SIST ISO 6708:1995
(Main)Pipework components -- Definition and selection of DN (nominal size)
Pipework components -- Definition and selection of DN (nominal size)
Cancels and replaces the first edition (1980). Gives the definition of DN (nominal size) when applied to components of a pipework system, as specified in those standards which use the DN designation system. Gives a list of preferred DN values.
Composants de réseau de tuyauteries -- Définition et sélection des DN (diamètre nominal)
La présente Norme internationale donne la définition de DN (diamètre nominal) lorsqu'elle est appliquée à des composants d'un réseau de tuyauteries, comme spécifié dans celles des normes qui utilisent le système de désignation par DN. NOTE 1 D'autres méthodes de désignation de dimension sont aussi utilisées, par exemple produits ayant des extrémités à raccordements filetés, à compression, brasés ou soudés, ou produits désignés par NPS (dimension nominale du tube), DE (diamètre extérieur), DI (diamètre intérieur), mais celles-ci ne sont pas définies dans la présente Norme internationale. La présente Norme internationale donne une liste des valeurs de DN préférentielles.
Cevni deli - Opredelitve in izvor imenskih mer
General Information
- Status
- Published
- Publication Date
- 31-Oct-1995
- Technical Committee
- TLP - Pressure vessels
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 01-Nov-1995
- Due Date
- 01-Nov-1995
- Completion Date
- 01-Nov-1995
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ISO 6708:1995 - Pipework components — Definition and selection of DN (nominal size) Released:6/22/1995
ISO 6708:1995 - Composants de réseau de tuyauteries — Définition et sélection des DN (diametre nominal) Released:6/22/1995
ISO 6708:1995 - Composants de réseau de tuyauteries — Définition et sélection des DN (diametre nominal) Released:6/22/1995
Relations
- Consolidates
SIST EN ISO 6708:1998 - Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995) - Effective Date
- 12-Feb-2026
- Effective Date
- 15-Apr-2008
Overview
SIST ISO 6708:1995 is an important international standard for the piping industry, titled Pipework Components - Definition and Selection of DN (Nominal Size). Published by SIST, this standard specifies the definition of DN (nominal size) for components used in pipework systems. It provides a consistent system for referencing pipe sizes, ensuring clarity and interoperability among manufacturers, suppliers, and engineering professionals worldwide.
Replacing the first edition from 1980, the 1995 revision incorporates updated definitions and an expanded list of preferred DN values. The standard is essential for anyone involved in the design, manufacturing, or specification of metallic pipes and fittings, particularly where the DN designation system is applied.
Key Topics
- Definition of DN (Nominal Size):
- DN is an alphanumeric size designation for pipework components, represented as "DN" followed by a dimensionless whole number. It is indirectly related to the physical bore or outside diameter of pipe ends.
- The DN figure is primarily for reference and not a directly measurable value unless specified in related standards.
- Preferred DN Values:
- SIST ISO 6708:1995 includes a comprehensive list of preferred DN values, ranging from DN 10 up to DN 4,000.
- Designation System Usage:
- The standard addresses the relationship between DN and component dimensions such as outer diameter (OD) or inner diameter (ID) when applied within other relevant standards.
- Distinction from Other Sizing Methods:
- DN is distinguished from other size designation methods such as NPS (nominal pipe size), OD (outside diameter), and ID (inside diameter), which are not defined within this standard.
Applications
- Piping System Specification:
- DN is widely used for specifying pipework components such as pipes, valves, flanges, and fittings across various industries including water supply, HVAC, petrochemical, and industrial process systems.
- Product Interchangeability:
- Adopting the DN size system improves product compatibility and interchangeability among different manufacturers and regions.
- Standardized Documentation:
- DN references streamline technical documentation and enable accurate communication of design requirements across multidisciplinary teams.
- Procurement and Supply Chain:
- Clearly specified DN sizes facilitate smoother procurement processes and inventory management for pipework components.
- Compliance and Quality Assurance:
- Utilizing components labeled with standardized DN sizes ensures compliance with international norms, supporting consistent safety and performance benchmarks.
Related Standards
When working with SIST ISO 6708:1995, consider these related international standards for a comprehensive approach to piping and pipework component specification:
- ISO 7005: Metallic flanges - General requirements and dimensions
- ISO 4200: Plain end steel tubes, welded and seamless - General table of dimensions and masses per unit length
- ISO 3126: Plastics piping systems - Measurement of dimensions
- ISO 4161: Steel tube, non-ferrous tube - Size designation systems
These standards complement ISO 6708 by providing additional dimensional, material, and connection standards for pipes and associated components.
Keywords: pipework components, DN nominal size, piping standard, ISO 6708, selection of DN, dimensioning, piping systems, size designation, standardization, metallic pipes, SIST
Buy Documents
ISO 6708:1995 - Pipework components — Definition and selection of DN (nominal size) Released:6/22/1995
ISO 6708:1995 - Composants de réseau de tuyauteries — Définition et sélection des DN (diametre nominal) Released:6/22/1995
ISO 6708:1995 - Composants de réseau de tuyauteries — Définition et sélection des DN (diametre nominal) Released:6/22/1995
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Frequently Asked Questions
SIST ISO 6708:1995 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Pipework components -- Definition and selection of DN (nominal size)". This standard covers: Cancels and replaces the first edition (1980). Gives the definition of DN (nominal size) when applied to components of a pipework system, as specified in those standards which use the DN designation system. Gives a list of preferred DN values.
Cancels and replaces the first edition (1980). Gives the definition of DN (nominal size) when applied to components of a pipework system, as specified in those standards which use the DN designation system. Gives a list of preferred DN values.
SIST ISO 6708:1995 is classified under the following ICS (International Classification for Standards) categories: 23.040.01 - Pipeline components and pipelines in general. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST ISO 6708:1995 has the following relationships with other standards: It is inter standard links to SIST EN ISO 6708:1998, ISO 6708:1980. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST ISO 6708:1995 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-1995
Cevni deli - Opredelitve in izvor imenskih mer
Pipework components -- Definition and selection of DN (nominal size)
Composants de réseau de tuyauteries -- Définition et sélection des DN (diamètre
nominal)
Ta slovenski standard je istoveten z: ISO 6708:1995
ICS:
23.040.01 Deli cevovodov in cevovodi Pipeline components and
na splošno pipelines in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL
STANDARD
Second edition
1995-07-01
Pipework components - Definition and
selection of DN (nominal size)
Composants de r&eau de tuyauteries - Dgfinition et s&ection des DN
(diam&re nominal)
Reference number
IS0 6708: 1995(E)
IS0 6708:1995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical 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 International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 6708 was prepared by Technical Committee
lSO/TC 5, Ferrous metal pipes and metallic fittings, Subcommittee SC 10,
Metallic flanges and their joints.
This second edition cancels and replaces the first edition
(IS0 6708:1980), which has been technically revised and enlarged by the
inclusion of clause 3.
0 IS0 19
...
INTERNATIONAL
STANDARD
Second edition
1995-07-01
Pipework components - Definition and
selection of DN (nominal size)
Composants de r&eau de tuyauteries - Dgfinition et s&ection des DN
(diam&re nominal)
Reference number
IS0 6708: 1995(E)
IS0 6708:1995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical 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 International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard IS0 6708 was prepared by Technical Committee
lSO/TC 5, Ferrous metal pipes and metallic fittings, Subcommittee SC 10,
Metallic flanges and their joints.
This second edition cancels and replaces the first edition
(IS0 6708:1980), which has been technically revised and enlarged by the
inclusion of clause 3.
0 IS0 1995
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronic or mechanical, including photocopying and
microfilm, without permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
INTERNATIONAL STAND
...
NORME
Iso
INTERNATIONALE 6708
Deuxième édition
1995-07-01
Composants de réseau de tuyauteries -
Définition et sélection des DN (diamètre
nominal)
- Definition and selection of DN (nominal size)
Pipework componen ts
Numéro de référence
ISO 6708: 1995(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération
mondiale d’organismes nationaux de normalisation (comités membres de
I’ISO). L’élaboration des Normes internationales est en général confiée aux
comités techniques de I’ISO. Chaque comité membre intéressé par une
étude a le droit de faire partie du comité technique créé à cet effet. Les
organisations internationales, gouvernementales et non gouvernemen-
tales, en liaison avec I’ISO participent également aux travaux. L’ISO colla-
bore étroitement avec la Commission électrotechnique internationale (CEI)
en ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques
sont soumis aux comités membres pour vote. Leur publication comme
Normes internationales requiert l’approbation de 75 % au moins des co-
mités membres votants.
La Norme internationale ISO 6708 a été élaborée par le comité technique
ISOfK 5, Tuyauteries en métaux ferreux et raccords métalliques, sous-
comité SC 10, Brides métalliques et leurs assemblages.
Cette deuxième édition annule et remplace la première édition
(ISO 6708:1980), dont elle constitue une révision technique et une ex-
tension par l’ajout de l’article 3.
0 ISO 1995
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publi-
cation ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun pro-
cédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l’accord
écrit de l’éditeur.
Organisation internationale de normalisation
Case Postale 56 l CH-l 211 Genève 20 l Suisse
Imprimé en Suisse
II
NORME INTERNATIONALE 0 ISO ISO 6708:1995(F)
- Définition et
Composants de réseau de tuyauteries
sélection d
...
NORME
Iso
INTERNATIONALE 6708
Deuxième édition
1995-07-01
Composants de réseau de tuyauteries -
Définition et sélection des DN (diamètre
nominal)
- Definition and selection of DN (nominal size)
Pipework componen ts
Numéro de référence
ISO 6708: 1995(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération
mondiale d’organismes nationaux de normalisation (comités membres de
I’ISO). L’élaboration des Normes internationales est en général confiée aux
comités techniques de I’ISO. Chaque comité membre intéressé par une
étude a le droit de faire partie du comité technique créé à cet effet. Les
organisations internationales, gouvernementales et non gouvernemen-
tales, en liaison avec I’ISO participent également aux travaux. L’ISO colla-
bore étroitement avec la Commission électrotechnique internationale (CEI)
en ce qui concerne la normalisation électrotechnique.
Les projets de Normes internationales adoptés par les comités techniques
sont soumis aux comités membres pour vote. Leur publication comme
Normes internationales requiert l’approbation de 75 % au moins des co-
mités membres votants.
La Norme internationale ISO 6708 a été élaborée par le comité technique
ISOfK 5, Tuyauteries en métaux ferreux et raccords métalliques, sous-
comité SC 10, Brides métalliques et leurs assemblages.
Cette deuxième édition annule et remplace la première édition
(ISO 6708:1980), dont elle constitue une révision technique et une ex-
tension par l’ajout de l’article 3.
0 ISO 1995
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publi-
cation ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun pro-
cédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l’accord
écrit de l’éditeur.
Organisation internationale de normalisation
Case Postale 56 l CH-l 211 Genève 20 l Suisse
Imprimé en Suisse
II
NORME INTERNATIONALE 0 ISO ISO 6708:1995(F)
- Définition et
Composants de réseau de tuyauteries
sélection d
...















