JB/T 4729-1994 Spinning Head JB/T4729-1994 Standard Download Decompression Password: www.bzxz.net

Industry Standard of the People's Republic of China
JB/T4729-94
Spinning Head
Spinning heads
1994-01-29 Issued
Ministry of Machinery Industry of the People's Republic of China
Ministry of Chemical Industry of the People's Republic of China
Ministry of Labor of the People's Republic of China
China Petrochemical Corporation
1994-05-01 Implementation
Subject content and scope of application
Cited standards
Symbol description
Type and basic parameters
Technical requirementswww.bzxz.net
Inspection method
Inspection rules
Quality certification documents
Marking, packaging and transportation
Appendix A
Head data (reference number)
Main content and scope of application
Industry standards of the People's Republic of China
Spinning heads
Spinning heads
JB/T4729—94
This standard specifies the types, parameters, technical requirements, inspection methods, marking, packaging, transportation, etc. of spun heads. This standard applies to cold-spun heads for steel welded pressure vessels (hereinafter referred to as "heads"). 2 Reference standards
GB150 Steel pressure vessels
JB2536 Oil spill, packaging and transportation of pressure vessels JJG1 Inspection procedures for steel rulers
JG4 Inspection procedures for steel tape measures
3 Symbols
Inner diameter of head, mm;
H—Total depth of head. mm;
H.-—Total height of the cone of the large-end folded conical head, mm; h-Height of the straight edge of the head, mm;
h,-i Depth of the curved surface of the head, mm;
h. Cone height of the large-end folded conical head, mmR,—Inner radius of the spherical part of the dished head, spherical crown head and hemispherical head, mm; dished head, large-end folded The inner radius of the transition zone of the conical head and the flat head with folded edge, mm; .-Nominal thickness of the head, mm;
αThe semi-apex angle of the cone shell, ().
4 Types and basic parameters
4.1 The name, cross-sectional shape, type code and shape parameter examples of the head are shown in Table 1. 4.2. The nominal diameter of the head is shown in Table 2. The nominal diameter refers to the inner diameter of the head. 4.3 The head parameters are shown in Appendix A (reference). Ministry of Machinery Industry of the People's Republic of China
Ministry of Chemical Industry of the People's Republic of China
Ministry of Labor of the People's Republic of China
China Petrochemical Corporation
Approved on January 29, 1994
Implemented on May 1, 1994
Oyster
Spherical
Folded edge flat|| tt||Large end fold
Edge cone
Hemispherical
Note: Folded flat heads shall not be used for pressure vessels2
JB/T4729-94
Examples of common shape parameters
D,/(2h,)=2
Nominal diameter
Nominal diameter
4.4·The model marking of the head shall be as followsx
JB/T4729-94
Nominal diameter
Standard number
Nominal diameter
Straight edge height.mm
Nominal diameter
Depth of curved surface or semi-apex angle of cone shell, mm or (°) Nominal thickness, mm
Inner diameter.mm
Head type code. According to Table 1| |tt||For the heads with shape parameters in the example in Table 1, the depth of the curved surface or the semi-apex angle of the cone shell and the height of the straight edge may not be marked. Model marking example
Elliptical head with inner diameter of 5000mm, nominal thickness of 18mm and shape parameter of D./(2h)=2: EH5000X18
JB/T4729-94
Large-end folded cone head with inner diameter of 4600mm, nominal thickness of 20mm, semi-apex angle of cone shell of 45° and straight edge height of 50mm: b.
CH4600×20×45°×50
JB/T4729--94
5 Technical requirements
5.1 Materials
5.1.1 The head material shall comply with the relevant provisions and drawing requirements of GB150. 5.1.2 The head material is not allowed to have defects such as cracks, bubbles, scars, folds, inclusions and delamination. 5.2 Manufacturing
5.2.1 Preparation of blanks
5.2.1.1 The blanks of the head should be made of whole plates. If splicing is required, the plates of the same batch number should be used. And the same sheet should be used as much as possible. 5.2.1.2 When the plates are spliced, the distance from the outermost weld to the center of the plate a≤0.4D, and the minimum plate width h shall not be less than 300mm (see Figure 1).
5.2.1.3 The misalignment of the joints in the assembly of the panels shall not exceed 8% of the thickness of the blanks and shall not exceed 1.5mm. 5.2.1.4 The welding and quality requirements of the spliced ​​welds shall comply with the relevant provisions of GB150. The spliced ​​welds shall be ground to be flush with the parent material. 5.2.1.5 After the blank is rounded, the periphery should be polished and smooth, and the end face should not have defects such as cracks, bubbles, inclusions and delamination. 5.2-2 Forming
The head should be formed by cold spinning-one-step method or two-step method. Note: The method of forming by one-step spinning is called one-step method. The method of forming by two steps of drum pressing and flanging is called two-step method3
5.2.3 Post-cold forming treatment
JB/T472994
Note: D
Blank material diameter.
The head should be heat treated after cold forming. When the manufacturing unit ensures that the material properties meet the design and use requirements after cold spinning, it is not subject to this limitation. Unless otherwise specified in the drawing, austenitic stainless steel heads do not need to be heat treated. 5.2.4 Edging and beveling
5.2.4.1 For heads made of carbon steel and low alloy steel, mechanical or gas cutting methods can be used for edging and beveling; for heads made of stainless steel, mechanical or plasma cutting methods should be used for edging and beveling. 5.2.4.2 The beveling type shall be in accordance with the requirements of the drawing or order contract. 5.3 Dimension and shape deviation
5.3.1 Inner diameter tolerance
The inner diameter tolerance of the head is allowed to be controlled by the outer circumference, and the outer circumference tolerance is in accordance with Table 3. Table 3
Nominal thickness 8
5.3.2 Maximum and minimum inner diameter difference
Inner diameter D,
300≤D2000
2000
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