ISO 9691:1992

INTERNATIONAL
STANDARD
First edition
1992-11-15
-
~~.~-~-~--~~~~,~___- .---- ---
Rubber - Recommendations for the
workmanship of pipe joint rings - Description
and classification of imperfections
Recommandations concernant l’execution des garnitures
Caoutct?ouc -
- Description et classifkation
d’6iancMft5 pour joint de canalisafion
des imper-fections
Reference number
ISO 9691: 1992( E)

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ISO 9691:1992(E)
Foreward
ISO (the International Organization for Standardization) is a woridwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical cornmittees. Esch 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, govern-
mental and non-governmental, in liaison with ISO, also take part in the
work. ISO collaborates closely with the International Etectrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Inter-
national Standard requires approval by at least 75 % of the member
bodies castinq a vote.
L
International Standard ISO 9691 was prepared by Technical Committee
ISO/TC 45, Rubber and rubber producfs, Sub-Committee SC 4, Miscel-
laneous products.
Annex A of this International Standard is for information only.
0 ISO 1992
All rights reserved. No part of this publication may be reproduced or utilized in any fort-n
or by any means, electronie or mechanical, including photocopying and microfilm, withorrt
permission in writing from the publisher.
International Organization for Standardization
Case Postale 36 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii

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ISO 9691:1992(E)
Introduction
International Standards such as ISO 4633P1, ISO 6447121 and ISO 6448M
(see bibliography) for rubber joint rings for pipelines include some gen-
eral requirements for the finished rings, pat-ticularly for workmanship,
in Statements such as: “The rings shall be free from porosity and shall
not have surface defects or irregularities which could affect their func-
tions”.
In Order to assist manufacturers wishing to comply with such require-
ments, this International Standard describes manufacturing imperfec-
tions which could arise during the production of pipe joint rings, and lists
criteria by which the quality of workrnanship tan be assessed. lt should
be stressed, however, that this International Standard is not a specifi-
cation. Whether an imperfection is to be considered as a defect will ul-
timately have to be agreed upon between the interested Parties (see
clause 4).
. . .
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- Recommendations for the workmanship of pipe
Rubber
- Description and classification of imperfections
joint rings
3.1.1 Imperfections not involving excess or
1 Scope
shortage of material
This International Standard describes and classifies
imperfections in rubber joint rings for pipelines.
3.1.1.1 Bloom: A liquid or solid material which has
migrated to the surface of a rubber.
2 Normative references
3.1.1.2 Surface inclusion (foreign material): Any
The following Standards contain provisions which,
extraneous matter embedded in the surface.
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All stan- 3.1.1.3 Cut: A fine incision similar to that made by
dards are subject to revision, and Parties to a scalpel. The tut is not open. lt is usually necessary
agreernents based on this International Standard to stretch the rubber for the edges of the tut to be-
are encouraged to investigate the possibility of ap- come clearly visible.
plying the most recent editions of the Standards in-
dicated below. Members of IEC and ISO maintain
3.1 .1.4 Cracking: A network of fine Cracks or
registers of currently valid International Standards.
crazing which is not visible unless the rubber is
folded. lt may be caused, for example, by ageing or
ISO 2781: 1988, Rubber, vulcanized - Determination
incorrect storage.
of densify.
ISO 7743~1989, Rubber, vulcanized or thermoplastic
-- Determination of compression stress-strain prop-
3.1.2 Excess material
erties.
3.1.2.1 Flash (see figure 1): Excess material which
3 Classification of imperfections
escapes from the moulding cavity during moulding
of a moulded ring, or is produced at the weld line
3.1 Surface imperfections
of an extruded welded ring, and solidifies to form a
film-Iike appendage. It is cau
...