1. General provisions
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.
"Pipework Components--Definition and Selection of DN (Nominal Dimension)" GB/T 1047
"Pipework Components--Definition and Selection of PN (Nominal Pressure)" GB/T 1048
"Steel Pressure Vessels" GB 150
"Fasteners-Clearance Holes and Counterbores" GB/T 152.1~152.4
"Carbon Structural Steels" GB/T 700
"Hot-rolled Quality Carbon Structural Steel Plates and Wide Strips" GB/T 711
"Steel Plates for Boiler and Pressure Vessels" GB 713
"Hot-rolled Plates and Strips of Carbon Structural Steels and High Strength Low Alloy Structural Steels" GB/T 3274
"Low Alloy Steel Plates for Low Temperature Pressure Vessels" GB 3531
"Hot Rolled Stainless Steel Plate Sheet and Strip" GB/T 4237
"Pipe Threads with 55 Degree Thread Angle where Pressure-tight Joints are Made on the Threads--Part 2: Taper Internal and External Threads" GB/T 7306.2
"General Purpose Industrial Valves-Specification of Carbon Steel Forgings" GB/T 12228
"General Purpose Industrial Valves-Specification of Carbon Steel Castings" GB/T 12229
"General Purpose Industrial Valve——Specification of Stainless Steel Castings" GB/T 12230
"Pipe Threads with the Thread Angle of 60 Degrees where Pressure-tight Joints are made on the Threads" GB/T 12716
"Steel Castings for Pressure Purposes" GB/T 16253
"Dimension Selection Series of Seamless and Welded Steel Pipe for Chemical Industry Piping" HG/T 20553
"Non-metallic Flat Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20606
"PTFE Envelope Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20607
"Metal Jacketed Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20609
"Spiral Wound Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20610
"Covered Serrated Metal Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20611
"Metallic Ring Joint Gaskets for use with Steel Pipe Flanges (PN designated)" HG/T 20612
"Bolting for use with Steel Pipe Flanges (PN designated)" HG/T 20613
"Specification for selection of Steel Pipe Flanges, Gaskets and Bolting (PN designated)" HG/T 20614
"Welding Specification for Steel Pressure Vessels" JB/T 4709
"Carbon and Low-alloy Steel Forgings for Pressure Vessels" JB 4726
"Low-alloy Steel Forgings for Low Temperature Pressure Vessels" JB 4727
"Stainless Steel Forgings for Pressure Vessels" JB 4728
"Nondestructive Testing of Pressure Vessels" JB/T 4730
"Specification for Steel Casting for Power Station Valves" JB/T 5263
"Technical Specification for Low Temperature Service Steel Casting for Valves" JB/T 7248
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).
... ...
... ...
