SIST EN ISO 6708:1998

Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995)

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.

Rohrleitungsteile - Definition und Auswahl von DN (Nennweite) (ISO 6708:1995)

Diese Norm legt die Definition von DN (Nennweite) bei Bauteilen von Rohrleitungen fest, die in Normen, die das DN-System verwenden, festgelegt sind. Anmerkung 1: Andere Bezeichnungsweisen sind auch gebräuchlich, z.B. Erzeugnisse mit Gewinde oder Schneidringverbindungen, gelöteten oder geschweißten Verbindungen oder Erzeugnisse die mit NPS, OD (Außendurchmesser) oder ID (Innendurchmesser) bezeichnet sind, diese sind jedoch nicht in dieser Norm definiert.

Composants de réseau de tuyauteries - Définition et sélection des DN (diametre nominal) (ISO 6708:1995)

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.

Elementi za cevovode - Definicija in izbira DN (imenski premer) (ISO 6708: 1995)

General Information

• Status: Published
• Publication Date: 30-Sep-1998
• ICS: 23.040.01 - Pipeline components and pipelines in general
• Technical Committee: TLP - Pressure vessels
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-1998
• Due Date: 01-Oct-1998
• Completion Date: 01-Oct-1998
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 89/106/EEC - Construction products
• Directive: 90/531/EEC - Procurement procedures of entities operating in the water, energy, transport and telecommunications sectors
• Directive: 93/38/EEC - Procurement procedures of entities operating in the water, energy, transport and telecommunications sectors
• Directive: 97/23/EC - Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Mandate: M/BC/CEN/88/15 - Standardization request to CEN/CENELEC in the field of Water supply, drainage and sewerage
• Ref Project: EN ISO 6708:1995 - Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995)

Overview

EN ISO 6708:1995 - “Pipework components - Definition and selection of DN (nominal size)” is an international standard (adopted by CEN) that defines the DN (nominal size) designation used for pipework system components. The second edition (1995) cancels and replaces the first edition (1980) and expands the standard by adding clarification (clause 3). It provides the formal definition of DN, guidance for its use in component standards, and a list of preferred DN values for consistent specification.

Key Topics

• Definition of DN: DN is an alphanumeric designation composed of the letters “DN” followed by a dimensionless whole number. This number is indirectly related to the physical size (bore or outside diameter) of end connections and is used for reference purposes.
• Dimensionless nature: The DN number does not represent a direct measurable value and should not be used for engineering calculations unless the relevant product standard explicitly specifies a relationship (e.g., DN/OD or DN/ID).
• Preferred DN series: The standard lists preferred DN values to standardize sizing across components. Examples include DN 10, 15, 20, 25, 32, 40, 50, 65, 80, 100 up to large sizes such as DN 1000, DN 2000 and beyond (full list contained in the standard).
• Usage guidance: Where a relationship between DN and actual dimensions is required (for example DN/OD or DN/ID), that relationship should be stated in the product-specific standard that uses the DN designation.

Applications

EN ISO 6708:1995 is widely used to ensure consistent size designation across pipework components such as:

• Flanges, fittings and metallic joints
• Valves, meters and pipeline accessories
• Component datasheets, procurement specifications and technical drawings

Who uses it:

• Mechanical and piping engineers
• Standards writers and product designers
• Manufacturers of pipes, fittings and valves
• Specifiers, purchasers and construction contractors
• Regulatory bodies and conformity assessors

Related Standards

• ISO 6708:1995 is the International Standard adopted by CEN as EN ISO 6708:1995.
• The standard notes other sizing methods (for example NPS, OD, ID or thread-based designations) exist and may be used in relevant standards; users should refer to product-specific standards for any DN-to-dimension relationships.

Keywords: EN ISO 6708:1995, DN nominal size, nominal diameter, pipework components, DN selection, preferred DN values, DN/OD, DN/ID.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-1998
Elementi za cevovode - Definicija in izbira DN (imenski premer) (ISO 6708: 1995)
Pipework components - Definition and selection of DN (nominal size) (ISO 6708:1995)
Rohrleitungsteile - Definition und Auswahl von DN (Nennweite) (ISO 6708:1995)
Composants de réseau de tuyauteries - Définition et sélection des DN (diametre
nominal) (ISO 6708:1995)
Ta slovenski standard je istoveten z: EN 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
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