In what situations is the analytical method JB4732 used for pressure vessel design? Urgent need
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In what situations is the analytical method JB4732 used for pressure vessel design? Urgent need
It was at the customer’s request; the customers are usually large chemical companies abroad
This post was last edited by xlxuiin on 2016-11-29 at 16:22: http://bbs.hcbbs.com/thread-510090-1-1.html Scope of application and main differences among GB150, JB4732, and JB/T4735
| Item | GB150 “Steel Pressure Vessels” | JB4732 “Steel Pressure Vessels – Analysis Design Criteria” | JB/T4735 “Steel Welded Atmospheric Pressure Vessels” |
|------|-------------------------------|----------------------------------------------------------|--------------------------------------------------------|
| Design pressure | 0.1 MPa ≤ pd ≤ 35 MPa, vacuum level not lower than 0.02 MPa | 0.1 MPa ≤ pd < 100 MPa, vacuum level not lower than 0.02 MPa | -0.02 MPa < pd < 0.1 MPa |
| Design temperature | Determined according to the allowable operating temperature of the steel (up to 700°C, as low as -196°C) | Below the temperature at which the design stress strength is controlled by steel creep (up to 475°C) | From -20°C to 350°C (This restriction does not apply to vessels made of austenitic high-alloy steel, or to vessels with a design temperature below -20°C that are designed for low-temperature, low-stress conditions and have an adjusted design temperature above -20°C) |
| Basic safety factors | Carbon steel, low-alloy steel: nb ≥ 3.0, ns = nts ≥ 1.6, nD ≥ 1.5, nn ≥ 1.0 | | |； High-alloy steel: nb≥3.0, ns=nts≥1.5, nD≥1.5, nn≥1.0; Carbon steel, low-alloy steel, ferritic high-alloy steel: nb≥2.6, ns=nts≥1.5 ； Austenitic high-alloy steels: ns=nts≥1.5; carbon steels, low-alloy steels, ferritic high-alloy steels: nb≥2.5, ns=nts≥1.5 ； Austenitic high-alloy steel: ns=nts≥1.5. No restrictions on the medium. Not applicable to containers used for holding highly toxic or extremely hazardous media. Design criteria include elastic failure design criteria, plastic failure design criteria, and fatigue failure design criteria; local stresses are evaluated using limit analysis and stability analysis results. Generally, elastic failure design criteria and instability failure design criteria are used. Stress analysis methods are based on principles of material mechanics and shell theory formulas, with the addition of stress amplification factors and shape factors – elastic finite element method; plastic analysis; plastic theory and shell theory formulas; experimental stress analysis is also based on material mechanics and shell theory formulas, with the inclusion of stress amplification factors and shape factors. Strength theories include the maximum principal stress theory, the maximum shear stress theory, etc., but the design thickness of most containers is determined by the minimum thickness requirement. There are no requirements for non-destructive testing of container shells. Non-destructive testing requirements depend on the type of steel, thickness, properties of the medium, and type of pressure test; local non-destructive testing requires that the length be at least 20% of the length of each weld seam, and at least 250 mm for all Class A or B weld joints; for Class C weld joints where the nominal thickness of the cylinder or head is greater than 65 mm (except for those in multi-layer wrapped cylinders), and for Class D weld joints where the diameter of the opening is greater than 100 mm and the nominal thickness of the cylinder or head is greater than 65 mm, 100% non-destructive testing is required. Whether non-destructive testing is necessary depends on the nominal volume of the container, thickness, design temperature, toxicity and flammability of the medium, type of pressure test, and type of steel; the testing length should be at least 10% of the length of each weld seam. Stress analysis is not required, but it is necessary when the conditions specified in this standard are exceeded. It is not required for spherical shells, cylinders, heads, etc. designed in accordance with this standard. Fatigue analysis is not applicable to containers that require fatigue analysis. It is required, but there are exemptions (fatigue analysis may be waived based on the number of load cycles or stress amplitude). It is not applicable to containers that require fatigue analysis. Qualification requirements: Design and manufacturing units must have the appropriate design approval documents or manufacturing licenses; welding must be carried out by welders with the appropriate qualifications; non-destructive testing must be performed by personnel with the appropriate qualifications. Design units must have qualifications for stress analysis design, and design documents must be signed by three qualified analysts and designers. Manufacturing units must have a manufacturing license for Category III containers; welding must be carried out by welders with the appropriate qualifications; non-destructive testing must be performed by Level I or Level II personnel. There are no qualification requirements for design or manufacturing; for containers that require non-destructive testing, it must be performed by personnel with relevant qualifications; for some containers, welders with valid certification are required. Overall economic efficiency: Containers with simple structures have good overall economic efficiency. Containers with large and complex structures also have good overall economic efficiency. Containers within the appropriate range have good overall economic efficiency
| Item | GB150 “Steel Pressure Vessels” | JB4732 “Steel Pressure Vessels – Analysis Design Criteria” | JB/T4735 “Steel Welded Atmospheric Pressure Vessels” |
|------|-------------------------------|----------------------------------------------------------|--------------------------------------------------------|
| Design pressure | 0.1 MPa ≤ pd ≤ 35 MPa, vacuum level not lower than 0.02 MPa | 0.1 MPa ≤ pd < 100 MPa, vacuum level not lower than 0.02 MPa | -0.02 MPa < pd < 0.1 MPa |
| Design temperature | Determined according to the allowable operating temperature of the steel (up to 700°C, as low as -196°C) | Below the temperature at which the design stress strength is controlled by steel creep (up to 475°C) | From -20°C to 350°C (This restriction does not apply to vessels made of austenitic high-alloy steel, or to vessels with a design temperature below -20°C that are designed for low-temperature, low-stress conditions and have an adjusted design temperature above -20°C) |
| Basic safety factors | Carbon steel, low-alloy steel: nb ≥ 3.0, ns = nts ≥ 1.6, nD ≥ 1.5, nn ≥ 1.0 | | |； High-alloy steel: nb≥3.0, ns=nts≥1.5, nD≥1.5, nn≥1.0; Carbon steel, low-alloy steel, ferritic high-alloy steel: nb≥2.6, ns=nts≥1.5 ； Austenitic high-alloy steels: ns=nts≥1.5; carbon steels, low-alloy steels, ferritic high-alloy steels: nb≥2.5, ns=nts≥1.5 ； Austenitic high-alloy steel: ns=nts≥1.5. No restrictions on the medium. Not applicable to containers used for holding highly toxic or extremely hazardous media. Design criteria include elastic failure design criteria, plastic failure design criteria, and fatigue failure design criteria; local stresses are evaluated using limit analysis and stability analysis results. Generally, elastic failure design criteria and instability failure design criteria are used. Stress analysis methods are based on principles of material mechanics and shell theory formulas, with the addition of stress amplification factors and shape factors – elastic finite element method; plastic analysis; plastic theory and shell theory formulas; experimental stress analysis is also based on material mechanics and shell theory formulas, with the inclusion of stress amplification factors and shape factors. Strength theories include the maximum principal stress theory, the maximum shear stress theory, etc., but the design thickness of most containers is determined by the minimum thickness requirement. There are no requirements for non-destructive testing of container shells. Non-destructive testing requirements depend on the type of steel, thickness, properties of the medium, and type of pressure test; local non-destructive testing requires that the length be at least 20% of the length of each weld seam, and at least 250 mm for all Class A or B weld joints; for Class C weld joints where the nominal thickness of the cylinder or head is greater than 65 mm (except for those in multi-layer wrapped cylinders), and for Class D weld joints where the diameter of the opening is greater than 100 mm and the nominal thickness of the cylinder or head is greater than 65 mm, 100% non-destructive testing is required. Whether non-destructive testing is necessary depends on the nominal volume of the container, thickness, design temperature, toxicity and flammability of the medium, type of pressure test, and type of steel; the testing length should be at least 10% of the length of each weld seam. Stress analysis is not required, but it is necessary when the conditions specified in this standard are exceeded. It is not required for spherical shells, cylinders, heads, etc. designed in accordance with this standard. Fatigue analysis is not applicable to containers that require fatigue analysis. It is required, but there are exemptions (fatigue analysis may be waived based on the number of load cycles or stress amplitude). It is not applicable to containers that require fatigue analysis. Qualification requirements: Design and manufacturing units must have the appropriate design approval documents or manufacturing licenses; welding must be carried out by welders with the appropriate qualifications; non-destructive testing must be performed by personnel with the appropriate qualifications. Design units must have qualifications for stress analysis design, and design documents must be signed by three qualified analysts and designers. Manufacturing units must have a manufacturing license for Category III containers; welding must be carried out by welders with the appropriate qualifications; non-destructive testing must be performed by Level I or Level II personnel. There are no qualification requirements for design or manufacturing; for containers that require non-destructive testing, it must be performed by personnel with relevant qualifications; for some containers, welders with valid certification are required. Overall economic efficiency: Containers with simple structures have good overall economic efficiency. Containers with large and complex structures also have good overall economic efficiency. Containers within the appropriate range have good overall economic efficiency
It is an issue that takes into account design parameters, safety, cost, the level of design and manufacturing, as well as usage and management, and requirements are often put forward by the users of the equipment.
When the design pressure is greater than 35 MPa, stress analysis methods must be used for design.
In other words, can high-pressure vessels with a pressure exceeding 35 MPa, which is above the range specified in GB150, only be tested using the analysis method JB4732?
Passed by, learned*, straight to the 3rd floor roof.
No, the 4732 also has a pressure limit; if the pressure exceeds 100 Mpa, then the 4732 can no longer be used either
Containers subjected to fatigue loads should be designed using analytical methods...