1. General provisions
1.0.1 This national standard specifies nominal dimension, nominal pressure, material, pressure-temperature rating, flange type, dimension, seal contact face, tolerance and marking of larger diameter steel pipe flanges (Class designated).
1.0.2 This Standard is applicable to larger diameter weld neck steel pipe flanges and blind flanges with nominal pressure of Classl50 (PN20)~Class900 (PN150). The nominal pressure grade of the flange is denoted by Class, including the following four grades: Classl50, Class300, Class600 and Class900.
1.0.3 This Standard includes A and B two dimensions series of larger diameter steel pipe flange, and clear marking must be indicated when being adopted.
1.0.4 The applied nominal dimension DN and outside diameter of the steel pipe in this Standard are in accordance with those specified in Table 1.0.4.
... ...
... ...
1.0.5 This Standard is also applicable to valve, pump, chemical engineering machinery, pipeline fittings and equipment spares with flanges being used as type of attachment.
1.0.6 This Standard excludes selection principle for materials under particular fluid operating conditions.
2. Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this Standard. For dated reference, subsequent amendments (excluding content of corrigenda) to, or revisions of, any of these publications do not apply. However, Parties to agreements based on this Code are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document referred to applies.
"Fasteners-Counterbores for Hexagon Bolts and Nuts" GB/T 152.4
"Steel Pipe Flanges (Class Designated)" HG/T 20615
"Non-metallic Flat Gaskets for use with Steel Pipe Flanges (Class designated)" HG/T 20627
"PTFE Envelope Gaskets for use with Steel Pipe Flanges (Class designated)" HG/T 20628
"Metal Jacketed Gaskets for use with Steel Pipe Flanges (Class Designated)" HG/T 20630
"Spiral Wound Gaskets for use with Steel Pipe Flanges (Class Designated)" HG/T 20631
"Covered Serrated Metal Gaskets for use with Steel Pipe Flanges (Class Designated)" HG/T 20632
"Metallic Ring Joint Gaskets for use with Steel Pipe Flanges (Class Designated)" HG/T 20633
Contents
1. General provisions
2. Normative references
3. Type and seal contact face of the flanges
3.1 Flange type
3.2 Seal contact face of the flanges
4. Materials
5. Maximum allowable working pressure
6. Thickness of the straight flange
7. Dimension
8. Flange joint
9. Welding joint and groove dimension
10. Dimension tolerance
11. Test
12. Inspection and acceptance
13. Markings and illustrations
14. Packaging and steel seal labeling
Appendix A (Informative) Approximate Mass of Larger Diameter Pipe Flanges
Appendix B (Informative) Assorted Pipe Flanges' Standard
