Some standard content:
National Standard of the People's Republic of China
Steel Spherical Tanks
Steel Spherical Tanks
GB12337-98
This standard is a revision of GB12337-90 according to the arrangement of the "National Standard Promotion Project Plan for the Formulation and Revision of the State Technical Supervision Bureau in 1993". This standard is a comprehensive national standard that includes the design calculation of spherical shells, pillars, tie rods, etc., material selection requirements, structural inspection regulations, and the manufacture, welding, inspection and acceptance of spherical tanks (hereinafter referred to as spherical tanks).
This standard is based on the implemented GB1233790 "Steel Spherical Tanks", after investigation and analysis and experimental verification, combined with successful use experience, and absorbs the advanced content of similar international standards, enriched, improved and improved, and formulated according to the principle of ensuring the safe use of spherical tanks. In addition to complying with the provisions of this standard, the design, manufacture, welding, inspection and acceptance of spherical tanks shall also comply with the relevant provisions of GB 150.
Compared with GB12337-90, this standard mainly includes the following modifications:
- Modify the relevant contents according to the revision of GB150. 一 Add direct connection structure type and U-shaped structure type to the connection between the pillar and the spherical shell.
- Modify the content of pillar stability verification. Add the manufacturing and welding requirements of high-strength and high-toughness steel. 一 Supplement the content related to automatic welding.
The calculation examples are cancelled from the main text and compiled in the standard interpretation. Appendix A and Appendix B of this standard are both standard appendices. Appendix C of this standard is a prompt appendix. From the date of implementation, this standard will replace GB 12337-90 at the same time.
This standard is proposed and managed by the National Technical Committee for Standardization of Pressure Vessels.
This standard was drafted by the Lanzhou Petroleum Machinery Research Institute of the Ministry of Machinery Industry. The participating units include: Chemical Spherical Tank Joint Engineering Company of the Ministry of Chemical Industry, Dalian Boiler and Pressure Vessel Inspection Institute of the Ministry of Labor, Beijing Petrochemical Engineering Company of Sinopec Corporation, Lanzhou Petrochemical Design Institute of Sinopec Corporation, and Lanzhou Petrochemical Machinery General Plant. The main drafters of this standard are: Liu Fulu, Yao Yujing, Liu Yien, Liu Hongbo, Zhang Jie, Yu Minmin, and Sun Jie. The working units and personnel participating in the preparation of this standard are: Planning Institute of Sinopec Corporation: Shou Binan, Huang Xiurong, Gu Zhenming, Wang Weiguo, and Ye Qianhui.
China General Petrochemical Machinery Engineering Corporation: Zhang Zhongkao. Construction Coordination Department of the Ministry of Chemical Industry: Liang Zhixun.
Occupational Safety and Health and Boiler and Pressure Vessel Supervision Bureau of the Ministry of Labor: 1664
Song Hongming and Zhang Jianrong.
Beijing Petrochemical Engineering Company of Sinopec: Li Shiyu. This standard was first issued on May 25, 1990 and revised for the first time in March 1998.
This standard shall be interpreted by the National Technical Committee for Standardization of Pressure Vessels.
1 Scope
This standard specifies the requirements for the design, manufacture, welding, inspection and acceptance of spherical storage tanks made of carbon steel and low alloy steel (hereinafter referred to as "spherical tanks").
1.1 This standard applies to orange-shaped or mixed-type spherical tanks supported by pillars with a design pressure not exceeding 4MPa. 1.2 The design temperature range applicable to this standard is determined according to the allowable service temperature of the steel.
1.3 This standard does not apply to the following spherical cores:
a) Spherical tanks subjected to nuclear radiation;
b) Spherical tanks subjected to relative motion (such as vehicle-mounted or ship-mounted); c) Spherical tanks with a nominal volume of less than 50m2; d) Spherical tanks requiring scrap labor analysis;
e) Spherical tanks with double-shell structures.
2 Referenced Standards
The following standards contain provisions that constitute the provisions of this standard through reference in this standard. When this standard is released, the versions shown 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
GB/T228—1987 Metal tensile test method GB/T 229—1994
Metal Charpy notch impact test method
GB/T 232—1988
8 Metal bending test method
Technical conditions for high-quality carbon structural steel
GB/T 699-~1988
GB/T 700—1988
Carbon structural steel
GB/T984—-1985 Overlay welding electrodes
GB/T985—1988Basic shapes and dimensions of weld grooves for gas welding, manual arc welding and gas shielded welding
GB/T GB 986--1988
Basic shapes and dimensions of buried arc welding weld grooves
GB 3077--1988 Technical conditions for alloy structural steels GB 3274-1988 Hot-rolled thick steel plates and strips of carbon structural steels and low-alloy structural steels
GB 3531-1996 Low-alloy steel plates for cryogenic pressure vessels
GB/T 3965-1995 Determination method for diffusible hydrogen in deposited metal
GB/T 4842--1995
GB/T S117—1995
GB/T 5118—1995
GB/T 5293—1985
GB/R 6052—1993
GB 6479—1986
GB 6654—1996
Carbon steel welding rod
Low alloy steel welding rod
Carbon turbulent steel for submerged arc welding
Industrial liquid carbon dioxide
High pressure seamless steel for fertilizer equipment
Steel plate for pressure vessel
GB/T 8110—1995
Carbon steel and low alloy steel welding wire for gas shielded welding
GB/T 8162---1987
GB/T 8163—1987
Seamless steel pipe for structure
Seamless steel pipe for conveying fluid
Seamless steel pipe for petroleum cracking
GB 9948—1988
Carbon steel flux-cored welding wire
GB/T 10045—1988
GB/T 12470—1990↑
Flux for submerged arc welding of low alloy steel
GB/T14957--1994Steel wire for fusion welding
GB/T 14958--1994
Steel wire for gas shielded welding
Type and base of steel spherical storage tanks
GB/T 17261--1998
Basic parameters
GBJ 9—87
Code for loads on building structures
JB2536—80Painting, packaging and transportation of pressure vesselsJB 4707—92
JB 4708—92
Equal length studs
Welding procedure assessment for steel pressure vessels
JB/T 4709—92
JB 4726—94
Welding procedure for steel pressure vessels
Carbon steel and low alloy steel for pressure vessels
JB4727—94Carbon steel and low alloy steel forgings for low-temperature pressure vessels
Non-destructive testing of pressure vessels
JB4730—94
The design, manufacture, welding, inspection and acceptance of spherical tanks shall comply with the provisions of GB150 in addition to complying with the provisions of this standard.
3.1 Scope of ball and dish
The scope of the spherical tank governed by this standard refers to the spherical shell and its integral parts, and is defined within the following scope: 3.1.1 Connection between spherical tank and external pipeline
a) The first circumferential joint bevel end face of welding connection; b) The first threaded joint end face of threaded connection; ) The first flange sealing surface of flange connection. 3.1.2 Pressure-bearing head, flat cover and fasteners of spherical tank pipe and manhole:
3.1.3 Welded joints between non-pressure components and the inner and outer surfaces of the spherical shell, and components other than joints, such as pillars, tie rods and bottom plates, shall also comply with the relevant provisions of this standard.
3.1.4 Overpressure relief device directly connected to the spherical tank. Overpressure relief device shall comply with the provisions of Appendix B "Overpressure Relief Device" of GB150. Instruments and other accessories connected to the spherical tank shall comply with the provisions of relevant standards.
3.2 Qualifications and responsibilities
3.2.1 The design, manufacturing and welding units of spherical tanks should have a sound quality management system. The design unit should hold the approval letter for the design unit of pressure vessels (including spherical tanks), and the manufacturing and welding units should hold the manufacturing license for pressure vessels (including spherical tanks). 3.2.2 The design, manufacture and welding of spherical tanks must be subject to the supervision of the boiler and pressure vessel safety supervision agency of the quality and technical supervision department.
3.2.3 Responsibilities of the design unit
3.2.3.1 The design unit shall be responsible for the correctness and completeness of the design documents.
3.2.3.2 The design documents of the spherical tank shall at least include the design calculation book and design drawings.
3.2.3.3 The technical documents of the design drawings shall state the name of the medium contained, its composition, applicable national standards (industry standards), main process parameters, special requirements, etc. 3.2.3.4 The general design drawing of the spherical tank shall be stamped with the approval mark of the pressure vessel design unit.
3.2.4 Responsibilities of the manufacturing and welding units
3.2.4.1 The manufacturing and welding units shall carry out manufacturing and construction in accordance with the design drawings. If the original design needs to be changed, the approval of the original design unit shall be obtained.
3.2.4.2 The manufacturing unit shall provide the following technical documents for each spherical tank:
a) Factory acceptance certificate of spherical shell plate and its welded parts; b) Material quality certificate;
c) Welding record of spherical shell plate and manhole, connecting pipe and support; 1665
d) Non-destructive testing report;
e) Spherical shell layout drawing:
If necessary, the following technical documents shall also be provided: f) Material substitution approval document:
g) Heat treatment report of welded parts welded with spherical shell plate; h) Mechanical and bending properties report of spherical shell plate hot pressing process test plate;
i) Re-inspection report of spherical shell plate material:
i) Mechanical and bending properties test report of electrode plate welding joint.
3.2.4.3 The welding unit shall provide the following technical documents for each spherical tank:
a) original design drawings and completion drawings;
b) spherical tank completion acceptance certificate. The certificate shall at least include the following contents:
Quality certificate of spherical shell plate and its welded parts; spherical tank foundation inspection record;
spherical tank welding record (with weld layout drawing); welding material quality certificate or re-inspection report; product welding test plate test report;
welding joint non-destructive testing report;
welding joint repair record:
spherical tank post-welding overall heat treatment report:
spherical tank geometric size inspection record:
spherical tank support inspection record;
spherical tank pressure test report;
foundation settlement observation record;
spherical tank air tightness test report.
Upper Xinjiang belt
Chizunxiong
Xia Wenzan
Safety accessories
Ren platform
Lower pole pipe · person
Figure 1 Names of various parts of the spherical tank
3.3 Names of various parts of the spherical tank
The names of various parts of the spherical tank and the pillars are shown in Figures 1 and 2. Cover plate
Upper pillar
Upper ear
Fireproof layer
Lower pillar
Settlement measurement plate
Vent
Floor
Lower ear
Increase foot screw inspection
3.4.1 Pressure
Figure 2 Names of various parts of the pillar
Unless otherwise specified, pressure refers to gauge pressure. 3.4.2 Working pressure
Working pressure refers to the maximum pressure that may be reached at the top of the spherical tank under normal working conditions.
3.4.3 Design pressure
Design pressure refers to the maximum pressure set at the top of the spherical tank, which is used as the design load condition together with the corresponding design temperature, and its value shall not be lower than the working pressure.
When an overpressure relief device is installed on the spherical tank, the design pressure shall be determined in accordance with the provisions of Appendix B "Overpressure Relief Device" of GB150. For spherical tanks containing liquefied gas, within the specified filling factor range, the design pressure shall be determined based on the maximum metal temperature that may be reached under working conditions.
3.4.4 Calculation pressure
Calculation pressure refers to the pressure used to determine the thickness of each belt of the spherical shell or the thickness of the pressure-bearing component at the corresponding design temperature, including the static pressure of the liquid column.
3.4.5 Test pressure
Test pressure refers to the pressure at the top of the spherical tank during the pressure test. 3.4.6 Maximum Allowable Working Pressure
The maximum allowable working pressure refers to the maximum gauge pressure allowed to be borne by the top of the spherical tank at the design temperature. This pressure is calculated based on the effective thickness of the spherical shell, and the minimum value is taken directly. 3.4.7 Design Temperature
The design temperature refers to the metal temperature of the pressure component set for the spherical tank under normal working conditions (the average temperature along the metal cross section of the component). The design temperature and the design pressure are used as the design load conditions.
The design temperature shall not be lower than the highest temperature that the component metal may reach under working conditions. For metal temperatures below 0℃, the design temperature shall not be higher than the lowest temperature that the component metal may reach.
The design temperature of the low-temperature ball shall be determined in accordance with Appendix A (Appendix to the standard).
The design temperature marked on the nameplate shall be the highest or lowest value of the spherical shell design temperature.
The metal temperature of the component can be obtained by heat transfer calculation, or measured on a similar spherical tank that has been used, or determined according to the internal medium temperature.
3.4.8 Test temperature
The test temperature refers to the metal temperature of the spherical shell during the pressure test. 3.4.9 Thickness
3.4.9.1 Calculated thickness
Calculated thickness refers to the thickness calculated according to the formula. When necessary, the thickness required for other loads should also be taken into account (see 3.5.2). 3.4.9.2 Design thickness
Design thickness refers to the sum of calculated thickness and corrosion allowance. 3.4.9.3 Nominal thickness
Nominal thickness refers to the design thickness plus the negative deviation of steel thickness, rounded up to the thickness of the standard steel specification. That is, the thickness marked on the drawing.
Note: Nominal thickness does not include processing allowance. 3.4.9.4 Effective thickness
Effective thickness refers to the nominal thickness minus the corrosion allowance and the negative deviation of steel thickness.
3.5 General provisions for design
3.5.1 For spherical tanks with different working conditions, the design should be based on the most demanding working condition, and the pressure and temperature values of each working condition should be indicated in the drawings or relevant technical documents.
3.5.2 Loads
The following loads should be considered during design:
a) pressure;
6) static pressure of liquid;
c) deadweight of the spherical tank (including internal parts) and the gravity load of the material inside under normal working conditions or pressure test conditions;
d) gravity load of auxiliary equipment and insulation materials, pipelines, pillars, tie rods, ladders, platforms, etc.;
When necessary, the following loads should also be considered:
f) reaction force of the pillar;
g) force of connecting pipelines and other components;
h) force caused by temperature gradient or thermal expansion;
i) impact load including sharp pressure fluctuations;
i) impact reaction force, such as the reaction force caused by fluid impact.
3.5.3 Thickness AdditionbZxz.net
Thickness addition is determined according to formula (1):
C = C + C2
Wherein: C-
Thickness Addition, mm;
Ci——Negative deviation of steel thickness, according to 3.5.3.1, mm; Cz——Corrosion allowance, according to 3.5.3.2, mm3.5.3.1 Negative deviation of steel thickness
Negative deviation of steel plate or steel pipe thickness shall be in accordance with the provisions of steel standards. When the negative deviation of steel thickness is not greater than 0.25mm and does not exceed 6% of the nominal thickness, the negative deviation can be ignored. 3.5.3.2 Corrosion allowance
In order to prevent the thickness of the spherical tank components from being weakened and thinned due to corrosion and mechanical wear, the corrosion allowance should be considered. The specific provisions are as follows:
a) For components with corrosion or wear, the corrosion allowance should be determined based on the expected life of the spherical tank and the corrosion rate of the material on the metal material:
b) When the corrosion degree of each component of the spherical tank is different, different corrosion allowances can be used;
c) The corrosion allowance shall not be less than 1mmo
3.6 Allowable stress
3.6.1 The allowable stress of the materials used in this standard shall be selected according to Chapter 4. The basis for determining the allowable stress is: steel (except bolt materials) according to Table 1, bolt materials according to Table 2.
The allowable stress is the minimum value among the following
values, MPa
ob/3.0 0./1.6 c:/1.6
Carbon steel, low alloy steel
-The lower limit of standard tensile strength of steel, MPa; in the table: o
-Standard yield point of steel at room temperature, MPa;
The yield point of steel at design temperature, MPaTable 2
Material Bolt diameter, mmAllowable stress in heat treatment state, MPaa2.7
Carbon steel
Low alloy steel
≤M22
M24~M48
M24-M48
Hot rolling, normalizing
3.6.2When the design temperature is lower than 20℃, take the allowable stress at 20℃.
3.7Welding joint coefficient
The welding joint coefficient of double-sided full penetration butt joint shall be selected according to the following provisions:
100% non-destructive testing
Local non-destructive testing
3.8 Pressure test
The spherical tank shall be subjected to pressure test after manufacture. The type, requirements and test pressure value of the pressure test shall be indicated on the drawing. The pressure test can be carried out by hydraulic pressure or pneumatic pressure. Generally, hydraulic pressure is used. The test liquid shall be in accordance with the requirements of 8.10.4. The spherical tank for pneumatic pressure test must meet the requirements of 8.10.5.
3.8.1 Test pressure
The minimum value of the test pressure shall be in accordance with the following provisions, and the upper limit of the test pressure shall meet the limits of stress check in 3.8.2. Hydraulic test
Air pressure test
Where: PT
pr = 1.25p
Pr = 1.15*
Test pressure, MPa;
Design pressure, MPa;
Allowable stress of spherical shell material at test temperature, MPa;
[]t——Allowable stress of spherical shell material at design temperature, MPa.
Note: When the maximum allowable working pressure is specified on the ball nameplate, the maximum allowable working pressure shall be used in place of the design pressure in the formula. 1668
3.8.2 Stress check before pressure test.
Before the pressure test, the spherical shell stress should be checked according to formula (4): OT
where: aT
PT(D, + 8)
Stress of the spherical shell under the test pressure, MPa;
Test pressure, MPa
Inner diameter of the spherical shell, mm;
8. —Effective thickness of the spherical shell, mm.
αT satisfies the following conditions:
During the hydraulic test, 01≤0.9g,
During the air pressure test, a≤0.8g,
where: s
Yield point of the spherical shell material at the test temperature, MPa;
—Welding joint coefficient of the spherical shell.
3.9 Air tightness test
If required by the drawing, the ball should also be subjected to an air tightness test. The airtightness test shall be carried out after the pressure test is qualified. 3.9.1 The spherical tanks containing the following materials shall be subjected to airtightness test: a) materials with extremely or highly hazardous toxicity; b) flammable compressed gas or liquefied gas. Note: The classification of toxicity and the classification of flammable media shall be in accordance with the provisions of the "Regulations on Safety Technical Supervision of Pressure Vessels" (the same below). 3.9.2 The airtightness test pressure shall be determined according to formula (5). PT = 1.0p
Where: pr-
test pressure, MPa;
p---—design pressure, MPa.
4 Materials
4.1 Basic requirements
4.1.1 The steel used for spherical joint pressure components shall comply with the provisions of this chapter. The steel used for non-pressure components, when welded with pressure components, shall also be steel with good welding performance.
4.1.2 The use of steel materials with other steel grades other than those specified in this chapter shall also comply with the relevant provisions of Appendix A "Supplementary Provisions for Materials" of GB150.
4.1.3 The steel used for the pressure-bearing components of spherical tanks shall be smelted by open-hearth furnaces, electric furnaces or oxygen converters. The technical requirements of steel materials shall comply with the relevant national standards, industry standards or relevant technical documents. 4.1.4 The steel used for spherical tanks shall be accompanied by the steel quality certificate of the steel production unit. The manufacturing unit shall inspect and accept the steel materials according to the quality certificate and re-inspect them if necessary. If there is no steel quality certificate (original) from the steel production unit, the provisions of the "Regulations on Safety Technical Supervision of Pressure Vessels" shall be followed.
4.1.5 The selection of steel for spherical tanks shall take into account the use conditions of the spherical tanks (such as design temperature, design pressure, material properties, etc.), the welding performance of the materials, the manufacturing process and assembly welding requirements of the spherical tanks, and economic rationality.
4.1.6 When the design temperature of the spherical tank is lower than or equal to -20℃, the steel shall also comply with the provisions of Appendix A.
4.1.7 When there are special requirements for steel (such as special refining methods, higher impact energy indicators, higher non-destructive testing requirements, increased mechanical property inspection rates, and consideration of the requirements of the medium for steel corrosion, etc.), the design unit shall indicate this in the drawings or corresponding technical documents.
4.1.8 When the design temperature is higher than 200°C, the allowable stress value shall be in accordance with the provisions of (GB150.
4.2.1 The standard, service state and allowable stress of steel plates shall be in accordance with the provisions of Table 3.
Steel plates that meet the following conditions shall be used in the normalized state4.2.2
:
15MnVR
15MnVNR
07MnCr
16MnDR
07MnNiCr
09Mn2VDR
Steel plate standard
GB 6654
GB6654
GB 6654
GB6654
GB3531
GB3531
Use status
Hot rolling, normalizing
Hot rolling, normalizing
Normalizing,
Normalizing and tempering
Thickness mm
>16～36
>36 ~60
>60～100
>16 ~36
>36 ~60
>60～100
>100～120
>16 ~36
>36~60
>16 ～36
>36 ～60
16 ~ 50
>16～36
>36～60
>60～100
>16~36
a) Steel plates for spherical shells
20R and 16MnR with a thickness greater than 30mm;
15MnVR with a thickness greater than 16mm;
15MnVNR with any thickness;
b) 20R and 16MnR with a thickness greater than 50mm for other pressure-bearing components (flanges, flat covers, etc.).
4.2.3 Steel plates for spherical shells that meet the following conditions shall be subjected to tensile and Charpy (V-notch) room temperature or low overflow impact tests one by one a) Steel plates supplied in quenched and tempered state;
b) Steel plates with a thickness greater than 60mm.
4.2.4 For the following steel plates used for spherical shells, when the design temperature and thickness of the spherical tank meet the following conditions, one steel plate from each batch shall be subjected to a composite ratio (V-notch) low-temperature impact test. The test temperature is the design temperature of the spherical tank or as specified in the drawing, and the sample sampling direction is horizontal.
a) When the design temperature is lower than 0℃, 20R with a thickness greater than 25mm, 16MnR, 15MnVR and 15MnVNR with a thickness greater than 38mm.
Normal temperature strength index
Note: The allowable stress at the intermediate temperature can be obtained by interpolation according to the stress value in this table. 1) The technical requirements of this steel plate can be found in Appendix A "Supplementary Provisions for Materials" of GB150. a
Allowable stress at the following temperatures (℃)
MPa
b) When the design temperature is lower than -10℃, 20R with a thickness greater than 12mm, 16MnR, 15MnVR and 15MnVNR with a thickness greater than 20mm.
The index of low-temperature impact energy shall be in accordance with the corresponding provisions of Appendix A according to the lower limit of tensile strength of the steel plate standard.
4.2.5 When the design temperature of the ball is lower than or equal to -20C, the service state and the minimum impact test temperature of the steel plate shall comply with the provisions of Table 4. Table 4
07MnCr
16MnDR
07MnNiCr
(9Mn2VDR
Use status
Normalizing,
Normalizing and tempering
Thickness,
>36 ~ 100
Steel pipe standard
GB/T 8163
GB9948
GB 6479
GB6479
GB6479
Minimum impact test temperature,
Wall thickness mm
4.2.6 All steel plates for spherical shells that meet the following conditions shall be subjected to ultrasonic testing one by one:
a) 20R and 16MnR steel plates with a thickness greater than 30 mm; b) 15MnVR and 15MnVNR steel plates with a thickness greater than 25 mm:
c) 16MnDR and 09Mm2VDR steel plates with a thickness greater than 20 mm;
d) Steel plates supplied in the quenched and tempered state;
e) Main lower pole plates and equatorial plates connected to the pillars. Ultrasonic testing of steel plates shall be in accordance with the provisions of JB4730. The quality grade of steel plates supplied in the hot-rolled and normalized state shall not be lower than Grade III, and the quality grade of steel plates supplied in the quenched and tempered state shall not be lower than Grade II. 4.3 Steel
The standards and allowable stresses of steel pipes shall be in accordance with the provisions of Table 5. 15MnV, 09Mn2VD and 09MnD steel pipes should be used in normalized state.
Normal temperature strength index
Note: The allowable stress value at the intermediate temperature can be obtained by the internal circulation method according to the stress value in this table 1) The technical requirements of this steel pipe can be found in Appendix A "Supplementary provisions for materials" of GB 150 4.3.3 When the design temperature of the spherical tank is lower than or equal to -20C, the use status and minimum impact test temperature of the steel pipe shall comply with the provisions of Table 6.
Use state
Wall thickness, mm
Minimum impact test
Test temperature,
Allowable stress at the following temperature (death), MPa
Use state
Wall thickness, mm
Minimum impact test
Test temperature, ℃
For steel pipes with small-size impact specimens of 5mm×10mm×55mm that cannot be prepared due to size limitations, impact tests are exempted. The minimum design temperature of steel pipes of various steel grades shall comply with the provisions of Appendix A. 4.4 Forgings
The standards and allowable stresses of forgings shall comply with the provisions of Table 7. Steel
20MnMo
20MnMoD
08MnNiCrMoVD
Forging standard
JB4726
JB4726
JB4727
JB4727
JB4727
Nominal thickness mm
>300~500
>500～700
>300 ～500
>500 ～700
Normal temperature strength index
09Mn2VD
JB4727
Note: The allowable stress value at the intermediate temperature can be obtained by interpolation according to the stress value in this table. The forging grade shall be determined by the design unit and noted in the drawing (with the grade symbol attached after the steel number, such as 16MnⅡ). The forging grade of manhole forgings shall not be lower than Grade Ⅲ. Steel grade
09Mn2VD
20MnMoD
08MnNiCrMoVD
Heat treatment state
Normalizing and tempering, quenching and tempering
Normalizing and tempering, quenching and tempering
4.5 Studs and nuts
Standards, service conditions and allowable stresses of stud steels are as follows:
Q235-A
40MnVB
30CrMoA
35CrMoA
Steel standards
GB/T 700
GB/T 699
GB/T 3077
GB/T 3077
GB/T 3077
GB/T 3077
GB/T 3077
Use status
Stud specification
≤M20
≤M22
M24 ~M27
≤M22
≤M22
M24~M36
M24~M36
≤M22
M24~M48
M52~M56
≤M22
M24~M48
M52~M80
M85~M105
M52-M140
Allowable stress at the following temperatures (℃)
, MPa
When the design temperature of the spherical tank is lower than or equal to -20℃, the heat treatment state and minimum impact test temperature of the forging shall be in accordance with the provisions of Table 8.
Nominal thickness, mm
≤200
≥>200～300
>500～700
As specified in Table 9.
Normal temperature strength index
40CrNiMoA
GB/T 3077
Note: The allowable stress value at the intermediate temperature can be obtained by interpolation according to the stress value in this table MPa
Minimum impact test temperature, C
Allowable stress at the following temperature (℃), MPa
4.5.2 Mechanical property test is carried out on rough pieces of low alloy steel studs after quenching and tempering heat treatment.
4.5.2.1 Rough pieces of studs with the same steel grade, the same furnace number, the same cross-sectional size, the same heat treatment system and put into production at the same time are a batch, and one piece is taken from each batch for testing.
4.5.2.2 The sampling direction of the specimen is longitudinal. For a rough specimen with a diameter of no more than 40 mm, the longitudinal axis of the specimen shall be located at the center of the rough specimen; for a rough specimen with a diameter of more than 40 mm, the longitudinal axis of the specimen shall be located at 1 point of the rough specimen radius. The distance between the specimen and the end of the rough specimen shall not be less than the diameter of the rough specimen, but the head (or clamping part) of the tensile specimen is not subject to this restriction.
40MnVB
30CrMoA
35CrMoA
Take one tensile specimen from each rough piece, and the impact test tempering temperature
≥550
≥550
≥550
≥600
≥560
40CrNiMoA
≥520
≤M22
M24~M36
≤M22
M24~M36
≤M22
M24 M36
≤M22
M24~M56
M24~M80
M85~M105
M52~M140
Three samples. The tensile test method shall comply with the provisions of GB/T228. The impact test method shall comply with the provisions of GB/T 229. The test results shall comply with the provisions of Table 10. The specified value of the impact energy in the table is the average value of the test results of three samples. It is allowed that the test result of one sample is less than the specified value, but it shall not be less than 70% of the specified value. For low-alloy steel studs with steel grades and specifications that meet the JB4707 standard, their mechanical properties can be accepted according to this standard.
4.5.2.4 If the tensile test results are unqualified, two more tensile specimens shall be taken from the same rough piece for re-testing to measure all three properties. As long as one of the data in the test results does not comply with the provisions of Table 10, the rough piece shall be judged as unqualified. Table 10
≥805
≥765
≥805
≥700
≥660
≥930
4.5.2.5 If the impact test result is unqualified, three more impact specimens shall be taken from the same rough piece for re-testing. The average impact energy of the six specimens in the two groups before and after shall not be less than the specified value. It is allowed that the impact energy of two specimens is less than the specified value, but only one of them is less than 70% of the specified value. Otherwise, the rough piece shall be judged as unqualified.
4.5.2.6 The whole batch of rough pieces judged as unqualified may be re-heat treated, and then re-sampled for tensile and impact tests according to the above procedures.
30CrMoA
30CrMoA
40CrNiMoA
Specifications, mm
M60~M80
M52 ~M80
M85~M140
0. (00.2)
≥635
≥735
≥685
≥635
≥550
≥735
For low alloy steel studs, when the design temperature is lower than or equal to ~20℃, a low temperature impact test at the design temperature shall be carried out. The steel grade and impact test requirements for low temperature studs shall be in accordance with the provisions of Table 11.
4.5.4 The nut steel used in combination with the stud steel can be selected according to Table 12. The designer can also select other nut steels with experience in use. The tempering temperature of the nut steel used in the quenched and tempered state should be higher than the tempering temperature of the stud steel used in combination. Table 11
Minimum impact test temperature, C
Stud steel grade
Q235-A
40MnVB
30CrMoA
35CrMoA
40CrNiMoA
Nut steel grade
Q215-A, Q235-A
Q235-A
35,40Mn,45
35.40Mn,45
35,40Mn,45
30CrMoA
40Mn，45
35CrMoA, 35CrMoA
30CrMoA, 40CrNiMoA
Welding materials
4.6.1 Welding rod
Steel for nuts
Steel standards
GB/T700
GB/T700
GB/T 699
GB/T 699
GB/T 699
GB/T 699
GB/T 3077
GB/T 699
GB/T 3077
GB/T 3077
GB/T 3077
4.6.1.1 Welding rods shall have a quality certificate. The quality certificate shall include the chemical composition, mechanical properties, diffusible hydrogen content, etc. of the molten metal. All indicators shall comply with the relevant provisions of GB/T5117, GB/T5118, GB/T984 and other standards. 4.6.1.2 For the welds of the spherical shell and the welds directly welded to the spherical shell, low-hydrogen coated electrodes shall be used, and diffusible hydrogen shall be retested according to the batch number. The diffusible hydrogen test method shall be carried out in accordance with the provisions of GB/T3965. The actual diffusible hydrogen content after drying shall comply with the provisions of Table 13.
Welding materials
E4315, E4316
E5015, E5016
E5515-X, E5516-X
E6015-X, E6016-X
J607RH
Flux-cored welding wire
4.6.2 Welding wire and flux
Diffusible hydrogen content, mL/100g
4.6.2.1 Welding wire and flux shall match the type of steel being welded. Welding wire and flux shall conform to the relevant provisions of GB/T 8110, GB/T10045, GB/T 12470, GB/T 14957, GB/T 14958 and GB/T5293 respectively.
4.6.2.2 Carbon dioxide and nitrogen for protection shall comply with the relevant provisions of GB/T6052 and GB/T4842 respectively. Gas cylinders shall be cleaned as required before use.
Usage status
Usage temperature limit, ℃
The structure of the spherical tank shall be determined in accordance with GB/T 17261. 5.1 Ball
5.1.1 The spherical shell consists of various belts and upper and lower poles, and its structure is shown in Figure 3.
Upper widow
Upper temperate zone
Equatorial zone
Underflow zone
Orange-petal type
Lower race zone
Mixed type
Figure 3 Schematic diagram of spherical shell structure
Upper temperate zone
Equatorial zone
Lower temperate zone
The minimum width of the spherical shell plate should not be less than 500mm. 5.1.2
The groove form of the spherical shell plate can be selected according to GB/T985 and GB/T986, or determined by referring to Appendix C "Groove form and size of spherical shell butt weld".
5.3 Connection between pillar and spherical shell
The connection between the pillar and the spherical shell adopted in this standard is the equatorial tangent type.
5.3.2 The connection between the pillar and the spherical shell can adopt the direct connection structure type [see Figure 4 (a)], the structure type with a support plate [see Figure 4 (6)], the U-shaped column structure type [see Figure 4 (c)] or the pillar flange structure type [see Figure 4 (d)].
5.4 Pillar
J-shaped column
(a). The intersection of the fixed tie rods is cross-welded or welded to the fixed plate, see Figure 6 (b).
5.4.1 The pillar should be made of steel pipe
5.4.2 The lower pillar can be divided into sections, and the length of the section should not be less than 1/3 of the total length of the pillar. The circumferential joints between the sections should be fully welded. A butt joint with a pad close to the base metal along the entire length of the weld root can be used.
5.4.3 The top of the pillar should be equipped with a spherical or circular rainproof cover.
5.4.4 The pillar should be equipped with a vent, and a fireproof layer should be provided for the spherical tanks storing flammable materials and liquefied petroleum gas, as shown in Figure 5. 5.4.5 A through hole should be provided in the center of the pillar bottom plate, as shown in Figure 5. 5.4.6 The anchor bolt holes of the pillar bottom plate should be radial oblong holes. 5.5 Tie rods
5.5.1 Tie rod structures are of two types: adjustable and fixed. The three-dimensional intersection of the adjustable tie rod shall not be welded, see Figure 61674
Also bolt holes
This standard only provides the calculation method for adjustable tie rods.1 The spherical shell is composed of various zones and upper and lower poles, and its structure is shown in Figure 3.
Upper widow's skirt
Upper temperate zone
Equatorial zone
Underflow zone
Orange-shaped
Lower race zone
Mixed
Figure 3 Schematic diagram of spherical shell structure
Upper temperate zone
Equatorial zone
Lower temperate zone
The minimum width of the spherical shell plate should not be less than 500mm. 5.1.2
The groove form of the spherical shell plate can be selected according to GB/T985 and GB/T986, or determined by referring to Appendix C "Groove form and size of spherical shell butt weld".
5.3 Connection between pillar and spherical shell
The connection between the pillar and the spherical shell adopted in this standard is the equatorial tangent type.
5.3.2 The connection between the pillar and the spherical shell can adopt the direct connection structure type [see Figure 4 (a)], the structure type with a support plate [see Figure 4 (6)], the U-shaped column structure type [see Figure 4 (c)] or the pillar flange structure type [see Figure 4 (d)].
5.4 Pillar
J-shaped column
(a). The intersection of the fixed tie rods is cross-welded or welded to the fixed plate, see Figure 6 (b).
5.4.1 The pillar should be made of steel pipe
5.4.2 The lower pillar can be divided into sections, and the length of the section should not be less than 1/3 of the total length of the pillar. The circumferential joints between the sections should be fully welded. A butt joint with a pad close to the base metal along the entire length of the weld root can be used.
5.4.3 The top of the pillar should be equipped with a spherical or circular rain cover.
5.4.4 The pillar should be equipped with a vent, and a fireproof layer should be provided for the spherical tanks storing flammable materials and liquefied petroleum gas, as shown in Figure 5. 5.4.5 A through hole should be provided in the center of the pillar bottom plate, as shown in Figure 5. 5.4.6 The anchor bolt holes of the pillar bottom plate should be radial oblong holes. 5.5 Tie rods
5.5.1 Tie rod structures are of two types: adjustable and fixed. The three-dimensional intersection of the adjustable tie rod shall not be welded, see Figure 61674
Also bolt holes
This standard only provides the calculation method for adjustable tie rods.1 The spherical shell is composed of various zones and upper and lower poles, and its structure is shown in Figure 3.
Upper widow's skirt
Upper temperate zone
Equatorial zone
Underflow zone
Orange-shaped
Lower race zone
Mixed
Figure 3 Schematic diagram of spherical shell structure
Upper temperate zone
Equatorial zone
Lower temperate zone
The minimum width of the spherical shell plate should not be less than 500mm. 5.1.2
The groove form of the spherical shell plate can be selected according to GB/T985 and GB/T986, or determined by referring to Appendix C "Groove form and size of spherical shell butt weld".
5.3 Connection between pillar and spherical shell
The connection between the pillar and the spherical shell adopted in this standard is the equatorial tangent type.
5.3.2 The connection between the pillar and the spherical shell can adopt the direct connection structure type [see Figure 4 (a)], the structure type with a support plate [see Figure 4 (6)], the U-shaped column structure type [see Figure 4 (c)] or the pillar flange structure type [see Figure 4 (d)].
5.4 Pillar
J-shaped column
(a). The intersection of the fixed tie rods is cross-welded or welded to the fixed plate, see Figure 6 (b).
5.4.1 The pillar should be made of steel pipe
5.4.2 The lower pillar can be divided into sections, and the length of the section should not be less than 1/3 of the total length of the pillar. The circumferential joints between the sections should be fully welded. A butt joint with a pad close to the base metal along the entire length of the weld root can be used.
5.4.3 The top of the pillar should be equipped with a spherical or circular rain cover.
5.4.4 The pillar should be equipped with a vent, and a fireproof layer should be provided for the spherical tanks storing flammable materials and liquefied petroleum gas, as shown in Figure 5. 5.4.5 A through hole should be provided in the center of the pillar bottom plate, as shown in Figure 5. 5.4.6 The anchor bolt holes of the pillar bottom plate should be radial oblong holes. 5.5 Tie rods
5.5.1 Tie rod structures are of two types: adjustable and fixed. The three-dimensional intersection of the adjustable tie rod shall not be welded, see Figure 61674
Also bolt holes
This standard only provides the calculation method for adjustable tie rods.
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