EN ISO 14903:2017

SLOVENSKI STANDARD
01-oktober-2017
1DGRPHãþD
SIST EN 16084:2011
+ODGLOQLVLVWHPLLQWRSORWQHþUSDONH2FHQDWHVQRVWLVHVWDYQLKGHORYLQVSRMHY,62

Refrigerating systems and heat pumps - Qualification of tightness of components and
joints (ISO 14903:2017)
Kälteanlagen und Wärmepumpen - Qualifizierung der Dichtheit der Bauteile und
Verbindungen (ISO 14903:2017)
Systèmes de réfrigération et pompes à chaleur - Qualification de l'étanchéité des
composants et des joints (ISO 14903:2017)
Ta slovenski standard je istoveten z: EN ISO 14903:2017
ICS:
27.080 7RSORWQHþUSDONH Heat pumps
27.200 Hladilna tehnologija Refrigerating technology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 14903
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2017
EUROPÄISCHE NORM
ICS 27.080; 27.200 Supersedes EN 16084:2011
English Version
Refrigerating systems and heat pumps - Qualification of
tightness of components and joints (ISO 14903:2017)
Systèmes de réfrigération et pompes à chaleur - Kälteanlagen und Wärmepumpen - Qualifizierung der
Qualification de l'étanchéité des composants et des Dichtheit der Bauteile und Verbindungen (ISO
joints (ISO 14903:2017) 14903:2017)
This European Standard was approved by CEN on 10 June 2017.

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: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14903:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 14903:2017) has been prepared by Technical Committee ISO/TC 86
“Refrigeration and air-conditioning” in collaboration with Technical Committee CEN/TC 182
“Refrigerating systems, safety and environmental requirements” 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 February 2018 and conflicting national standards shall
be withdrawn at the latest by February 2018.
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 16084:2011.
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.
Endorsement notice
The text of ISO 14903:2017 has been approved by CEN as EN ISO 14903:2017 without any modification.
INTERNATIONAL ISO
STANDARD 14903
Second edition
2017-07
Refrigerating systems and heat
pumps — Qualification of tightness of
components and joints
Systèmes de réfrigération et pompes à chaleur — Qualification de
l’étanchéité des composants et des joints
Reference number
ISO 14903:2017(E)
©
ISO 2017
ISO 14903:2017(E)
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

ISO 14903:2017(E)
Contents  Page
Foreword .iv
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 2
4  Symbols . 3
5 Test requirements . 3
6  Requirements for hermetically sealed systems . 8
7  Test procedures . 8
7.1 General . 8
7.2 Sampling . 8
7.3 Test temperature . 8
7.4 Tightness test . 8
7.4.1 General. 8
7.4.2 Tightness level control . . 9
7.5 Requirements for joints .11
7.5.1 Test samples.11
7.5.2 Torque .11
7.5.3 Reusable joint .12
7.5.4 Requirements for hermetically sealed joints .12
7.6 Pressure-temperature vibration tests (PTV) .12
7.6.1 General.12
7.6.2 Samples .12
7.6.3 Test method .12
7.6.4 Method 1: Combined pressure-temperature cycle test with integrated
vibration test .13
7.6.5 Method 2: Combined pressure-temperature cycle test with a separate
vibration test .15
7.7 Operation simulation .20
7.8 Freezing test .20
7.9 Additional pressure test for hermetically-sealed joints .21
7.10 Vacuum test .21
7.11 Compatibility screening test .22
7.11.1 General.22
7.11.2 Test fluids .22
7.11.3 Test specimens.22
7.11.4 Test setup parameters .22
7.11.5 Test procedure .23
7.11.6 Pass/fail criteria for sealing elements .23
7.12 Fatigue test for hermetically sealed joints .24
8  Test report .25
9  Information to the user .25
Annex A (informative) Equivalent tightness control levels .26
Annex B (normative) Test arrangements .32
Bibliography .34
ISO 14903:2017(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by the European Committee for Standardization (CEN) Technical
Committee CEN/TC 182, Refrigerating systems, safety and environmental requirements, in collaboration
with ISO Technical Committee TC 86, Refrigeration and air-conditioning, Subcommittee SC 1, Safety and
environmental requirements for refrigerating systems, in accordance with the Agreement on technical
cooperation between ISO and CEN (Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 14903:2012), which has been technically
revised.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 14903:2017(E)
Refrigerating systems and heat pumps — Qualification of
tightness of components and joints
1  Scope
This document provides the qualification procedure for type approval of the tightness of hermetically
sealed and closed components, joints and parts used in refrigerating systems and heat pumps as
described in relevant parts of ISO 5149. The sealed and closed components, joints and parts concerned
are, in particular, fittings, bursting discs, flanged or fitted assemblies. The tightness of flexible piping
made from non-metallic materials is dealt with in ISO 13971. Metal flexible piping are covered by this
document.
The requirements contained in this document are applicable to joints of maximum DN 50 and
components of internal volume of maximum 5 l and maximum weight of 50 kg.
This document is intended to characterize their tightness stresses met during their operations,
following the fitting procedure specified by the manufacturer, and to specify the minimal list of
necessary information to be provided by the supplier of a component to the person in charge of carrying
out this procedure.
It specifies the level of tightness of the component, as a whole, and its assembly as specified by its
manufacturer.
It applies to the hermetically sealed and closed components, joints and parts used in the refrigerating
installations, including those with seals, whatever their material and their design are.
This document specifies additional requirements for mechanical joints that can be recognized as
hermetically sealed joints.
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.
ISO 175, Plastics — Methods of test for the determination of the effects of immersion in liquid chemicals
ISO 1817, Rubber, vulcanized or thermoplastic — Determination of the effect of liquids
ISO 5149-1, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 1:
Definitions, classification and selection criteria
ISO 5149-2, Refrigerating systems and heat pumps — Safety and environmental requirements — Part 2:
Design, construction, testing, marking and documentation
ISO 13971, Refrigeration systems and heat pumps — Flexible pipe elements, vibration isolators, expansion
joints and non-metallic tubes — Requirements and classification
IEC 60068-2-64, Environmental testing — Part 2-64: Tests — Test Fh: Vibration, broadband random and
guidance
EN 1593, Non-destructive testing — Leak testing — Bubble emission techniques
EN 13185:2001, Non-destructive testing — Leak testing — Tracer gas method
ISO 14903:2017(E)
3  Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5149-1 and the following 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
mass flow rate
Q
m
value of the leak mass flow rate at any point of the component
Note 1 to entry: The mass flow rate is expressed in grams (g) per year.
3.2
volume flow rate
Q
value of the leak volume flow rate at any point of the component
Note 1 to entry: The volume flow rate is expressed in Pascal cubic metres per second (Pa∙m /s).
3.3
hermetically-sealed system
system in which all refrigerant containing parts are made tight by welding, brazing or a similar
permanent connection which may include capped valves and capped service ports that allow proper
repair or disposal and which have a tested tightness control level of less than 3 g per year under a
pressure of at least a quarter of the maximum allowable pressure
Note 1 to entry: Sealed systems as defined in ISO 5149-1 are equal to hermetically-sealed systems.
3.4
product family
group of products that have the same function, technology, and material for each functional part and
sealing materials
3.5
closed joint
joint other than hermetically-sealed joints where there is no movement between the sealing surfaces
except for service purposes
EXAMPLE Flanged joints.
3.6
closed component
component other than hermetically-sealed components where there is no movement between the
sealing surfaces except for service purpose
EXAMPLE Stop valves, service ports, pressure-relief valves.
3.7
hermetically-sealed joint
joint that are made tight by welding, brazing or a similar permanent connection
3.8
hermetically-sealed component
component that are made tight by welding, brazing or a similar permanent connection
2 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
3.9
permanent joint
joint which cannot be disconnected except by destructive methods
[SOURCE: Pressure Equipment Directive 2014/68/EU, modified]
3.10
reusable joint
joint made without replacing the sealing material in general procedure
Note 1 to entry: In some cases, the tube is used as sealing material (e.g. flared joint).
3.11
same base material
material belonging to the same group
EXAMPLE Steel group, aluminium and aluminium alloy group or copper group.
Note 1 to entry: Subgroups of these material groups are considered to be same base materials (refer to EN 14276-2).
4  Symbols
Symbol Denomination Unit
Percentage deviation of the minimum and maximum torque from the average of the
D —
K
minimum and maximum torque, (K – K )/(K + K )
max min min max
f Frequency of vibrations Hz
K Average torques of the respective joint standard Nm
ave
Required maximum torques of the respective joint standard, if specified. Otherwise,
K Nm
max
the maximum torque values supplied by the manufacturer.
Required minimum torques of the respective joint standard, if specified. Otherwise,
K Nm
min
the minimum torque values supplied by the manufacturer.
L Length of tube mm
n Number of cycles in temperature and in pressure (method 1) —
n Number of cycles in temperature and in pressure (method 2) —
n Number of cycles in pressure —
n Number of cycles in vibration —
n Total number of cycles in temperature and in pressure —
total
N Number of samples —
P Tightness test pressure bar
P Maximal pressure of cycle bar
max
P Minimal pressure of cycle bar
min
PS Maximal allowable pressure bar
P Nominal set pressure of the device bar
set
Q Volume flow leakage rate mbar l/s
Q Mass flow leakage rate g/a
m
s Vibration displacement (peak to peak value) mm
t Maximal temperature of cycle °C
max
t Minimal temperature of cycle °C
min
5 Test requirements
The required tests to be applied to component bodies and joint used in refrigerating systems and heat
pumps are given in Table 1 and in Table 2.
ISO 14903:2017(E)
Figure 1 illustrates the principle of a component and a joint and their corresponding requirements in
Table 1 or Table 2.
a) According to Table 1
b) According to Table 1
c) According to Table 2
Key
1 joint
2 component body
3 pipe
4 component body joint
5 extension pipe
Figure 1 — Principle: component body-joint
All component types and joints types shall be tested.
When a component may be connected with different types of joints, one of these joints shall be tested
with the component according to Table 1. The other possible types of joints shall be tested independently
according to Table 2.
4 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
Table 1 — Requirements for component bodies
Requirements
PTV- test Additional test for hermeti-
Chemical
(pres- cally sealed
Components (including valves)
Tightness Operation  compati-
sure-temper- Freezing test Vacuum test
test simulation bility with
ature-vibra-
Pressure test Fatigue test
materials
tion)
Subclause 7.4 7.6 7.7 7.8 7.11 7.10 7.9 7.12
Component bodies having only
permanent body joints: brazing and
YES NO NO NO NO NO NO NO
welding
Identical base materials
Components having permanent body
joints: brazing and welding
a
YES YES NO NO NO NO NO NO
Different base materials
Component bodies having other YES
YES
permanent body joints (e.g. glue, if operating
YES YES NO if non-metal- YES YES YES
permanent compression fittings, temperature
lic parts
expansion joints) below 0 °C
YES
if any external
YES
stems, shaft YES
Component bodies with non-perma- if operating
YES YES seals or if non-metal- YES Not applicable Not applicable
nent body joints temperature
removable or lic parts
below 0 °C
replaceable
parts
By exception, compressors that comply with the requirements of EN 12693 or IEC 60335-2-34 only need to be subjected to the following test:
—  joints connecting to other parts of the refrigerating systems;
—  chemical compatibility test for all gaskets (sight glass, etc.).
a
PTV tests are not required if destructive and non-destructive tests of EN 13134 are carried out.
NOTE Other qualifications for this chemical compatibility done according to other standards are equivalent.

ISO 14903:2017(E)
6 © ISO 2017 – All rights reserved
Table 1 (continued)
Requirements
PTV- test Additional test for hermeti-
Chemical
(pres- cally sealed
Components (including valves)
Tightness Operation  compati-
sure-temper- Freezing test Vacuum test
test simulation bility with
ature-vibra-
Pressure test Fatigue test
materials
tion)
Subclause 7.4 7.6 7.7 7.8 7.11 7.10 7.9 7.12
YES
YES
Capped valves and capped service if operating
YES YES YES if non-metal- YES YES YES
ports for hermetically sealed systems temperature
lic parts
below 0 °C
YES
Safety valves YES YES NO NO if non-metal- Not applicable Not applicable Not applicable
lic parts
Flexible piping Test according to ISO 13971
By exception, compressors that comply with the requirements of EN 12693 or IEC 60335-2-34 only need to be subjected to the following test:
—  joints connecting to other parts of the refrigerating systems;
—  chemical compatibility test for all gaskets (sight glass, etc.).
a
PTV tests are not required if destructive and non-destructive tests of EN 13134 are carried out.
NOTE Other qualifications for this chemical compatibility done according to other standards are equivalent.

ISO 14903:2017(E)
Table 2 — Requirements for the joining of components
Requirements
PTV- test Chemical  Additional test for hermeti-
Joints and parts
Tightness (pressure- Operation  compati- cally sealed
Freezing test Vacuum test
test temperature- simulation bility with
Pressure test Fatigue test
vibration) materials
Subclause 7.4 7.6 7.7 7.8 7.11 7.10 7.9 7.12
Permanent piping joints: brazing
and welding
YES NO NO NO NO NO NO NO
Identical base materials
Permanent piping joints: brazing
and welding
YES YES NO NO NO NO NO NO
Different base materials
Other permanent piping joints (e.g.
glue, permanent compression fit- YES YES NO YES YES YES YES YES
tings, expansion joints)
YES, if sealing
Non-permanent piping joints YES YES YES YES YES Not applicable Not applicable
material
Gaskets and sealing NO NO NO NO YES NO Not applicable Not applicable

ISO 14903:2017(E)
6  Requirements for hermetically sealed systems
Hermetically-sealed systems shall be constructed with components which have their tightness control
level qualified as A1 or A2 as per Table 3 or Table 4. These components and joints shall be submitted to
the relevant tests as specified in Tables 1 and 2.
7  Test procedures
7.1 General
The components, joints and part shall pass the tightness test before the other tests are executed. The
different tests are shown in Figure 2.
START
Deine which tests need to
be performed based on
Table 2 and Table 3
Deine the tightness
control level according to
Table 4 and Table 5
For joints, apply 7.5
7.4 Tightness control level
Meets the
7.6 Pressure Temperature tightness control
7.7 Operation simulation 7.4 Tightness control level Pass
Vibration Test (PTV) level in Table 4 and
Table 5
7.8 Freezing test
Fail
7.9 Pressure test for
hemetically sealed
7.10 Vacuum test
7.11 Compatibility test
7.12 Fatigue test for
hermetically sealed joints
Figure 2 — Test procedure
7.2 Sampling
The largest, the smallest and any random samples in between of the product family shall be submitted
to the test as required in Table 1 or Table 2. The samples used for pressure-temperature vibration test
(7.6) and for operation simulation (7.7) shall be the same. For each of the other tests (7.8, 7.9, 7.10, 7.11,
7.12), different samples may be used.
7.3 Test temperature
Test temperature (ambient and gas) shall be 15 °C to 35 °C, unless otherwise specified as the test
conditions.
7.4 Tightness test
7.4.1 General
The tightness of components and joints shall be tested according to the following test pressures.
8 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
For pressure relief devices, P = 0,9 × P (−2) %;
set
For all other components and joints
the test pressure P shall be defined as: P = PS (2) % (PS = Maximum allowable pressure);
Q ≤ requirements for actual tightness control level A1 – A2
(hermetically-sealed components) or B1 – B2 for all other
components.
The maximum required tightness control level are specified for Helium at 10 bar and +20 °C as a
reference.
The actual tightness control levels can be calculated (e.g. other test fluids or pressures) by using the
stated calculation formulas (Annex A).
The maximum tightness control level depends on the size of the tested component or joint. Tightness
control levels are specified in accordance with the joints used in Table 3. These are levels for each
individual joint.
Table 3 — Tightness control level according to joints nominal diameter
Joints DN Tightness control levels
Hermetically sealed joints ≤ 50 A1
Closed joints ≤ 50 B1
For components, the tightness control level depends on the component internal volume and the type of
component as specified in Table 4. These are levels for each individual component.
Table 4 — Tightness control level according to components volume
Component
Tightness con-
Components Volume
trol levels
l
0 up to 1,0 A1
Hermetically sealed components
> 1,0 A2
Closed components 0 up to 2,0 B1
Closed components > 2,0 up to 5,0 B2
The manufacturer can choose more stringent tightness control level if adequate.
Table 5 — Equivalence of test gas flow according to tightness control levels
Helium reference  Equivalent
Tightness control  Equivalent air leak
Component leak iso-butane leak
level at +20 °C, Q
air-ref
type Q m
he-ref R-600a
10 bar Pa∙m /s
Pa∙m /s g/a
−7 −7
A1 ≤ 7,5 × 10 ≤ 8 × 10 ≤ 1,5
Hermetically sealed
−6 −7
A2 ≤ 1 × 10 ≤ 11 × 10 ≤ 2,0
−6 −7
B1 ≤ 1 × 10 ≤ 11 × 10 ≤ 2,0
Closed
−6 −6
B2 ≤ 2 × 10 ≤ 2,1 × 10 ≤ 4,0
NOTE The equivalent iso-butane leak is calculated as gas. At +20 °C and 10 bar, iso-butane is in the liquid phase. See
R-600a in Table A.1.
7.4.2  Tightness level control
7.4.2.1  Test method
ISO 14903:2017(E)
NOTE EN 1779 gives guidance on the criteria for method and technique selection.
The tightness control level of joints and components shown in Table 3 and Table 4 shall be measured by
the vacuum chamber technique which sum all leak.
It is preferable to use tracer gas technique as defined in EN 13185:2001, Clause 10.
The component to be tested is pressurized with the tracer gas and placed in the vacuum chamber in
which the sum of all components leak is measured.
The following procedure shall be carried out to measure the tightness control level:
— connect the vacuum chamber to the detector;
— connect the component to the tracer gas pressure generator (in the vacuum chamber) (see Figure 3);
— close the vacuum box and start the leak detector (and if it is needed add a vacuum pump);
— adjust and calibrate the leak detector according to EN 13185:2001, 9.1.1;
— measure the residual signal in the vacuum box and the component without helium pressure;
— adjust the test pressure in the component;
— measure the leak signal of the component;
NOTE This signal is the total flow of the tracer gas from the component measured by the leak detector.
— calculate the leak level according to the formula given in EN 13185:2001, 9.2.6.
If joints and/or components are tested together, the total level shall fulfil the most stringent tightness
control level of the individual joint or component.
Key
1 tracer gas (P)
2 vacuum
3 mass spectrometric leak detector
4 test object
5 calibrated leak
Figure 3 — Principle of tightness control — Tracer gas
10 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
7.4.2.2  Alternative test methods
Two alternative methods may be applied.
a) Alternative method 1
The control by pressure technique by accumulation, in accordance with EN 13185:2001, 10.4.1,
could be a method to measure the leak rate of the component.
b) Alternative method 2
Bubble test methods shown in Figure 4 can be acceptable for tightness control level B, provided
that the method is capable to measure the actual leakage rate. The bubble test methods shall be
carried out in accordance with EN 1593. The accuracy of the selected method shall be verified and
be in compliance with the requirements for actual tightness control level. If this method is used,
the following requirements shall be applied:
1) the test object shall be subjected to an internal air pressure = PS (maximum allowable
pressure). Reduced pressure is not acceptable;
2) the test object shall be immersed in water;
3) the test object shall be exposed to atmospheric pressure;
4) the test shall be performed at normal ambient temperature;
5) the period of time between bubbles leaving the test object shall be more than 60 s.
3 2
Key
1 water
2 test object
3 air pressure (PS)
Figure 4 — Principle of tightness control — Bubble method
7.5  Requirements for joints
7.5.1 Test samples
All joints tested shall be tested in the final form as the customer receives the part.
All joints shall be submitted to the tests as indicated in Table 2.
7.5.2  Torque
Tube joints shall be tested both at the minimum torque, K , and the maximum torque, K , defined
min max
in Table 6.
ISO 14903:2017(E)
Table 6 — Torque for the test, K and K
min max
K K
min max
IF D > or = 20 % K K
K min max
IF 20 % > D 0,8 × K 1,2 × K
K ave ave
7.5.3  Reusable joint
If the joints to be tested are reusable, the following steps shall be taken before the test:
a) fit the joints to tubes to be connected and tighten the joints to the maximum torque, K , specified
max
in Table 6;
b) loosen the joints and take the tubes completely apart;
c) repeat a) and b) four more times.
7.5.4  Requirements for hermetically sealed joints
The joint shall not be opened without the use of special tools.
NOTE Special tools are other than screw-drivers, parallel wrenches, simple gripping tool, etc.
The joint shall not be reusable without replacing the sealing material in normal use. In case the sealing
material is the tube, including that the tube is deformed during the sealing process, the deformed part
of the tube shall not be reusable for sealing purpose.
7.6  Pressure-temperature vibration tests (PTV)
7.6.1 General
For pressure-temperature vibration tests, method 1 or method 2 as described as follows shall be
applied.
The test on components or joints shall comply with one of the two methods described in 7.6.4 and 7.6.5
for combined cycle testing in order to qualify the tightness level.
7.6.2 Samples
For the combined cycle test, the number of samples is determined based on tightness control level
according to Table 7.
Table 7 — Test parameters
Tightness control level Number of samples
A1, B1 3
A2, B2 2
7.6.3  Test method
7.6.3.1 Equipment
Test equipment shall be composed of:
a) regulated enclosure for environment tests, able to maintain temperatures varying regularly
between t and t ;
min max
12 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
b) pressure device, connected to the joints, capable of producing a pressure that varies between P
min
and P ;
max
c) vibration generator, to make the specified frequency and amplitude;
d) pressure control system capable to control the pressure with an accuracy of ±5 %;
e) temperature control system capable of controlling the temperature inside of the test enclosure
with an accuracy of ±5 °C;
f) temperature sensor capable to monitor the temperature (t , t ) of the component or joint
max min
submitted to the test.
The temperature sensor shall be adhered to the surface of the sample on the item with the biggest
weight concentration of the pressure bearing part in order to ensure that the sample has reached the
defined temperature values. Where the pressure bearing part is made from metallic and non-metallic
materials, the sensor shall be fixed on the non-metallic material.
The sensor can be fixed to the sample by soldering or with adhesives, whichever is more appropriate,
depending on the material of the sample.
Another method, proven to have the same performance as the thermocouple can be applied:
g) cycle counter of temperature and pressure;
h) test equipment to perform tightness test according to 7.4.
7.6.3.2 Test arrangements
The test samples shall be mounted as shown in Annex B in accordance with the number of joints to be
tested and with the dimension of the climatic enclosure in which the tests are carried out.
The tube section shall have a diameter and dimensional tolerances such as specified by the manufacturer
of the joint.
The assembly of the joints on the tube shall be carried out following the fitting instructions of the
manufacturer.
For pressure test, one end of a tube shall be connected to the pressure generator; the other end shall be
tightly closed.
7.6.4  Method 1: Combined pressure-temperature cycle test with integrated vibration test
7.6.4.1 General
The samples (joints fitted on a tube) shall be submitted to a defined number n of cycles of temperature
and pressure, between maximal values (t , P ) and minimal values (t , P ).
max max min min
The test characteristics shall be applied to the components according to Table 8.
A typical temperature-pressure cycle is given in Figure 5.
The pressure shall be held for 2 min.
ISO 14903:2017(E)
Principle PTV-test method 1
Key
1 temperature
2 pressure
3 vibration
Figure 5 — Temperature-pressure cycle test
Table 8 — Test parameters
Parameters Value
n 160
n 5 × n
total
Minimum temperature as specified by the manufacturer or −40 °C if
t
min
this is not specified
Maximum temperature as specified by the manufacturer or +10 °C
t
max
or 140 °C if this is not specified
P Atmospheric pressure
min
For safety valves, P = 0,9 × P
max set
P
max
a
For others components, 1,0 × PS
f 200 Hz
s 0,012 mm
L 200 mm
a
1,0 × PS is proposed because of safety issue for test on big component.
The test fluid shall not be a liquid.
7.6.4.2  Procedure
7.6.4.2.1 Fit the test items on a test-rig in accordance with the instructions of the manufacturer.
14 © ISO 2017 – All rights reserved

ISO 14903:2017(E)
7.6.4.2.2 Fix the test parameters (n, t , t , P , P , f, s) in accordance with Table 8.
max min max min
7.6.4.2.3 Submit the test items to the test pressure according to Table 8.
7.6.4.2.4 Check the tightness of the joints by sniffing gas in order to detect leaks before test.
7.6.4.2.5 Tighten again the joints which leak according to the instructions of the manufacturer.
7.6.4.2.6 Place the test items in the climatic enclosure and submit them to n pressure and temperature
cycles in accordance with Figure 5 and Table 8. Simultaneously submit the component assembly to the
vibration test of frequency, f, and displacement, s.
7.6.4.2.7 Before the n pressure, temperature cycles and vibrations test, submit the joints to the
operation simulation if it is needed according to Table 1 or Table 2, as described in 7.7.
7.6.4.2.8 Repeat the procedure of 7.6.4.2.6 and 7.6.4.2.7 five times in total.
7.6.4.2.9 Expose the joints to the tightness test as specified in 7.4. The pass-fail criteria shall be the
tightness control levels according to the test gas shown in Table 5.
7.6.5  Method 2: Combined pressure-temperature cycle test with a separate vibration test
7.6.5.1 General
In contrast with method 1, the combined pressure-temperature cycle test shall be performed separately
from the vibration test.
7.6.5.2  Requirements for the combined pressure-temperature cycle test
The samples shall be submitted to a defined number n of cycles of temperature and pressure, between
maximal values (t , P ) and minimal values (t , P ), and n cycles of pressure between
max max min min 2
maximum value (P ) and minimum value (P ) with fixed temperature value (t ).
max min max
The test characteristics to be applied to the components are defined in Table 9.
A typical temperature-pressure cycle is given in Figure 6.
NOTE The shape of the curve is theoretical.
ISO 14903:2017(E)
1 1
2 2
Key
1 temperature
2 pressure
3 vibration
Figure 6 — Temperature-pressure cycle test with a separate vibration test
Table 9 — Test parameters
Parameters Value
n 50
n 200
n 2 × 10
Minimum temperature as specified by the manufacturer or −40 °C
t
min
if this is not specified
Maximum temperature as specified by the manufacturer or +10 °C
t
max
or 140 °C if this is not specified
P Atmospheric pressure
min
For safety valves, P = 0,9 × P
max set
P
max
a
For others components 1,0 × PS
a
1,0 × PS is proposed because of safety issue for test on big component. In method 2,
the number of cycles and the level of vibration are extended to compensate for the
reduced pressure.
The test fluid shall not be a liquid.
7.6.5.3  Procedure
7.6.5.3.1 Fit the test items on a test-bed in accordance with the instructions of the manufacturer.
7.6.5.3.2 Fix the test parameters (n , n t , t , P , P ) in accordance with Table 9.
1 2, max min max min
7.6.5.3.3 Submit the test items to the test pressure according to Table 9.
7.6.5.3.4 Check the tightness of the joints by sniffing gas in order to detect leaks before test.
7.6.5.3.5 Tighten again the joints which leak according to the instructions of the manufacturer.
7.6.5.3.6 Execute the operation simulation according to 7.7.
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