Steel pipe flanges - Part 2: Class designated
1 Scope
This part of GB/T 9124 specifies the styles and parameters, types and sizes, technical requirements, test, inspection and acceptance, signs and designations, and supply requirements of Class designated steel pipe flanges and blind flanges.
This part is applicable to steel pipe flanges and blind flanges with nominal pressure of Class150 to Class2500 and nominal size of DN15 to DN600(NPS½ to NPS24).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 152.4 Fasteners - Counterbores for hexagonbolts and nuts
GB/T 700 Carbon structural steels
GB/T 711 Hot-rolled quality carbon structural steel plates, sheets and wide strips
GB 713 Steel plates for boilers and pressure vessels
GB/T 1047 Pipework components - Definition and selection of nominal size
GB/T 1048 Pipework components - Definition and selection of nominal pressure
GB/T 1804 General tolerances - Tolerances for linear and angular dimensions without individual tolerance indications
GB/T 3274 Hot-rolled plates and strips of carbon structural steels and high strength low alloy structural steels
GB 3531 Low alloy steel plates for low temperature pressure vessels
GB/T 4237 Hot rolled stainless steel plate, sheet and strip
GB/T 7306.1 Pipe threads with 55 degree thread angle where pressure-tight joints are made on the threads - Part 1: Parallel internal and taper external threads
GB/T 9125 Fasteners for pipe flange joints
GB/T 12228 General purpose industrial valves - Specification of carbon steel forgings
GB/T 12229 General purpose industrial valves - Specification of carbon steel castings
GB/T 12230 General purpose industrial valves - Specification of stainless steel castings
GB/T 12716 Taper pipe threads with 60 degree
GB/T 16253 Steel castings for pressure purposes
JB 4743 Nickel-copper alloy forgings for pressure vessels
JB/T 5263 Specification for steel casting for power station valves
JB/T 7248 Technical specification for low temperature service steel casting for valves
JB/T 9625 Specification for pressure retaining casting of boiler pipe fittings
NB/T 47008 Carbon and alloy steel forgings for pressure equipment
NB/T 47009 Low-alloy steel forgings for low temperature pressure equipment
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
3 Types and parameters
3.1 Nominal pressure
3.1.1 See GB/T 1048 for the definition of nominal pressure.
3.1.2 This part specifies the following 6 Class designated pressure grades:
Class150 Class300 Class600 Class900 Class1500 Class2500
3.2 Nominal size
3.2.1 See GB/T 1047 for the definition of nominal size.
3.2.2 This part specifies the following 20 DN(NPS) designated nominal sizes:
DN15 (NPS½), DN20 (NPS3/4), DN25 (NPS1), DN32 (NPS1/4), DN40 (NPS1½), DN50 (NPS2), DN65 (NPS2½), DN80 (NPS3), DN100 (NPS4), DN125 (NPS5), DN150 (NPS6), DN200 (NPS8), DN250 (NPS10), DN300 (NPS12), DN350 (NPS14), DN400 (NPS16), DN450 (NPS18), DN500 (NPS20), DN550 (NPS22), DN600 (NPS24).
3.3 Outside diameter of steel pipe
Series I outside diameters of steel pipe are applicable to this part. The nominal size of steel pipe flanges and the outside diameter of steel pipe shall meet the requirements of Table 1.
Table 1 Nominal size and outside diameter of steel pipe In: mm
3.4 Types and codes of flanges
See Table 2 for types and codes of flanges.
Table 2 Types and codes of flanges
Type of flange Integral flange Hubbed threaded flange Welding neck flange
Flange type code IF Th WN
Flange sketch
Type of flange Hubbed slip-on flange Hubbed socket welding flange Loose hubbed flange with welding neck-collar
Flange type code SO SW LHL
Flange sketch
Type of flange Blind flange
Flange type code BL
Flange sketch
3.5 Types and codes of sealing faces
The types and codes of sealing faces of flanges shall meet the requirements of Table 3.
Table 3 Types and codes of sealing faces
Sealing face type Code Sketch
Flat face FF
Raised face RF
Female and male faces Male face MF M
Female face F
Tongue and groove faces Tongue face TG T
Groove face G
Ring joint face RJ
3.6 Flange types and their application scope
The flange types and their application scope shall meet the requirements of Table 4, in which "√" means applicable and "-" means not applicable.
Table 4 Flange types and their application scope
Foreword i
Introduction iii
1 Scope
2 Normative references
3 Types and parameters
3.1 Nominal pressure
3.2 Nominal size
3.3 Outside diameter of steel pipe
3.4 Types and codes of flanges
3.5 Types and codes of sealing faces
3.6 Flange types and their application scope
4 Type and size of flange
4.1 Size of sealing face of flange
4.2 Type and size of flanges
5 Technical requirements
5.1 Material
5.2 Pressure-temperature rating
5.3 Dimensional tolerance
5.4 Joint sealing face
5.5 Fasteners and gaskets
5.6 Types and dimensions of welding ends
5.7 Machining and manufacturing
6 Tests
7 Inspection and acceptance
7.1 Inspection
7.2 Acceptance
8 Marking and labeling
8.1 Marking
8.2 Labeling
9 Supply requirements
Annex A (Informative) Order contract data of flange
Annex B (Informative) Method for determination of pressure-temperature ratings
Annex C (Informative) Regulations of ASME B16.5 on material selection and pressure-temperature ratings of steel pipe flanges
Annex D (Normative) Types and dimensions welding ends
Annex E (Informative) Reference mass of flanges
Annex F (Informative) Schedule number and steel pipe wall thickness
Bibliography
