HG/T 21573.4-1995 Spherical Washer HG/T21573.4-1995 Standard download decompression password: www.bzxz.net

Spherical washers
HG/T21573.4-95
Subject content and scope of application
This standard specifies the structural dimensions and technical requirements of spherical washers for H-type, HI-type and HR-type large-diameter nuts used in flange and manhole flange connections of pressure vessels. 55
GB2106
HG/T21573.1
HG/T21573.2
HG/T21573.3
Cited standards
"Technical conditions for high-quality carbon structural steel"
"Steel pressure vessels"
"Steel shell and tube heat exchangers"
"Metal tensile test method"||t t||Metal Brinell Hardness Test Method
Metal Charpy (V-Notch) Impact Test Method" "Steel Chemical Container Material Selection Regulations" "Bolt Hydraulic Tightening Device Series"
"Large Diameter Studs"
"Large Diameter Nuts"
3 Types, Dimensions and Weights of Spherical Washers
The types of spherical washers are shown in Figure 3-1, which are divided into Type A and Type B. Type A is used with H-type and HI-type nuts, and Type B is used with HR-type nuts. The dimensions and weights of spherical washers are specified in Table 3-1. D
Figure 3-1
Washer specifications
Spherical washer size and weight table
Table 3-1
Spherical washer materials and manufacturing technical requirements
4.0.1 The materials for spherical washers shall comply with the provisions of GB699, and the heat treatment system and mechanical properties after heat treatment shall be in accordance with the provisions of Table 4.0.1.
Tensile strength
Material standard
Washer specifications
48~140
48~140
Heat treatment system
≥375
≥490
≥540
Yield point
≥225
≥315
Elongation
After the material is heat treated, each washer must be inspected for hardness. The hardness requirements are as specified in Table 4.0.2. Steel
Spherical surface is not allowed to have defects such as grooves and scratches HB
Impact energy
5 Marking examples and steel stamp marking
5.1 Marking method
HG/T ××.×-××
Spherical washer standard number
Spherical washer
Washer specifications
X×-XX
5.2 Marking example
Washer type
Example 1: Spherical washer with nominal diameter of 64mm, material of 15 and type A, its marking is: HG/T21573.4-95·Spherical washer 64-A15Example 2: Spherical washer with nominal diameter of 80mm, material of 30Mn and type B, its marking is HG/T21573.4-95 Spherical washer 80-B30Mn5.3 Stamp marking
The manufacturer of spherical washers should mark the material brand with a stamp on the side of the washer. 60
Additional Notes
Proposer, Editor-in-Chief
and Main Drafters of this Standard
Proposer: Equipment Design Technology Center of the Ministry of Chemical Industry Editor-in-Chief: China Wuhuan Chemical Engineering Company Main Drafters: Liu Youyi
Approval: Wang Ronggui
Approval: Yao Peixian and Yao Beiquan
1. Purpose of Preparation
High-pressure Bolts and Hydraulic Bolt Tightening Deviceswww.bzxz.net
HG/T21573—95
Preparation Notes
(1) Bolt connection design is an important part of pressure vessel design. In the bolt standards recommended for pressure vessel equipment flanges in my country (such as JB4707 and H standards), the maximum bolt specification is M45, which is far from meeting the needs of pressure vessel design, especially high-pressure vessel design. In the past, in the design of high-pressure vessels, large-diameter bolts, nuts and washers with specifications equal to or greater than M48 were usually designed by the designers themselves, resulting in a large amount of design work, a variety of bolt and nut structures and sizes, which brought many inconveniences to the design management work and also affected the standardization process of high-pressure vessel design. (2) There are two methods for tightening bolts: manual tightening and mechanical tightening, and hydraulic tightening is the most commonly used mechanical tightening method. However, among the high-pressure bolts currently used and designed in pressure vessels in my country, most of them are still tightened manually because the tightening devices have not yet been standardized. This tightening method is not only labor-intensive and labor-intensive, but also difficult to control the tightening force, and often fails to achieve the expected sealing effect. Mechanical tightening can avoid the above-mentioned shortcomings of manual tightening, that is, it can save labor and reduce labor intensity, and can control the tightening force according to design requirements. Based on the above situation, in order to meet the design needs of pressure vessels, especially high-pressure vessels, according to the requirements of the Ministry of Chemical Industry's Infrastructure Department (91) Chemical Foundation Standard No. 21, based on the experience of using garbage collection and introduction devices and referring to the requirements of bolt structures and bolt hydraulic tightening devices at home and abroad, the standard "High-pressure Bolts and Bolt Hydraulic Tightening Devices" was compiled. 2. Scope of application
The scope of application of this standard is mainly determined based on the current status and development trend of pressure vessel design in my country. The specifications of its studs, nuts and washers are M48~M140. The operating temperature range is determined according to the material of the studs, and the specific requirements are specified in Table 28 of GB150-89.
The type and specification of the hydraulic bolt tightening device are compatible with the type and specification of the tightening studs and nuts. When used in pressure vessels, the types of its sealing gaskets are metal flat gaskets, toothed combination gaskets, and double cone gaskets. Based on the capacity of the hydraulic tightening device for bolts, this standard stipulates that the maximum specification of studs that the hydraulic tensioner can adapt to for pressure vessels using metal flat gaskets and toothed combination gaskets is M80; for pressure vessels sealed with double-cone gaskets, all the specifications of hydraulic tensioners listed in this standard can be used. If the sealing gasket is of other types or used on other mechanical equipment, the bolt tightening force should be determined first according to the requirements and the capacity of the hydraulic bolt tightening device should be checked. The required bolt tightening force should be less than the maximum tensile force specified by the selected hydraulic tensioner. 3. Specifications and types of studs
(1) This standard refers to DIN2510 and the current status and development trend of domestic pressure vessels and includes a total of 16 stud specifications, all with a pitch of 4mm. That is: M48×4, M52×4, M56×4, M64×4, M72×4, M80×4, M85X4M90×4, M100×4, M105×4, M110×4, M115×4, M120×4, M125×4, M130×4, M140×4. The minimum specification is M48 and the maximum specification is M140. The determination of its specifications mainly considers the following factors: ① It is connected with the specifications of the screw inspection used by existing domestic high-pressure equipment; ② It adapts to the requirements of large-scale chemical equipment; ③ It retains the bolt specifications already adopted by existing domestic high-pressure equipment and the habit of using fine pitch threads. (2) This standard lists two types of stud structures: one is a screw-in double-head stud
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