This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 1048-2005 Pipework components - Definition and selection of PN. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 1048-2005:
——The definition of nominal pressure designated by Class is added (see Clause 2);
——The nominal pressure PN 160, PN 250, PN 320 and PN 400 are added (see Table 1);
——PN 20, PN 50, PN 110, PN 150, PN 260 and PN 420 are deleted and replaced with Class 150, Class 300, Class 600, Class 900 and Class 1500 (see Table 1; Clause 3 of Edition 2005);
——The preferred values of Class designated are added (see Table 1).
This standard is redrafted by reference to but is not equivalent to ISO 7268:1983 Pipe components - Definition of nominal pressure.
This standard was proposed by the China Machinery Industry Federation.
This standard is under the jurisdiction of SAC/TC 237 National Technical Committee on Pipeline Fittings of Standardization Administration of China.
The previous editions of this standard are as follows:
——GB/T 1048-1970, GB/T 1048-1990 and GB/T 1048-2005.
Pipework components - Definition and selection of nominal pressure
1 Scope
This standard gives the definition of nominal pressure when applied to components of a pipework system, and states the nominal pressure series for use with these same components.
This standard is applicable to piping components whose nominal pressure is designated by PN or Class.
2 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
2.1
nominal pressure
an alphanumeric designation related to the mechanical properties and dimensional characteristics of components of a pipework system, which comprises the letters PN or Class followed by a dimensionless number
Note 1: The dimensionless number does not represent a measurable value and shall not be used for calculation purposes except where specified in the relevant standard.
Note 2: The letters PN or Class have no meaning except in relation to the relevant standards of pipework components.
Note 3: The maximum permissible working pressure of pipework components depends on PN or Class, material, design and maximum permissible working temperature of pipework components.
Note 4: The pipework components designated by the same PN or Class and DN numbers shall have the same connection dimensions as the flanges to which they are fitted.
3 Nominal pressure series and selection
The nominal pressure are designated by PN or Class. Nominal pressure values shall be selected from Table 1.
Foreword I
1 Scope
2 Terms and definitions
3 Nominal pressure series and selection
This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 1048-2005 Pipework components - Definition and selection of PN. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 1048-2005:
——The definition of nominal pressure designated by Class is added (see Clause 2);
——The nominal pressure PN 160, PN 250, PN 320 and PN 400 are added (see Table 1);
——PN 20, PN 50, PN 110, PN 150, PN 260 and PN 420 are deleted and replaced with Class 150, Class 300, Class 600, Class 900 and Class 1500 (see Table 1; Clause 3 of Edition 2005);
——The preferred values of Class designated are added (see Table 1).
This standard is redrafted by reference to but is not equivalent to ISO 7268:1983 Pipe components - Definition of nominal pressure.
This standard was proposed by the China Machinery Industry Federation.
This standard is under the jurisdiction of SAC/TC 237 National Technical Committee on Pipeline Fittings of Standardization Administration of China.
The previous editions of this standard are as follows:
——GB/T 1048-1970, GB/T 1048-1990 and GB/T 1048-2005.
Pipework components - Definition and selection of nominal pressure
1 Scope
This standard gives the definition of nominal pressure when applied to components of a pipework system, and states the nominal pressure series for use with these same components.
This standard is applicable to piping components whose nominal pressure is designated by PN or Class.
2 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
2.1
nominal pressure
an alphanumeric designation related to the mechanical properties and dimensional characteristics of components of a pipework system, which comprises the letters PN or Class followed by a dimensionless number
Note 1: The dimensionless number does not represent a measurable value and shall not be used for calculation purposes except where specified in the relevant standard.
Note 2: The letters PN or Class have no meaning except in relation to the relevant standards of pipework components.
Note 3: The maximum permissible working pressure of pipework components depends on PN or Class, material, design and maximum permissible working temperature of pipework components.
Note 4: The pipework components designated by the same PN or Class and DN numbers shall have the same connection dimensions as the flanges to which they are fitted.
3 Nominal pressure series and selection
The nominal pressure are designated by PN or Class. Nominal pressure values shall be selected from Table 1.
Contents of GB/T 1048-2019
Foreword I
1 Scope
2 Terms and definitions
3 Nominal pressure series and selection
