3.3.1
surface irregularity
nonconformity with general surface appearance, possible defect
3.3.2
crack

clean (crystalline) fracture passing through or across the grain boundaries that possibly follows

inclusions of foreign elements

Note 1 to entry: Cracks are normally caused by overstressing the metal during forging or other forming

operations, or during heat treatment. Where parts are subject to significant reheating, cracks are usually

discoloured by scale.
3.3.3
fold
doubling over of metal, which can occur during the forging operation

Note 1 to entry: Folds can occur at or near the intersection of diameter changes and are especially prevalent

with non-circular necks, shoulders and heads.
3.3.4
lap
fold-like machining defect
3.3.5
seam

(1) usually a surface opening or crack resulting from a defect obtained during casting or forging

(2) extraneous material, stringer in the material, which is not homogeneous with base metal

3.3.6
pit
void or hole in the surface as caused, for example, by corrosion
3.4
quality assurance
3.4.1
production batch

definite quantity of some commodity or service produced at one time under conditions that are

presumed uniform
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SIST EN 3275:2019
EN 3275:2019 (E)
3.4.2
delivery batch

batch consisting of couplings with the same identity block which may come from different production

batches
3.4.3
acceptable quality level
AQL

when a continuing series of lots is considered, a quality level which for the purposes of sampling

inspection is the limit of a satisfactory process average
3.4.4
qualification

testing required to demonstrate successful performance of the coupling assembly in simulated service

(overload, destructive and fatigue tests)
3.4.5
major defect

defect other than critical, that is likely to result in a failure or to reduce materially the usability of the

considered product for its intended purpose
3.4.6
minor defect

defect that is not likely to reduce materially the usability of the considered product for its intended

purpose, or that is a departure from established specification having little bearing on the effective use

or operation of this product
4 Symbols
A Elongation, in percent [%]
D Actual outside diameter of pipe, in millimetres [mm]
D Actual inside diameter of pipe, in millimetres [mm]
DN Nominal outside diameter of pipe
P Working pressure, in megapascals [MPa]
R Tensile strength, in megapascals [MPa]
R 0,2 % proof stress, in megapascals [MPa]
p0,2
σ Axial stress due to pressure, in megapascals [MPa]
5 Requirements, inspection and test methods
See Table 1 and Table 2.
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SIST EN 3275:2019
EN 3275:2019 (E)
5.1 Test conditions and preparation of specimens for qualification
Tests fluids

Unless otherwise specified, tests shall be carried out using e.g. a petroleum base hydraulic fluid to

MIL-H-5606 for coupling assemblies of type II temperature range and a silicate ester base hydraulic

fluid to MIL-H-8446 for those of type III temperature range. Water may be used, whenever practical, for

proof, burst, stress corrosion and re-use capability testing. For other than hydraulic system

applications, it is preferable to use system fluid for leakage (gaseous pressure) and proof testing. When

specified in the test method, the test fluid is used as a lubricant.
Specimen preparation

Shaped parts shall be machined with the grain flow of the bar or plate in the direction of the fluid.

Specimens shall be assembled as illustrated in Table 2. Installations on the pipe end shall be in

accordance with TR 2674. Prior to testing, all couplings shall be assembled using the maximum

specified torque. Except, when specified in Table 2, the coupling shall be assembled using the minimum

installation torque for at least half of the specimens, and maximum torques for the remainder.

Pipe assembly

The method of joining the pipe to the coupling end (brazing, welding, mechanical attachment, etc.) shall

not be detrimental to the properties, strength or geometry of the pipe and the coupling end. The joint

shall be in accordance with the design instructions and shall be inspected by direct measurement, X-ray

or other non-destructive methods.
Table 1 — Requirements, inspection and test methods
a a
Clause Characteristic Requirement Inspection and test method
Q A
Materials Conformity with the Chemical analysis or certificate of X X
5.2
product standards compliance to EN 10204 issued by the
100 % 100 %
semi-finished product manufacturer.
Dimensions Conformity with the Suitable measuring instruments X X
5.3
product standards
100 % 50 %
Fluid passages Conformity with the A ball with a diameter 0,5 mm less than X X
product standards the minimum diameter specified for the
100 % 20 %
passage shall pass through the coupling.
Product Marking according to Visual examination X X
5.4
product standards and
identification 100 % 100 %
definition documents
including batch identifi-
cation of Annex A. It shall be
legible and shall not
adversely affect the material
or the functioning of the
products.
Surface Conformity with the Suitable measuring instruments or X X
5.5
roughness product standards visual-tactile samples
100 % 100 %
Interpreted in accordance
with EN ISO 1302
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A
Surface Conformity with the Visual examination X X
5.6
treatment product standards
The thread shall be tested using a gauge 100 % 100 %
with a tolerance class of 4h6h.

Surface defects Parts shall be free from Visual inspection using suitable methods X X

5.7
surface defects indicated in
100 % 100 %
3.3 liable to have an adverse
Visual examination X X
affect on their
characteristics and
100 % 100 %
endurance.
Threads Threads may be cut, rolled Thread flanks in rolled threads shall be X X
or ground, except titanium examined by micro-examination.
10 % 5 %
alloys which shall be cut or Specimens shall be taken from the
rolled. The external threads finished part by sectioning on a
of couplings should be longitudinal plane across the threaded
rolled and, if machined, area. The specimens shall be polished
shall have an arithmetical and etched to reveal the surface defects.
mean deviation, Ra, of the
profile of 3,2 μm or
smoother in accordance
with EN ISO 1302.
The grain flow in rolled
threads shall be continuous
and follow the general
thread contour with the
maximum density at the
thread root.
Laps, cracks, surface
irregularities and seams
(see 3.3) are not acceptable
on any part of the pressure
thread flank, in the thread
root or on the non-pressure
thread flank. Laps and
seams, depths of which are
within the limits of table,
are acceptable on the crest
and the non-pressure
thread flank above the pitch
diameter.
DN Depth
05 0,15
06 0,18
08 0,18
10 0,20
12 0,23
14 to 32 0,25
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A

5.8 Proof pressure The coupling assembly shall The coupling assembly shall be con- X

withstand a pressure equal nected to a pressure source with one end
to twice the nominal free to move. Rate of pressure increase
pressure of the fluid system shall be (150 000 ± 37 500) kPa/min.
for 5 min at ambient
temperature without
leakage and shall not show
any evidence of permanent
deformation or other
malfunction when using the
specified torque values.
5.9 Gaseous The coupling assembly shall The coupling assembly shall be solvent X
pressure withstand a gaseous cleaned and air dried prior to testing. It
pressure equal to the shall be assembled and tightened to the
nominal pressure for 5 min, minimum torques specified in Table 3. It
at ambient temperature. shall then be pressurized with nitrogen
There shall be no visible to the nominal pressure. This pressure
formation of bubbles after shall be maintained for 5 min while the
1 min at pressure or other specimens are immersed in water or
malfunction that would suitable oil (see Figure 2).
affect assembly or
disassembly when using the
torque values specified.

5.10 Hydraulic The coupling assembly shall The coupling assembly shall be impulse X

impulse withstand 200 000 impulse tested at the temperatures and in the
resistance pressure cycles without sequence specified in ISO 6772.
leakage.
5.11 Minimum The coupling assembly shall The coupling assembly shall be X

burst pressure withstand a pressure equal connected to a pressure source with one

to four times the nominal end free to move.
pressure of the fluid system
Rate of pressure increase shall be
for 5 min, when tested at
(150 000 ± 37 500) kPa/min.
ambient temperature.
There shall be no leakage or
burst.
Pipe expansion is
permissible. The coupling
assemblies need not meet
any disassembly or
assemblies requirements
after this test.
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A

5.12 Flexure fatigue Coupling assembly welded In accordance with either ISO 7257 or X

resistance to pipes shall achieve a ISO 9538. The bending stress shall be
target minimum flexure determined prior to the application of
fatigue stress of 130 MPa internal pressure.
for 10 cycles.
In order to obtain the true bending
stress, it is always necessary to measure
For other methods of
the strain dynamically at the flexure test
joining the coupling to the
frequency. The tolerance for the specified
pipe the minimum flexure
bending stress shall be from 0 % to 10 %.
fatigue levels for each
DN size shall be as shown in
NOTE If it is desired to express the
Table 4a or Table 4b. stress in terms of combined pressure and
bending stress, the axial pressure stress is
Specimens according to
calculated by the formula:
Figure 3 shall pass this test
without leakage from the
coupling assembly or the
𝜎 =𝑃⋅
2 2
𝐷 −𝐷
pipe/coupling interface. 0 1
Recorded S/N curves shall
show characteristics equal
to or greater than those of
Figure 4.
Thrust wire coupling
assemblies shall achieve the
flexure fatigue stress of
130 MPa for 107 cycles,
measured at the pipe/
coupling joint.

5.13 Stress The coupling assembly shall The coupling assembly shall be installed X

corrosion withstand salt spray in a test apparatus (see Figure 5) which
resistance exposure without any of the imposes a bending stress level equal to
following defects: (85 ± 5) % of R of the pipe material
p0,2
at the beam seal interface.
a) indications of cracking
or pitting of the exposed
Internal pressure equal to the nominal
surfaces when visually
pressure of the hydraulic system shall be
examined at 10 times
applied without removing the bending
magnification;
stress. The coupling assembly shall then
be subjected to the salt spray test in
b) indications of inter- or
accordance with ISO 7137.
transgranular corrosive
attack during
After exposure, the coupling assembly
metallurgical
shall be subjected to the minimum burst
examination of
pressure test. The coupling assembly
longitudinal and
shall then be cleaned and subjected to
transverse sections of
micro-examination by sectioning.
the coupling assembly.
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A
5.14 Re-use The coupling assembly shall The coupling assembly shall be tested X
capability withstand 25 repeated according to Figure 6 with one end
assemblies, without any of torqued to the maximum and the other to
the following defects: the minimum value of the tightening
torque with no additional lubricant
a) leakage at any of the
permitted for the first tightening. Each
proof pressure tests;
coupling assembly shall then be
b) inability to tighten the
disassembled, and the sealing face
coupling by hand;
rotated 60° to 90°; the coupling assembly
c) nut deformation;
shall then be lubricated with the test
fluid on threads only and retorqued to
d) excessive galling or
damage to any surfaces the original value to a minimum of
of the coupling assembly 25 times. After each fifth and the final
which prevents the tightening operation, the coupling shall
be subjected to the gaseous pressure test
specified tightening
torques from being according to 5.9.
applied smoothly;
e) gaseous leakage after
the final tightening
operation.
The torque to damage shall Every sixth tightening, the union on the
also be determined and the test fixture shall be replaced.
values recorded. For
The test fixture shall be designed to
couplings in titanium alloy
ensure that all assembly forces are
it shall not be less than
induced into the dynamic beam seal.
two times the maximum
The torque to damage shall be
torque, according to Table 3
determined as follows:
up to DN 18 or 202 Nm
Using one specimen, the curve
starting from DN 20. For
torque/angular rotation of the nut shall
other materials values to be
be established using a calibrated torque
specified.
wrench and a means of measuring the
Damage is defined as one or
angular rotation of the nut. The nut and
more of the following
ferrule thread and contact faces shall be
defects:
lubricated with the test fluid, but none is
a) distortion or cracking of
allowed on the sealing face or dynamic
the dynamic beam seal;
beam seal. The torque shall be increased
b) plastic deformation of until plastic deformation occurs (see
any part of the nut or Figure 7).
ferrule;
c) leakage.
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A
The specimen shall then be subjected to
the gaseous pressure test according to
5.9.
If no leakage occurs, the specimen shall
be disassembled and the dynamic beam
seal examined for cracks or distortion. If
the dynamic beam seal is not damaged,
the torque to damage shall be
determined in accordance with Figure 7.
If leakage or cracking of the dynamic
beam seal is observed, a second
specimen shall be tested. This specimen
shall be torqued to the maximum value
and subjected to a gaseous pressure test
according to 5.9 and the dynamic beam
seal examined for cracks or distortion.
The coupling assembly shall then be
progressively torqued in increments
equal to 20 % of the difference between
the deformation torque of the first
specimen and the maximum torque of
Table 3 for couplings in titanium alloy.
For other materials values to be
specified.
After each increment the specimen shall
be subjected to the gaseous pressure test
according to 5.9 and the dynamic beam
seal examined for cracks or distortion.
Any leakage, cracking or distortion shall
be noted. The torque value at which no
damage was found shall be considered as
the torque to damage.

5.15 Tensile The coupling assembly shall The coupling assembly shall be mounted X

strength withstand a tensile in a tensile test machine with no internal
load ≥ the burst fluid or pressure. The tensile load shall
(coupling
pressure × the cross be applied at a constant speed at a rate of
assembly with
sectional area of the pipe. (4 ± 2,5) mm/min until rupture of the
welded ferrule
associated pipe.
It shall be demonstrated
only)
that the coupling assembly
is at least as strong as the
associated pipe.
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SIST EN 3275:2019
EN 3275:2019 (E)
a a
Clause Characteristic Requirement Inspection and test method
Q A

5.16 Thermal shock The coupling assembly shall The coupling assembly shall be mounted X

resistance not leak during the test. in a low temperature test chamber and
connected to a pressure source of test
fluid which can be heated to maximum
temperature ±5 °C.
The coupling assembly shall be cooled to
−55 °C ± 2 °C for a minimum of 2 h. At
the end of this period, test fluid at the
maximum temperature shall be
introduced at a minimum pressure of
350 kPa.
Within 15 s of the fluid entering the
coupling assembly the pressure shall be
raised to proof pressure and held for
15 min.
5.17 Resistance to The coupling assembly shall In accordance with ISO 2685. X
fire be fireproof for 15 min
without leakage.
(if required)
Q: Qualification, A: Acceptance
Applicable to parts prior to assembly.

Table 2 — Inspection, testing and specimens for qualification of coupling assemblies

Specimen
Test Clause Specimen Quantity Sizes Remarks
number
each total
coupling assemblies prior to the
Proof pressure 5.8 all
following tests
Gaseous
5.9 6 1 to 6 all
pressure
3 7 to 9
Hydraulic
impulse 5.10 6 all
resistance
3 10 to 12
3 13 to 15
Minimum
b, c
5.11 6 all
burst pressure
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SIST EN 3275:2019
EN 3275:2019 (E)
Specimen
Test Clause Specimen Quantity Sizes Remarks
number
each total
10 19 to 28
Flexure fatigue
5.12 12 all
resistance
2 29 and 30
Stress
corrosion 5.13 3 31 to 33 DN16
resistance
Re-use
5.14 3 34 to 36 all
capability
alternative:
Tensile
5.15 2 37 and 38 all
strength
2 DN10
Thermal shock
5.16 39 to 42
cold fluid/hot specimen
resistance
hot fluid/cold specimen 2 DN16
Resistance to
5.17 2 43 and 44 DN16
fire
NOTE
...

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