1.0.1 This national standard specifies the basic technical requirements of steel pipe flanges (PN designated), including nominal dimension, nominal pressure, material, pressure-temperature rating, flange type, dimension, seal contact face, tolerance and marking.
1.0.2 This Standard is applicable to steel pipe flanges and blind flanges in nominal pressure of PN2.5~PN160. The nominal flange pressure grades are denoted by PN, including the following nine grades: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100 and PN160.
1.0.3 Nominal dimension and outside diameter of the steel pipe
Outside diameter of the steel pipe applicable to this Standard includes two series: A and B, where A designs for the international purposes (it is commonly referred to as "John Guest"), while B designs for the domestic adopting series (it is commonly referred to as "metric pipe"). Its nominal dimension DN and outside diameter of the steel pipe are in accordance with those specified in Table 1.0.3.
The flanges adopting B series steel pipe shall be marked with "B" at the back of the number of nominal dimension DN for differentiation. However, the flange adopting A series steel pipe must not be marked with "A" at the back of the number of nominal dimension DN, for more details, see Chapter 13 and Chapter 14 of this Standard.
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.
3. Flange type and flange seal contact face
3.1 Flange type
3.1.1 The flange type and its code are in accordance with those specified in Figure 3.1.1 and Table 3.1.1. The flange type includes: plate-type flat welding flange (PL), slip-on neck flange (SO), welding neck flange (WN), integral type flange, socket welding flange (SW), thread flange (TH), butt welding ring loose flange (PJ/SE), flat welding ring loose flange (PJ/PR) , blind flange (BL) and lining blind flange (BL).
1. General provisions 2. Normative references 3. Flange type and flange seal contact face 3.1 Flange type 3.2 Flange seal contact face 4. Materials 5. Gaskets and bolting for flange 6. Fitting of flange joint 7. Pressure-temperature rating 8. Dimensions 8.1 Flanged coupling dimension 8.2 Physical dimension of the flange 8.3 Flange neck 8.4 Pipe thread 9. Welding joint and groove dimension 9.1 Plate-type flat welding flange and flat welding ring loose flange 9.2 Slip on neck flange 9.3 Welding joint of the socket welding flange connecting to the steel pipe 9.4 Weld neck flange 9.5 Butt welding ring 10. Dimension tolerance 11. Test 12. Inspection and acceptance 13. Marking and marking illustration 14. Packaging and steel seal label Appendix A (Normative) Steel Orifice Flange Appendix B (Informative) Steel Jacket Flange Appendix C (Informative) Assorted Pipe Flanges' Standard Appendix D (Informative) Approximate Mass of the Flange Appendix E (Informative) Approximate Distance between Ring Joint Face Flanges
