ISO 8639:2000

INTERNATIONAL ISO
STANDARD 8639
First edition
2000-03-15
Glass-reinforced thermosetting plastics
(GRP) pipes and fittings — Test methods
for leaktightness of flexible joints
Tubes et raccords en plastiques thermodurcissables renforcés de verre
(PRV) — Méthodes d'essai d'étanchéité des assemblages flexibles
Reference number
ISO 8639:2000(E)
©
ISO 2000

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ISO 8639:2000(E)
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ii © ISO 2000 – All rights reserved

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ISO 8639:2000(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Principle.1
3 Apparatus .3
4 Test pieces .5
4.1 Test arrangement.5
4.2 Number of test pieces .5
5 Conditioning.5
6 Test temperature.5
7 Procedure .5
7.1 Sequence for testing .5
7.2 Initial leakage .5
7.3 Resistance to negative pressure.6
7.4 Simultaneous angular deflection and draw .6
7.5 Simultaneous misalignment and draw .7
7.6 Cyclic pressure .7
8 Test report .7
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ISO 8639:2000(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 8639 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and
valves for the transport of fluids, Subcommittee SC 6, Reinforced plastics pipes and fittings for all applications.
This standard is one of a series of standards on test methods which support standards for plastics piping systems
and ducting systems.
iv © ISO 2000 – All rights reserved

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ISO 8639:2000(E)
Introduction
In a pipework system, pipes and fittings of different nominal pressures and stiffnesses may be used.
Any joint made between pipes and/or fittings should be designed such that its performance is equal to or better
than the requirements of the pipeline, but not necessarily of the components being joined.
The requirements for assembly of the joint are not included in this International Standard, but they should be in
accordance with the manufacturer's recommendations.
The material-dependent parameters and/or performance requirements are stated in the referring specification.
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INTERNATIONAL STANDARD ISO 8639:2000(E)
Glass-reinforced thermosetting plastics (GRP) pipes and fittings —
Test methods for leaktightness of flexible joints
1 Scope
This International Standard specifies methods of test for flexible socket-and-spigot joints with elastomeric sealing
elements for glass-reinforced thermosetting plastics (GRP) piping systems intended for buried and above-ground
pipelines. It covers methods of test for the leaktightness of the joint only, when subjected to specified combinations
of longitudinal extension (draw), angular movement (angular deflection), vertical compression (misalignment) and
internal pressure. This International Standard is applicable to joints for either pressure or non-pressure
applications.
NOTE The joints tested in accordance with this International Standard are subjected to conditions which measure their
ability to function and thereby prove the design of the joint, especially for type-testing purposes.
These test procedures are applicable to joints for pipes and fittings of all nominal sizes. The tests are suitable for
the evaluation of joints intended for applications in which liquids are conveyed at temperatures specified in the
referring specifications (see clause 2).
2Principle
A test piece comprising two pieces of pipe jointed together by incorporation of a socket or inclusion of a double-
socket coupler is subjected to specified combinations of draw, angular deflection and misalignment. In each
specified combination, the test piece is subjected to a sequence of three or more test pressures for specified
periods of time, including an internal sub-atmospheric test pressure.
In addition, joints for pressure applications are subjected to a specified cyclic pressure test.
When under pressure, the joint is monitored for leakage.
Between each test (see Tables 1 and 2), the joint is inspected for signs of leakage.
NOTE 1 It is assumed that the following test parameters will be set by the specification making reference to this International
Standard:
a) the nominal size of the components to be connected by the joint (see 4.1);
b) the pressure class of the components (see 4.1);
c) the total effective length L of the assembled test piece (see 4.1);
d) thenumberoftestpiecestobeused(see4.2);
e) if applicable, any preconditioning other than that specified in clause 5;
f) the test temperature and the permissible deviations from the test temperature (see clause 6);
g) the nominal pressure relevant to the joint under test (see 4.1 and clause 7);
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ISO 8639:2000(E)
h) the joint positions (see Tables 1 and 2);
i) the draw (see 7.3.1, 7.4.3 and 7.5.2), the angular deflection (see 7.4.3) and the force F (see 7.5.5);
j) the acceptable increase in pressure over 1 h for the negative-pressure test (see 7.3).
NOTE 2 The only purpose in testing the resistance to negative pressure is to give adequate safety against infiltration of
pollutants through the joint into the fluid carried in the piping system. Under these test conditions, pipes with a low stiffness may
require support to prevent buckling.
If the joint is to be used in systems where the maximum operating temperature is higher than the value given in the
referring specification, the test conditions may be modified accordingly.
Table 1 — Summary of tests for evaluating joints for pressure applications — Conditions and sequence
Pressure Subclause
Test Pressure level Duration
sequence number
Initial leakage Initial pressure 1,5 � PN 15 min 7.2.4
Total draw Negative pressure – 0,8 bar 1 h 7.3.3 and 7.3.4
Preliminary
1,5 � PN 15 min 7.4.5
pressure
Angular deflection
and draw
Maintained
2,0 � PN 24 h 7.4.6
pressure
Preliminary
15 min 7.5.4
1,5 � PN
pressure
Misalignment and
draw
Maintained
2,0 � PN 24 h 7.5.7
pressure
Atmospheric to
10 cycles of
Positive cyclic 1,5 � PN and
Cyclic pressure 1,5 min to 3,0 min 7.6.2 and 7.6.3
pressure
back to
each
atmospheric
NOTE Nominal pressure (PN) is an alphanumeric designation of pressure related to the resistance of a
component of a piping system to internal pressure.
Table 2 — Summary of tests for evaluating joints for non-pressure applications — Conditions and
sequence
Pressure Subclause
Test Pressure level Duration
sequence number
Initial leakage Initial pressure 1,5 bar 15 min 7.2.4
Total draw Negative pressure – 0,8 bar 1 h 7.3.3 and 7.3.4
Preliminary
1,5 bar 15 min 7.4.5
pressure
Angular deflection
and draw
Maintained
2,0 bar 24 h 7.4.6
pressure
Preliminary
1,5 bar 15 min 7.5.4
pressure
Misalignment
...