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Industry Standard of the People's Republic of China
20531-93
Cast Steel and Cast Iron Containers
1993-07-13
1993-11-01
Ministry of Chemical Industry of the People's Republic of China
Industry Standard of the People's Republic of China
Cast Steel and Cast Iron Containers
HG 20531-93
Editor: The Fourth Design Institute of the Ministry of Chemical Industry
Approval Department: The Ministry of Chemical Industry
Effective Date: November 1, 1993
Editorial Center for Engineering Construction Standards of the Ministry of Chemical Industry
Document of the Ministry of Chemical Industry
Chemical Base Development (1993) No. 526
Notice on Approving "Cast Steel and Cast Iron Containers" as Chemical Industry Standards
To the Chemical Industry Departments (bureaus, general companies) of provinces, autonomous regions, and municipalities directly under the Central Government, Chemical Industry Bureaus of Cities with Independent Planning Lists, and all design units:
"Cast Steel and Cast Iron Containers" organized by the Equipment Design Technology Center of the Ministry of Chemical Industry and edited by the Fourth Design Institute of the Ministry of Chemical Industry has been reviewed and approved as a chemical industry standard. The number is HG20531-93 and it will be implemented from October 1993. Ministry of Chemical Industry
July 13, 1993
Regulations to be followed
Design and manufacturing units
Allowable stress
Mesh blue sub-blue
Pressure test and density test
General requirements for materials
Gray cast iron
Ductile cast iron
Mallet cast iron
High silicon corrosion-resistant cast iron
Heat-resistant cast iron
Carbon cast steel and stainless acid-resistant cast iron SteelbzxZ.net
Xie Re Cast Steel
Strength Calculation
General Principles
Tower Vessel Calculation
3.3 External Pressure Shell Calculation
4 Structural Design
General Principles and Precautions for Structural Design 41
4.2 Characteristics of Structural Design of Non-casting Materials
Casting Node Design
4.4 Design of Casting Vessel Components
4.5 Structural Design of Tower Vessel
Manufacturing, inspection and acceptance
5.1 Principles to be followed
5.2 Materials
Surface quality and allowable defects
Heat treatment
Parts tolerance
Repair of casting defects
General provisions for inspection
Pressure test and tightness test
Hydraulic destructive test of cast iron vessels
Quality certification documents, painting, packaging, transportation 6
Appendix A
Typical casting container (reference)
Appendix B
Casting casting addition (reference)
Article explanation
1.1 Regulations to be followed
The design, manufacture, inspection and acceptance of cast steel and cast iron containers and their parts within the scope of this standard shall comply with the provisions of this standard and other relevant cast steel and cast iron standards. Among them, cast steel and cast iron pressure vessels shall also comply with the "Regulations on Safety Technical Supervision of Pressure Vessels" of the Ministry of Labor.
1.2 Scope
1.2.1 The scope of design pressure and design temperature applicable to this standard. According to the different materials of cast steel and cast iron, the specific provisions are as follows: 1.2.1.1 The design pressure of gray cast iron pressure vessels shall not be greater than 0.8MPa, and the design temperature is 0250℃
1.2.1.2 The design pressure of malleable cast iron and ductile iron pressure vessels shall not be greater than 1.6MPa, and the design temperature is -10~350℃. 1.2.1.3 Heat-resistant cast iron components can be used up to 550~1100C according to different material grades, see GB9437-88 "Hot Cast Iron Parts" Record B1.2.1.4 The design humidity of high silicon corrosion-resistant cast iron components is 0-~250℃. 1.2.1,5 The design pressure of cast steel pressure vessels should not exceed 6.4MPa when used for pressure vessels, and can be used up to 10.0MPa when used for other pressure components (such as flanges, flat covers, etc.). The lower limit of design leakage is above 20C (excluding 200), and the upper limit of design temperature: carbon and low alloy cast steel is 475C, chromium-molybdenum alloy and stainless steel cast steel are alternately with the upper limit of the use temperature of plates or pipes of the same grade, see GB150-89 "Steel Pressure Vessels". ：1.2.2 The diameter limit range of gray cast iron pressure vessels is as follows: 1
Design internal pressure ≤0.3MPa, inner diameter ≤3000mm; design internal pressure ≤0.8MPa, inner diameter ≤1000mm; design external pressure ≤0.8MPa, inner diameter ≤2000mm1.2.3 The scope of application of this standard refers to the container and the connected cast steel or cast iron parts as a whole. All kinds of pipe fittings and pipelines other than the first flange sealing surface, the first threaded joint and the first sealing surface connected to the cast container with special connectors or pipe fittings are not within the scope of this standard. Other non-casting parts connected to the cast container, such as parts made of rolled plates, pipes, bars or forgings of carbon steel, low alloy steel, alloy steel, stainless steel, etc., are also not within the scope of this standard. 1.2.4 Cast iron materials shall not be used for pressure components of pressure vessels containing extremely, highly or moderately toxic media and flammable media, or components of non-normal pressure vessels with a pressure of not less than 0.005MPa, nor for pressure components of shell and tube waste heat boilers. 1.2.5 This standard does not apply to the following types of vessels: 1.2.5.1 Pressure vessels heated by direct flames; 1.2.5.2 Containers subjected to radiation:
1.2.5.3 Containers frequently transported:
1.2.5.4 Containers requiring fatigue analysis. 1.2.6 Classification of pressure vessels
All cast steel or cast iron vessels that meet the three conditions of the "Regulations on Safety Technical Supervision of Pressure Vessels" are pressure vessels and are subject to supervision by the supervision regulations. Cast steel or cast iron vessels with a design pressure less than 0.005MPa are normal pressure vessels. 1.3 Design and manufacturing units
1.3.1 The units that design and manufacture cast steel or cast iron pressure vessels must have a sound and comprehensive quality management system. The design unit shall hold a design unit approval letter for pressure vessels of the corresponding scope, and the manufacturing unit shall hold a manufacturing license for pressure vessels of the corresponding scope. The unit that manufactures cast iron pressure vessels must have a long production history, a certain level of production and experience, and relatively advanced equipment conditions. 1.3.2 Responsibilities of the design unit
The design unit shall be responsible for the accuracy and completeness of the design documents. 1.3.2.1-
1.3.2.2 The design documents of cast vessels shall at least include design calculations and design drawings. The general design drawing of cast pressure vessels shall be stamped with the approval seal of the pressure vessel design unit.
1.3.3 Responsibilities of the manufacturing unit
1.3.3.1 The manufacturing unit must carry out casting and processing in accordance with the requirements of the design drawings. If the original design needs to be modified, the written approval of the original design unit shall be obtained. 1.3.3.2 During the manufacturing process and after the completion of the container, the inspection department of the manufacturing unit shall carry out various specific inspections and tests on the container in accordance with the provisions of this standard and the drawings, submit an inspection report, and be responsible for the accuracy and completeness of the report. 1.3.3.3 The manufacturing unit shall have at least the following technical documents for reference for each cast container it manufactures, and the technical documents shall be kept for at least 7 years: (1) Manufacturing process drawings or manufacturing process cards; (2) Material certification documents:
(3) Casting process and heat treatment process records
(4) Records of items that the manufacturer is allowed to select in the standard: (5) Inspection records during the manufacturing process and after the completion of the container: (6) As-built drawings of the container.
1.3.3.4 After the manufacturer obtains confirmation from the authorized inspection agency that the quality of the pressure vessel meets the requirements of this standard and drawings of the "Regulations on Safety Technical Supervision of Pressure Vessels", it must fill in the product quality certificate and deliver it to the user. 1.3.4 The statutory or authorized boiler pressure vessel inspection agency shall conduct supervision and inspection of cast pressure vessels in accordance with relevant national regulations, laws and regulations and relevant provisions included in the supervision clauses of this standard.
1.4 Definitions
1.4.1 Pressure refers to gauge pressure unless otherwise specified. 1.4.2 Maximum working pressure Maximum working pressure refers to the highest pressure that may occur at the top of the container under normal operating conditions.
1.4.3 Design pressure Design pressure refers to the pressure at the corresponding design temperature to determine the thickness of the container shell manually, that is, the container design pressure marked on the nameplate, and its value shall not be less than the maximum working pressure.
When the static pressure of the liquid column borne by each part of the container or the pressure-bearing component reaches 5% of the design pressure, the sum of the design pressure plus the static pressure of the liquid column shall be taken for the design calculation of the part or component.
When a safety relief device is installed on the container, the design pressure of the container shall be determined in accordance with the relevant provisions of Appendix B of GB150-89 "Steel Pressure Vessels". The design pressure of the external pressure container shall not be less than the maximum internal and external pressure difference that may occur under normal operation.
Vacuum vessels are designed to withstand external pressure. When equipped with a safety control device (such as a vacuum relief valve), the design pressure is the set pressure of the relief valve, that is, 1.25 times the maximum internal and external pressure difference, or 0.1MPa, whichever is smaller. When there is no safety control device, 0.1MPa is taken.
For jacketed vessels, when calculating the inner container with the jacket, the possible internal and external pressure difference under normal operation should be considered. 1.4.4 Metal temperature Metal temperature refers to the average temperature of the pressure-bearing components of the vessel along the cross-sectional thickness. In any case, the surface temperature of the component metal shall not exceed the allowable use temperature of the material.
1.4.5 Design temperature Design temperature refers to the metal temperature of the pressure-bearing components set under normal operation and at the corresponding design pressure of the vessel, and its value shall not be lower than the highest metal temperature that the component metal may reach. For metal temperatures below 0°C, the design temperature shall not be higher than the lowest metal temperature that the component metal may reach. The design temperature of the vessel (i.e. the design temperature marked on the nameplate of the vessel) refers to the design temperature of the shell. Note: For vessels with different operating conditions, the corresponding design pressure and design temperature for each severe condition should be stated in the drawings or relevant technical documents. 1.4.6 Test temperature The test temperature refers to the metal temperature of the vessel shell during the pressure test.
1.5 Loads
The following loads should be considered during design:
1.5.1.1 Design pressure;
1.5.1.2 Liquid static pressure;
1.5.1.3 The dead weight of the container and the gravity load of the material inside under normal operating conditions or test conditions;
1.5.1.4 The gravity load of auxiliary components, insulation materials, pipelines, etc.; 1.5.1.5 Wind load and seismic load:
If necessary, the influence of the following loads should also be considered: 1.5.1.6 The reaction force of the support;
1.5.1.7 The force caused by connecting pipelines and other components; 1.5.1.8 The force caused by different thermal expansion amounts; 1.5.1.9
The influence of pressure and temperature changes;
The forces that the container is subjected to during transportation and lifting. 1.6 Thickness
1.6.1 Thickness Addition
The thickness addition C is determined according to formula (1.6.1): C=Ci+Ca
Wu Zhong:
Ci-negative thickness deviation, mm;
For double-sided machining, Ci=0 can be taken. For single-sided machining or non-machining, according to GB6414-86 "Tolerances on casting dimensions", C1 is taken according to the following steps: 1.6.1.1 According to batch and mass production or small batch and single piece production, as well as the importance of the casting, select the general size tolerance grade of the casting from Table 1.6.1.1-1 or Table 1.6.1.1-2 (for example: CT10), and select the thickness tolerance grade one level lower (for example: CT11): 1.6.1.2 According to the selected thickness tolerance grade, the thickness is also used as the basic size of the casting, and the corresponding tolerance CT value (for example: 4.0mm) is found from Table 1.6.1.2 1.6.1.3 Usually the tolerance zone is symmetrically distributed, that is, half of it is positive and half of it is negative, then Ci=CT value/2 (for example: 2.0mm); if there are special requirements and the asymmetrical arrangement is indicated on the drawing, then C1 takes the actually selected negative tolerance value. C-.Corrosion allowance, mm; determined according to the corrosiveness of the medium, for non-stainless steel castings, take C, not less than 1mm; for stainless steel castings, when the medium corrosion is very slight, take Cz0.
For the casting addition, it is related to the casting method and can be added by the casting manufacturer when considering the casting process, but this value can be ignored on the drawing. Dimensional tolerance grades of castings for batch and mass production Casting process methods
Sand mold hand molding
Sand mold machine molding and shell mold
Metal mold
Low pressure casting
Investment casting
Gray cast iron
Table 1.6.1.1-1
Ductile cast iron
Mallet cast iron
11~～13
Dimensional tolerance grades of castings for small batch and single piece production Molding materials
Dry and wet sand
Self-hardening sand
Basic dimensions of castings
12～14
Gray cast iron
11～13
Dimensional tolerance values of castings
0.38 0.540.78
0.460.640.90
0.560.781.1
0.620.881
Table 1.6.1.1-2
Ductile iron
11～13
Mallet cast iron
Table 1.6.1.2
Note: For basic dimensions of castings with CT13~~CT16 less than or equal to 16mm, the tolerance grade can be increased by 2~~3 grades.
1.6.2 Minimum thickness
To meet the requirements of casting and machining process, according to practical experience, the minimum thickness of castings is 73. Usually the tolerance zone is symmetrically distributed, that is, half of it is positive and half of it is negative. Then Ci is CT value/2 (for example: 2.0mm); if there are special requirements and the asymmetrical arrangement is indicated on the drawing, then C is the actual selected negative tolerance value. C-.-Corrosion allowance, mm; determined according to the corrosiveness of the medium, for non-stainless steel castings, take C, not less than 1mm; for stainless steel castings, when the medium corrosion is extremely slight, take Cz0.
For the casting addition, it is related to the casting method and can be added by the casting manufacturer when considering the casting process, but this value can be ignored on the drawing. Dimensional tolerance grades of castings for batch and mass production Casting process methods
Sand mold hand molding
Sand mold machine molding and shell mold
Metal mold
Low pressure casting
Investment casting
Gray cast iron
Table 1.6.1.1-1
Ductile cast iron
Mallet cast iron
11~～13
Dimensional tolerance grades of castings for small batch and single piece production Molding materials
Dry and wet sand
Self-hardening sand
Basic dimensions of castings
12～14
Gray cast iron
11～13
Dimensional tolerance values of castings
0.38 0.540.78
0.460.640.90
0.560.781.1
0.620.881
Table 1.6.1.1-2
Ductile iron
11～13
Mallet cast iron
Table 1.6.1.2
Note: For basic dimensions of castings with CT13~~CT16 less than or equal to 16mm, the tolerance grade can be increased by 2~~3 grades.
1.6.2 Minimum thickness
To meet the requirements of casting and machining process, according to practical experience, the minimum thickness of castings is 73. Usually the tolerance zone is symmetrically distributed, that is, half of it is positive and half of it is negative. Then Ci is CT value/2 (for example: 2.0mm); if there are special requirements and the asymmetrical arrangement is indicated on the drawing, then C is the actual selected negative tolerance value. C-.-Corrosion allowance, mm; determined according to the corrosiveness of the medium, for non-stainless steel castings, take C, not less than 1mm; for stainless steel castings, when the medium corrosion is extremely slight, take Cz0.
For the casting addition, it is related to the casting method and can be added by the casting manufacturer when considering the casting process, but this value can be ignored on the drawing. Dimensional tolerance grades of castings for batch and mass production Casting process methods
Sand mold hand molding
Sand mold machine molding and shell mold
Metal mold
Low pressure casting
Investment casting
Gray cast iron
Table 1.6.1.1-1
Ductile cast iron
Mallet cast iron
11~～13
Dimensional tolerance grades of castings for small batch and single piece production Molding materials
Dry and wet sand
Self-hardening sand
Basic dimensions of castings
12～14
Gray cast iron
11～13
Dimensional tolerance values of castings
0.38 0.540.78
0.460.640.90
0.560.781.1
0.620.881
Table 1.6.1.1-2
Ductile iron
11～13
Mallet cast iron
Table 1.6.1.2
Note: For basic dimensions of castings with CT13~~CT16 less than or equal to 16mm, the tolerance grade can be increased by 2~~3 grades.
1.6.2 Minimum thickness
To meet the requirements of casting and machining process, according to practical experience, the minimum thickness of castings is 7
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