SIST EN ISO 19879:2021

SLOVENSKI STANDARD
oSIST prEN ISO 19879:2019
01-maj-2019
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Metallic tube connections for fluid power and general use - Test methods for hydraulic
fluid power connections (ISO/DIS 19879:2019)
Metallische Rohrverschraubungen für Fluidtechnik und allgemeine Anwendung -
Prüfverfahren für hydraulische Rohrverschraubungen in der Fluidtechnik (ISO/DIS
19879:2019)
Raccords de tubes métalliques pour transmissions hydrauliques et pneumatiques et
applications générales - Méthodes d'essai pour raccords pour transmissions
hydrauliques (ISO/DIS 19879:2019)
Ta slovenski standard je istoveten z: prEN ISO 19879
ICS:
23.100.40 Cevna napeljava in sklopke Piping and couplings
oSIST prEN ISO 19879:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 19879:2019

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oSIST prEN ISO 19879:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 19879
ISO/TC 131/SC 4 Secretariat: ANSI
Voting begins on: Voting terminates on:
2019-03-15 2019-06-07
Metallic tube connections for fluid power and general
use — Test methods for hydraulic fluid power connections
Raccords de tubes métalliques pour transmissions hydrauliques et pneumatiques et applications
générales — Méthodes d'essai pour raccords pour transmissions hydrauliques
ICS: 23.040.60; 23.100.40
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 19879:2019(E)
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. ISO 2019

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oSIST prEN ISO 19879:2019
ISO/DIS 19879:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
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Phone: +41 22 749 01 11
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Email: copyright@iso.org
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Published in Switzerland
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oSIST prEN ISO 19879:2019
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Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 1
4.1 Test assemblies . 2
4.2 Test equipment . 5
4.2.1 Test block. 5
4.2.2 Test seals . 5
4.3 Procedure . 6
4.3.1 Thread lubrication . . 6
4.3.2 Torque . 6
4.3.3 Temperature . 6
4.4 Test report . 6
5 Repeated assembly test . 6
5.1 Principle . 6
5.2 Procedure . 6
5.3 Re-use of components . 7
6 Leakage test . 7
6.1 Principle . 7
6.2 Procedure . 7
6.3 Re-use of components . 8
7 Proof test . 8
7.1 Principle . 8
7.2 Procedure . 8
7.3 Re-use of components . 9
8 Burst test. 9
8.1 Principle . 9
8.2 Procedure . 9
8.3 Re-use of components . 9
9 Cyclic endurance test . 9
9.1 Principle . 9
9.2 Procedure . 9
9.3 Re-use of components . 9
10 Vacuum test .10
10.1 Principle .10
10.2 Procedure .10
10.3 Re-use of components .10
11 Overtightening test .10
11.1 Principle .10
11.2 Test equipment .11
11.3 Procedure .11
11.4 Re-use of components .11
12 Vibration test .11
12.1 Principle .11
12.2 Procedure .11
12.3 Re-use of components .13
13 Cyclic endurance (impulse) test with vibration .13
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13.1 Principle .13
13.2 Procedure .14
13.3 Re-use of components .14
14 Identification statement (Reference to this International Standard) .14
Annex A (normative) Test data form .16
Bibliography .19
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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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International
Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies
casting a vote.
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.
ISO 19879 was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 4,
Connectors and similar products and components.
This second edition of ISO 19879 cancels and replaces the first edition (ISO 19879:2005) of which it
constitutes a minor revision, with minor changes to 10.1, 10.2 (Table 7) and 12.2.2. (It also incorporates
the Technical Corrigendum ISO 19879-1:2005/Cor: 2007.)
The main changes since the last revision clarifies the language used to describe the connector end as
well as the proper method for selecting tubes for test assemblies.
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Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure
within an enclosed circuit. It is required that components be designed to meet these requirements
under varying conditions. Testing of components to meet performance requirements provides a basis of
assurance for determining design application and for checking component compliance with the stated
requirements.
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oSIST prEN ISO 19879:2019
DRAFT INTERNATIONAL STANDARD ISO/DIS 19879:2019(E)
Metallic tube connections for fluid power and general
use — Test methods for hydraulic fluid power connections
1 Scope
This International Standard specifies uniform methods for the testing and performance evaluation
of metallic tube connections, stud ends for ports and flange connections for use in hydraulic fluid
power applications. This International Standard does not apply to the testing of hydraulic quick-action
couplings, which is covered by ISO 18869.
Tests outlined in this International Standard are independent of each other and document the method
to follow for each test. See the appropriate component International Standard for which tests to conduct
and for performance criteria.
For qualification of the connector, the minimum number of samples specified in this International
Standard is tested, unless otherwise specified in the relevant connector standard or as agreed upon by
the manufacturer and the user.
2 Normative references
The following referenced documents are indispensable for the application 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 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and
100 IRHD)
ISO 3448, Industrial liquid lubricants — ISO viscosity classification
ISO 3601-3, Fluid power systems — O-rings — Part 3: Quality acceptance criteria
ISO 5598, Fluid power systems and components — Vocabulary
ISO 6508 (all parts), Metallic materials — Rockwell hardness test
ISO 6605, Hydraulic fluid power — Test methods for hoses and hose assemblies
ISO 6743-4, Lubricants, industrial oils and related products (class L) — Classification — Part 4: Family H
(Hydraulic systems)
ISO 10763, Plain-end, seamless and welded precision steel tubes -- Dimensions and nominal working
pressures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 apply.
4 General requirements
WARNING — Some of the tests described in this International Standard are considered hazardous.
It is, therefore, essential that, in conducting these tests, all appropriate safety precautions be
strictly adhered to. Attention is drawn to the danger of burst, fine jets (which can penetrate the
skin) and energy release of expanding gases. To reduce the hazard of energy release, bleed air
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out of test specimens prior to pressure testing. Tests shall be set up and performed by properly
trained personnel.
4.1 Test assemblies
All components tested shall be in the final form, including annealed nuts, as required for brazed
components. Unless otherwise specified in the respective connector standard, Type 1 test assemblies
shall be as shown in Figure 1 for tube connections (for repeated assembly, leakage, proof, burst and
cyclic endurance tests), and Type 2 test assemblies shall be as shown in Figure 2 for male stud ends
(for leakage, proof and, if specified, burst and cyclic endurance tests). Alternatively, in order to test the
connector to its full capability, use of the metallic tube may be omitted for burst and cyclic endurance
tests, and different configurations with similar capability may be combined in a test assembly Type 3,
as shown in Figure 3. Type 4 test assemblies for flange connectors shall be as shown in Figure 4. Test
assemblies shall conform to the relevant requirements given in Table 1.
Table 1 — Requirements for test assemblies
Part code Part name Description and further information
The type of stud end, tube-connector end and sealing method
A Straight stud connector
is optional but shall be recorded in the test report.
The required tube wall thickness shall be selected according
to the working pressure rating of the respective connec-
tor. The working pressure of the tube in accordance with
B Metallic tube
ISO 10763 shall be equal to or slightly greater than the work-
ing pressure of the respective connector. The length of the
tube shall be five times the tube outside diameter plus 50 mm.
Shaped connector, with
C —
swivel, if applicable
D Blanking end (cap or plug) —
Shaped connector with
E —
adjustable stud end
F Flange connector —
G Sealing e.g. O-ring.

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Key
1 swivel nut
A straight stud connector
B metallic tube
C shaped connector
D blanking end (cap or plug)
G sealing, e.g. O-ring
a
L = 5 × the tube OD (in millimetres) + 50 mm.
Figure 1 — Typical test assembly for tube connection — Type 1est assembly for tube
connection — Type 1
a) Non-adjustable stud end connection b) Adjustable stud end connection, with
shaped connector, if applicable
Key
A straight stud connector
D blanking end (cap or plug)
E shaped connector with adjustable stud end
G sealing, e.g. O-ring
Figure 2 — Typical test assembly for stud end — Type 2est assembly for stud end — Type 2
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Key
1 swivel nut
C shaped connector with swivel
D blanking end (cap or plug)
E shaped connector with adjustable stud end
G sealing, e.g. O-ring
Figure 3 — Typical test assembly without tube — Type 3test assembly without tube — Type 3
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Key
1 O-ring seal
2 split-flange clamp
3 screw
4 washer
5 test adapter
F flange connector
a
This end capped or plugged.
Figure 4 — Typical test assembly for flange connectors — Type 4est assembly for flange
connectors — Type 4
4.2 Test equipment
4.2.1 Test block
Test blocks shall be unplated and have a hardness between 35 HRC and 45 HRC in accordance with
ISO 6508. For a test block with multiple ports, the distance between the centrelines of test ports shall
be a minimum of 1,5 times the port diameter. The distance between the port centreline and the edge of
the test block shall be a minimum of 1 times the port diameter.
4.2.2 Test seals
For all tests, except for the overtightening test and unless otherwise specified, seals shall be nitrile
(NBR) rubber with a hardness of (90 ± 5) IHRD when measured in accordance with ISO 48. Seals shall
conform to their respective dimensional requirements, and O-rings shall meet or exceed the quality
requirements for grade N (general purpose) of ISO 3601-3, if applicable.
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4.3 Procedure
4.3.1 Thread lubrication
For all tests, on connectors made of carbon steel and for testing only, threads and contact surfaces
shall be lubricated prior to application of torque using a hydraulic fluid with a viscosity of ISO VG 32 in
accordance with ISO 3448. For connectors made of materials other than carbon steel, the manufacturer's
recommendation for thread lubrication shall be followed.
4.3.2 Torque
For all tests, except the repeated assembly and overtightening tests, tube connections and stud ends
shall be tested at the required minimum torques or number of hex flats or turns from finger-tight
position given in the respective connector standard, if specified. Otherwise, they shall be tested at
the minimum torque values or number of hex flats or turns from finger-tight position supplied by the
manufacturer. For test assembly, type 2 and type 3 adjustable stud torques shall be applied after being
backed out one full turn from finger-tight, in order to test correctly the worst possible actual assembly
conditions.
4.3.3 Temperature
For all tests, the temperature of the hydraulic fluid shall be between 15 °C and 80 °C, unless otherwise
specified in the respective connector standard.
4.4 Test report
Test results and test conditions shall be reported on the test data form given in Annex A.
NOTE ISO/TR 11340 provides a method of reporting leakage.
5 Repeated assembly test
5.1 Principle
Unless otherwise specified in the respective connector standard, three type 1 test assemblies shall be
tested to confirm that they are capable of meeting the necessary requirements after being disassembled
and re-assembled several times.
5.2 Procedure
The tube connections of the straight stud connector (part A in Figure 1) and shaped connector (part C
in Figure 1) shall be disassembled and re-assembled six times. Prior to each re-assembly, the tube shall
be turned clockwise by 60°. On re-assembly, the nuts shall be tightened firmly, using the maximum
torque values or number of turns given in the respective connector standard or by the manufacturer.
All assemblies, after the first and sixth re-assembly, shall be subjected to a leakage test (Clause 6) and a
proof test (Clause 7) at the test parameters specified in Table 2.
Table 2 — Parameters and procedure for repeated assembly test
Test parameter Value of parameter and procedure
Test medium
Test pressure As specified in Clauses 6 and 7.
Test duration
Pass/fail criterion Any leakage during the leakage and proof tests shall be considered a failure.
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5.3 Re-use of components
Parts that pass this test may be used for burst and cycle endurance tests at the minimum specified
assembly torque or number of turns. They shall not be used for actual service or returned to stock.
6 Leakage test
6.1 Principle
Unless otherwise specified in the respective connector standard, all type 1 test assemblies from the
repeated assembly test and three each of type 2, type 3 and type 4 assemblies (where applicable) shall
be subjected to a leakage test to ensure that assemblies do not leak when subjected to test pressure.
6.2 Procedure
Test assemblies shall be pressurized under water as shown in Figure 5 and described in Table 3.
Key
1 test fluid inlet
2 water
Figure 5 — Typical test set-up for leakage test
Table 3 — Parameters and procedure for leakage test
Test parameter Value of parameter and procedure
Air, nitrogen or helium.
Test medium
The test medium shall be recorded in the test report.
The test pressure shall be increased continuously until the pressure reaches
Test pressure a level equal to 15 % of the connector's working pressure, in accordance with
a
the respective standard, where applicable, not exceeding 6,3 MPa (63 bar ).
A minimum of 3 min at the test pressure, after all of the air trapped in the con-
Test duration
nector's threads during test set-up has escaped.
Leakage, in the form of ascending bubbles, shall not occur in any of the test
Pass/fail criterion
assemblies.
a 5 2
1 bar = 0,1 MPa = 10 Pa; 1 MPa = 1 N/mm .
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6.3 Re-use of components
Parts that pass this test may be used for further tests. They shall not be used for actual service or
returned to stock.
7 Proof test
7.1 Principle
Unless otherwise specified in the respective connector standard, three type 1 test assemblies and,
where applicable, three type 2, type 3 and type 4 test assemblies shall be tested to confirm that the
specified connections are capable of withstanding a minimum of two times the working pressure
without any visual sign of leakage.
7.2 Procedure
The test assemblies shall be pressurized as shown in Figure 6 at the test parameters specified in Table 4.
Air shall be carefully bled from the test assemblies before applying static pressure.
Key
1 test fluid inlet
2 air
Figure 6 — Typical test set-up for static proof pressure and burst test
Table 4 — Parameters and procedure for proof test
Test parameter Value of parameter and procedure
Hydraulic fluid in accordance with ISO 6743-4, e.g. HM, with a viscosity equal
to or less than ISO VG 32, in accordance with ISO 3448, or water.
Test medium
The test medium shall be recorded in the test report.
Two times the working pressure of th
...