1 Scope
This standard gives the definition of nominal size when applied to components of a pipework system, and specifies the nominal size series used for pipework components.
This standard is applicable to pipework components whose nominal size is designated by DN.
2 Terms and definitions
For the purposes of this document, the following term and definition apply.
2.1
nominal size
an alphanumeric designation of size for components of a pipework system, which is used for reference purposes and comprises the letters DN followed by a dimensionless whole number
Notes:
1 This dimensionless number is directly related to the physical size (in mm), of the bore or outside diameter of the end connections.
2 The number following the letters DN does not represent a measurable value and shall not be used for calculation purposes except where specified in the relevant standard.
3 Nominal size series and selection
3.1 The preferred nominal size values are as follows:
DN 6 DN 80 DN 500 DN 1000 DN 1800 DN 2800
DN 8 DN 100 DN 550 DN 1050 DN 1900 DN 2900
DN 10 DN 125 DN 600 DN 1100 DN 2000 DN 3000
DN 15 DN 150 DN 650 DN 1150 DN 2100 DN 3200
DN 20 DN 200 DN 700 DN 1200 DN 2200 DN 3400
DN 25 DN 250 DN 750 DN 1300 DN 2300 DN 3600
DN 32 DN 300 DN 800 DN 1400 DN 2400 DN 3800
DN 40 DN 350 DN 850 DN 1500 DN 2500 DN 4000
DN 50 DN 400 DN 900 DN 1600 DN 2600
DN 65 DN 450 DN 950 DN 1700 DN 2700
3.2 In those standards which use the DN designation system, any relationship between DN and component dimensions shall be given, e.g., DN/OD or DN/ID.
3.3 Other methods of size designation different from that in this standard are also used, e.g., components of a pipework system designated by NPS (nominal pipe size), OD (outside diameter), ID (inside diameter). See Annex A for the corresponding relation between the nominal size DN and NPS.
Foreword i
1 Scope
2 Terms and definitions
3 Nominal size series and selection
Annex A (Informative) Corresponding relation between nominal size DN and NPS
