Some standard content:
GB/T 9124--2000
This standard is a revised version of GB/T9125--1988 "Technical Conditions for Steel Pipe Flanges", and replaces (GB/T9125--1988 "Technical Conditions for Steel Pipe Flanges", GB/T9124--1988 "Butt Welding Ends of Steel Pipe Flanges" and (GB/T9131---1988 "Pressure and Temperature Grades for Steel Pipe Flanges"). This standard is based on international and foreign advanced standards such as IS07005-1:1992 "Metal Flanges Part 1: Steel Code". 1. Combined with domestic use, the original standard has been modified as follows: 1. The composition of the original standard has been greatly adjusted. The original three independent standards have been merged into one standard. "Steel Pipe Method" Pressure-Temperature Grade (Appendix A) is used as an appendix to the standard; "Steel Pipe Flange Welding End" (Appendix 13) is used as a suggestive appendix. 2 The contents of the original standard have been appropriately modified and supplemented. The technical terms and dimensional tolerances in the original standard have been appropriately modified, flange materials have been added, and flange manufacturing requirements have been supplemented. In addition, the "Steel Pipe Method Calculation Quality (Appendix C)" has been added and used as a recommended appendix; Appendix A "Bolt and Nut Materials for Flanges" in the original standard has been deleted because the content of this part cannot meet the use requirements. It is necessary to formulate a "Fasteners for Steel Pipe Flange Connections" standard that is compatible with the flange standard. 3 The formulation method of the "Pressure-Temperature Grade" in the original standard and the pressure-temperature parameter values of different materials The "pressure-temperature grade" of the original standard, which belongs to the European flange system, is selected by comparing with the European materials and selecting the corresponding pressure-temperature parameters; for the "pressure-temperature grade" of the American flange system, the pressure-temperature parameters of different materials are determined by calculation. The revised "flange pressure-temperature grade" compares Chinese materials with European materials and American materials and selects the pressure-temperature parameters of the corresponding materials specified in ISO7005-1. The technical content of this standard is basically consistent with ISO7005-1:1992; the technical level is equivalent to it. The writing format of this standard is different from that of IS0)7005-1:1992. The reason for adopting the former writing format is mainly The number is used for convenience and inheritance in the implementation of the standard.
This standard replaces GI3/T9124-1988GB/T9125-1988 and (G3/T9131-1988) from the date of implementation. This standard is under the jurisdiction of the National Technical Committee for Standardization of Pipeline Accessories. The drafting units of this standard are: Mechanical Science Research Institute, National Chemical Equipment Design Technology Center, Beijing Iron and Steel Design and Research Institute, Zhejiang Chaoda Valve Co., Ltd., Tianjin Jinding Pipeline Co., Ltd., Wuxi Petrochemical General Parts Factory, East China University of Science and Technology. The main drafters of this standard are: Li Junying, Ying Daoyan, Yu Jun, Chen Lin, Shu Zonghan, Qiu Xiaolai, Min Zhiqing, Li Renxing, Cai Renliang. This standard was first issued in 1988 and revised for the first time in 2000. 278
1 Scope
National Standard of the People's Republic of China
Steel pipe flanges
Technical conditions
Specification for steel pipe flangesGB/T 9124 -2000
Replaces GB/T 9124
GB/T 9125--. 1988
G13/T 9131 1988
This standard specifies the technical requirements for materials, dimensional tolerances, sealing surface surface roughness, testing, inspection and acceptance of steel pipe flanges. This standard applies to steel pipe flanges specified in GB/T9112~9123.4--2000. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. The versions shown at the time of publication of this standard are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB150-1998 Steel pressure vessels
CB/T193-1981 Ordinary thread diameter and pitch series (diameter 1~600mm) (B3/T152.41988 Countersunk holes for hexagonal bolts and hexagonal nuts for fasteners GB/1700-1988 Carbon structural steel
GB/T711-1988 High-quality carbon structural steel hot-rolled thick steel plates and wide steel strips GB/T3274-1988 Carbon structural steel and low-alloy structural steel, hot-rolled thick steel plates and steel strips GB3531- 1996 Low temperature pressure vessel Sichuan low alloy steel plate GB/T4237--1992 Stainless steel hot rolled steel plate GB6654--1996 Steel plate for pressure vessel
GB/T7306.1--2000 55° sealing pipe thread Part 1: Cylindrical internal thread and tapered external thread (cqVIS0) 7-1: 1994) GB/T7306.2---2000 55° sealing pipe thread Part 2: Tapered internal thread and tapered external thread (cVIS) 71: 1994) GB/T 9112-2000
Types and parameters of steel pipe flanges
GB/T 12229--1989
Technical conditions for carbon steel castings for general valves
GB/T 12230--1989
GB/T 12716—1991
GB/T 11976 --1994
Technical conditions for austenitic steel castings for general valves 60° tapered pipe thread
Seamless stainless steel pipes for fluid transportation
GB/T16253—1996Pressure steel castings
1B47262000Carbon steel and low alloy steel forgings for pressure vesselsCarbon steel and low alloy steel forgings for low-temperature pressure vesselsJB 4727.- 20001
JB4728-—2000
Stainless steel forgings for pressure vessels
JB/T7248-1994Technical conditions for low temperature steel castings for valvesHG20537·1992Austenitic stainless steel welded steel pipe3 Materials
3.1 The materials for steel pipe flanges with nominal pressure grades belonging to the European system shall comply with the provisions of Table 1; the materials for steel pipe flanges with nominal pressure grades belonging to the American system shall comply with the provisions of Table 2. The chemical composition, mechanical properties, operating temperature and other technical requirements of flange materials shall comply with the provisions of the relevant standards listed in Tables 1 and 2. 3.2 The grade and technical requirements of forgings (including forged and rolled parts) shall comply with the corresponding requirements of JB4726~4728. 3.2.1 For low carbon steel and austenitic stainless steel forgings for flanges with a nominal pressure of PN ≤ 2.0 MPa, Grade I forgings are allowed. 3.2.2 Forgings for flanges with a nominal pressure of PN ≤ 5.0 MPa shall meet the requirements of Grade I or above forgings, except for the provisions of 3.2.1 and 3.2.3.
3.2.3 For flange forgings that meet any of the following conditions, the requirements of Grade II forgings shall be met: a) Forgings for flanges with a nominal pressure of PN ≥ 10.0 MPa; b) Chromium-molybdenum steel forgings for flanges with a nominal pressure of PN ≥ 5.0 MPa; c) Forgings for flanges with a nominal pressure of PN = 2.5 MPa and Ferritic steel forgings for flanges with working temperature ≤ -20C 4 Pressure-temperature grade of flanges
The maximum non-impact working pressure of flanges at different working temperatures shall comply with the provisions of Appendix A (Appendix to the standard). 5 Dimensional tolerances of flanges
5.1 The dimensional tolerances of flanges shall comply with the provisions of Table 3. 5.2 The dimensional tolerances of the sealing surfaces of the ring joints shall comply with the provisions of Table 4. 280
GB/T9124
(!LGIN&HOI)
LOUINSOO
6IN81O0
9291 1/8
(16480
HO1N800
!NUW60
(16N813)
ILONST-0
6IN81-0
GB/T 9124 -~2000
926 J/
2OEI00
6222180
OVo9T/122
8521 /
2321 ST
1999 10
199960
(002/89)
Z21iN21100
92611/5
1L01IN81+D0
ZOWFI!N2O00
ZONZ1iN2100
021 J/g
qN0x0243809z
206140205
(H6IN84O)
(!6IN8HOD)
ZOFINZ000
01N610
OWS0-10S
flange thickness (
flange height H
weld end outer diameterΛ
flange Inner diameter B and
Welding ring inner diameter B1
Flange outer diameter D
Sealing surface true diameter d
called convex surface and sample
groove surface height| |tt||GB/T 9124 --- 2000
Table 3 Dimensional tolerances of flanges
All types of double-sided processing
(including blanket holes)
Butt welding, flat welding, threaded,
loose sleeve, socket welding flange
butt welding flange,
butt welding ring loose sleeve flange,
Side ring loose sleeve flange
Butt welding flange
Socket welding flange
Others except the above two
All types
All Types (PN is 0.25, 0.6,
1. 0, 1. 6, 2.5, 4. 0, 6.3, 10. 0 and 16. 0 MPa)
All types (PN is 2.0, 5.0,
11.0.15.0, 26.0 and 42.0MPa)
All types
Dimension range
18≤C≤50
DN300~DN600| |tt||DN200 ~~ DN600
SDN125
DN150--DN300
SDN125
DN150-- DN600
DN700~DN1 000||tt ||≥DN1 200
DN200DN500
DN600~DN1 200
DN1 400
SDN250
MUN300
All sizes||tt| |Tolerance or limit deviation
Concave and convex surface sum
Slot surface diameter
Bolt hole center circle diameter K
Chord distance between two adjacent bolt holes
Chordal distance of any two bolt holes
Bolt hole diameter L
Bolt hole center circle and processing density
Coaxiality tolerance of cover
Sealing surface and bolt bearing surface Angle
Ring groove depth E
Ring groove top width F
GB/T 9124—2000
Table 3 (End)
All types
All types
All types
All types
All types
All types
All types
Standard range
All sizes
All sizes
M10~M24
M27~M33
M36~M52
M10~M24||tt| |M27~M33
M36M52
≥M56
DN600~DN1 200
≥DN1 400
≥DN10
DN80~DN150| |tt||DN200～DN500
≥DN600
≥DN10
Table 4 Seal surface size tolerance of ring connection surface
Ring center circle diameter P||tt| |Ring groove angle 23°
Ring groove fillet Rmax
Sealing surface diameter d
6 flange connection sealing surface
Tolerance or limit deviation
6.1 The processed surface roughness of the flange sealing surface should comply with the requirements in Table 5. According to the negotiation between the supplier and the buyer, the user can also choose the surface roughness of the sealing surface as specified in Table 6, but it should be specified in the order contract. The minimum hardness value of the ring groove on the ring connection sealing surface should be 30HB higher than the maximum hardness value of the metal ring gasket used.
6.2 The sealing surface of the raised face flange is allowed to be chamfered at ×45°. 6.3 When using non-metallic soft gaskets, water lines are allowed to be processed on the sealing surface of the raised face flange, but this should be noted in the order contract. 285
Bolts for flange connections
GB/T9124-2000
Users should select bolt materials based on the pressure, temperature, material of the flange and the selected gasket to ensure Flange connections remain tight under expected operating conditions.
For bolts with a thread specification of small D or equal to M45, it is recommended to use the coarse thread series in GB/T193; for bolts with a thread specification greater than or equal to M48, it is recommended to use the fine thread series with the same pitch of 4mm in GB/T193 5. The surface roughness of the sealing surface when the requirements are not specified: dense surface type
full plane, raised surface,
concave and convex surface
full planebzxZ.net
(processing of dense texture Line, only for soft gasket) groove surface
ring connection surface
sealing surface code
FF, RF,
Table 6 Surface of sealing surface when ordering requirements Roughness gasket type
Non-metallic flat gasket
Flexible graphite composite gasket
PTFE coated gasket
Toothed combination gasket|| tt||wound gasket
metal covered gasket
metal ring gasket
8 flange neck
stainless steel
carbon steel, chromium steel
Stainless steel
Dense grain waterline ruler+.nim
Waterline pitch
Add J tool rounded corners
6.3, 12.5 (plus water line)
G.3, 12.5 (processing water line)
G.3, 12.5 (processing water line)
3.2, 6.3
8.1 flat neck For welding, butt welding, threaded, socket welding and loose tube flanges, the flange neck shall be cylindrical. A draft angle of not more than 7 on the outside of the flange neck is allowed.
8.2 The slope II type and dimensions of the welding of flange and steel pipe are shown in Appendix B (Appendix of Tips). 9 Machining of flanges
9.1 The bolt bearing surface of the flange shall be machined or strontium drilled, and the hole size shall be in accordance with the relevant provisions of GB/T152.4. The processed thickness should ensure that it meets the limit deviation requirements specified in Table 3. 9.2 The thread I requirements of the thread method should comply with the relevant provisions of GB/T7306.1, GB/T7306.2 and GB/T12716. 9.3 All bolt holes should be equally distributed on the diameter of the bolt hole center circle; for the integral method, The bolt holes should be arranged mid-span with the main axis or plumb line of the pipeline.
10 flange test
GB/T9124-2000
10.1 Pipe flange In principle, the hydraulic test of a single flange is not carried out. After the flange is installed on the pipeline or equipment, its hydraulic test pressure should not be greater than 1.5 times the maximum non-impact working pressure at 20C specified in Appendix A. 10.2 The hydraulic pressure test of the integral flange should comply with the relevant product standards. 11 Inspection and acceptance of flanges
11.1 Appearance inspection
11.1.1 The forging surface should be smooth and there should be no forging scars! Defects such as cracks. 11.1.2 The machined surface shall be free of burrs, harmful scratches and other defects that reduce the strength of the flange and the reliability of the connection. 11.1.3 The sealing surface of the ring connection surface flange should be inspected one by one. There should be no surface defects such as cracks, scratches or bruises caused by mechanical processing on the two sides of the groove.
11.2 The flange material shall comply with the relevant standards and shall have a factory inspection certificate. 11.3 The processing quality of the customs shall comply with the regulations of this technical condition. 11.4 After the flange is processed, anti-rust oil should be applied to its sealing surface to prevent scratches and impacts. 11.5 The non-destructive testing of the flange shall be determined through consultation between the user and the manufacturer. 11.6 The acceptance rules of the legal benefits shall be determined by negotiation between the user and the manufacturer. 12 Marking
Except for the integral flange, the following markings shall be made on the outer cylindrical surface of each flange (including the flange cover): a) the manufacturer's trademark;
b) the material mark;
c) the nominal pressure PN and the nominal diameter DN.
Note: The PN value is marked as a bar value.
A1 General
GB/T91242000
Appendix A
(Standard Appendix)
Pressure-temperature rating of steel pipe flanges
The pressure-temperature rating given in this appendix is applicable to flanges made of the materials specified in the table. The pressure-temperature ratings of various materials given in this appendix refer to the maximum non-shock working pressure (in gauge pressure) at the temperature indicated. For the pressure at intermediate temperatures, linear interpolation is allowed. A2 Nominal pressure level Pressure-temperature level of flanges belonging to the European system PN0.25, PN0.6, PN1.0, PN1.6, PN2.5, PN4.0, PN6.3, PN10.0 and PN16.0 MPa The pressure-temperature level of flanges is given in Table A1 to Table A9: These levels are only applicable to necked butt-welding flanges, necked slip-on flanges, necked threaded flanges, integral flanges and flange covers with nominal diameters of DN10 to DN600. For plate slip-on flanges, slip-on ring plate loose flanges, butt-welding ring plate loose flanges and flanged ring plate loose flanges, as well as necked butt-welding flanges, necked slip-on flanges, integral flanges and flange covers with nominal diameters above IN600, the pressure-temperature level is determined by the user. The flange material group numbers listed in Table A1 to Table A9 shall comply with the provisions of Table 1 of this standard. The maximum non-impact working pressure value of ferritic steel 100C in the table can be used up to 120C, and the maximum non-impact working pressure value of austenitic stainless steel 20℃ can be used up to 50C. A3 The pressure-temperature grades of flanges with nominal pressure grades belonging to the American system PN2.0, PN5.0, PN11.0, PN15.0, PN26.0 and PN42.0MPa The pressure-temperature grades of flanges are given in Table A10~Table A15.
The flange material group numbers listed in Table A10~Table A15 are in accordance with the provisions of Table 2 of this standard. When other materials are used, the flange pressure-temperature grade can be converted according to Table A10~Table A15 based on the allowable stress of the material, but it shall not be lower than the value listed in Table A16 A4 Flange connection grade
If the two flanges connected have different pressure-temperature grade values, the grade of the flange connection at any temperature shall not exceed the lower of the two flange grades at the corresponding temperature. A5 Instructions for Use
A5.1 The operating temperature shown in the corresponding pressure grade is considered to be the temperature of the medium contained. If the pressure grade is selected for a temperature different from the medium contained, it shall be the responsibility of the user, but shall comply with the requirements of any applicable specifications or regulations. A5.2 When the grades in this standard are used for flange connections, the risk of leakage caused by the forces and moments generated in the pipe connection should be considered. Therefore, it is recommended not to use socket welding and threading when the temperature is higher than 260°C under rapid temperature changes and thermal cycling conditions. A5.3 When the operating temperature is within the creep temperature range of the material, the gradual relaxation of the flange connection will continuously reduce the bolt load and affect the tightness of the connection. Therefore, it is necessary to tighten the bolts regularly to prevent leakage. A5.4 When the operating temperature of PN2.0MPa flange exceeds 200°C and the operating temperature of PN5.0MPa flange exceeds 400°C, the flange should be protected from rapid temperature changes and external loads, otherwise the sealing performance of the flange may be reduced. 288
Material Group Number
GB/T 9124-- 2000
PNO.25MPaFlange Maximum Non-Shock Working PressureWorking Temperature, C
0. 1750. 15
0.150.1250.088
0.250.2450.2380.225
0.2230.201
0.1750.1380.113
0. 2380. 2280. 2230. 2180. 2050. 185|0. 155 0. 123 [0. 0950.25
0.250.2280.2230.218
0. 163/0. 1520. 1410. 1340. 1290.234
0. 2120. 191
0. 1740. 161 | | tt | | 0.1430.139 | 250.2340.2120.197|0.1860.1730.1670.16
Note: When the working temperature is higher than the table temperature, there is no exact value. 0.124
Table A2PNO.6MPa Flange Maximum Non-Shock Working Pressure T Operating Temperature, C
Material Group Number
0.600. 60
0. 600. 60
0. 610. 56
0.1380.125
0. 546 0. 5340, 5220. 492i0. 4110. 3720. 294j0. 2280.57
0.600.5460.5340. 5220.48
Note: When the working temperature is higher than the humidity listed in the table, there is no exact value 0.4When the operating temperature of the 0MPa flange exceeds 400C, the flange should be prevented from undergoing rapid temperature changes and external loads, otherwise the sealing performance of the flange may be reduced. 288
Material group number
GB/T 9124-- 2000
PNO.25MPa flange maximum non-impact working pressure and working temperature, C
0. 1750. 15
0.150.1250.088
0.250.2450.2380.225
0.2230.201
0.1750.1380.113
0. 2380. 2280. 2230. 2180. 2050 . 185|0. 155 0. 123 [0. 0950.25
0.250.2280.2230.218
0. 163/0. 1520. 1410. 1340. 1290.234
0. 2120. 191 | | tt | 21
0. 250.2340.2120.197|0.1860.1730.1670.16
Note: When the operating temperature is higher than the listed temperature, there is a lack of exact values. 0.124
Table A2PNO.6MPa flange maximum non-impact working pressure T operating temperature, C
Material group number
0.600. 60
0. 600. 60|| TT || 0.610. 56 || TT || 0.1380.125 || TT || 0.546 0.5340, 5220.492i0. 4110. 3720. 294J0. 2280.57 || TT || 0.600.5460.5340. 5220.48 | |tt||Note: When the working temperature is high and the humidity listed in the table is high, the exact value 0.4 is lacking.When the operating temperature of the 0MPa flange exceeds 400C, the flange should be prevented from undergoing rapid temperature changes and external loads, otherwise the sealing performance of the flange may be reduced. 288
Material group number
GB/T 9124-- 2000
PNO.25MPa flange maximum non-impact working pressure and working temperature, C
0. 1750. 15
0.150.1250.088
0.250.2450.2380.225
0.2230.201
0.1750.1380.113
0. 2380. 2280. 2230. 2180. 2050 . 185|0. 155 0. 123 [0. 0950.25
0.250.2280.2230.218
0. 163/0. 1520. 1410. 1340. 1290.234
0. 2120. 191 | | tt | 21
0. 250.2340.2120.197|0.1860.1730.1670.16
Note: When the operating temperature is higher than the listed temperature, there is a lack of exact values. 0.124
Table A2PNO.6MPa flange maximum non-impact working pressure T operating temperature, C
Material group number
0.600. 60
0. 600. 60|| TT || 0.610. 56 || TT || 0.1380.125 || TT || 0.546 0.5340, 5220.492i0. 4110. 3720. 294J0. 2280.57 || TT || 0.600.5460.5340. 5220.48 | |tt||Note: When the working temperature is high and the humidity listed in the table is high, the exact value 0.4 is lacking.
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